Warfarin

Potentiates anticoagulant response resulting in serious or fatal bleeding. Increases prothrombin time by 100%. Reduce warfarin dose by one-third to one-half.

Warfarin should not be used in patients requiring anticoagulation; use low-molecular weight or standard heparin instead due to CYP2C9 and CYP3A4 metabolism interactions.

Warfarin should not be used in patients requiring anticoagulation; use low-molecular weight or standard heparin instead due to CYP2C9 and CYP3A4 metabolism.

Mitotane induces warfarin metabolism, reducing its level and efficacy. Avoid concomitant use; if unavoidable, monitor INR and adjust dose.

Anticoagulant. Avoid concurrent use due to increased bleeding risk unless benefit outweighs risk.

Ibuprofen and warfarin have synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Ibuprofen and warfarin have synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Anticoagulant that increases bleeding risk when coadministered with apixaban. Concomitant use with aspirin and warfarin increased major bleeding from 2.7% to 4.6% per year.

CYP2C9 inducer that decreases warfarin exposure and INR; requires close INR monitoring.

Vitamin K antagonizes the anticoagulant action of warfarin, requiring prothrombin/INR monitoring and potential dose adjustment.

Aspirin can displace warfarin from protein binding sites, leading to prolongation of prothrombin time and increased bleeding risk.

Aspirin displaces warfarin from protein binding sites, leading to prolongation of prothrombin time and bleeding time.

Aspirin displaces warfarin from protein binding sites, leading to prolongation of prothrombin time and bleeding time.

Proguanil may potentiate the anticoagulant effect of warfarin. Coagulation tests should be closely monitored.

Cases of bleeding and increased INR occurred in clinical trials. Avoid concomitant use; use an alternative anticoagulant if possible. Monitor INR frequently if use is unavoidable.

Coadministration usually results in inhibition of response to warfarin; coagulation indices should be monitored frequently.

Potentiation of anticoagulant effect with prolongation of prothrombin time; closely monitor prothrombin time, INR, and monitor for bleeding.

Co-administration with bivalirudin associated with increased risk of major bleeding events in patients undergoing PCI/PTCA.

CYP2C9 inducer that decreases warfarin exposure and INR; requires close INR monitoring.

Meloxicam and warfarin have synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

CYP2C9 inducer that decreases warfarin exposure and INR; requires close INR monitoring.

Increased prothrombin time, with or without clinical bleeding, has been reported when cefixime is administered concomitantly with warfarin.

Concomitant use increases risk of bleeding complications, including serious and fatal bleeding events reported post-marketing, particularly in elderly patients with increases in prothrombin time.

Ceritinib increased systemic exposure of warfarin, enhancing anti-coagulant effect. Increase INR monitoring frequency if coadministration unavoidable; consider dose reduction.

Cholestyramine may delay or reduce the absorption of warfarin. Discontinuance could pose a hazard if warfarin has been titrated to maintenance level.

Cholestyramine may delay or reduce the absorption of warfarin, which could affect its anticoagulant efficacy.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Cimetidine reduces hepatic metabolism of warfarin, increasing blood levels and delaying elimination. Clinically significant effects reported; close monitoring of prothrombin time and dose adjustment recommended.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Systemic quinolone administration enhances the effects of the oral anticoagulant warfarin and its derivatives.

Altered anticoagulant effects including increased bleeding reported with citalopram and warfarin coadministration. Careful monitoring required when citalopram is initiated or discontinued.

Altered anticoagulant effects and increased bleeding reported. Patients should be carefully monitored when citalopram is initiated or discontinued.

Concomitant administration potentiates anticoagulant effects. Postmarketing reports suggest increased warfarin effect with clarithromycin.

Coadministration increases bleeding risk due to independent effects on hemostasis, despite no pharmacokinetic interaction.

Coadministration increases bleeding risk due to independent effects on hemostasis, despite no pharmacokinetic interaction with S-warfarin or INR.

Colesevelam may decrease warfarin exposure and INR. Monitor INR frequently during initiation and periodically thereafter.

Postmarketing reports of reduced INR in patients receiving warfarin. Frequent INR monitoring required during initiation and periodically thereafter.

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Danazol prolongs prothrombin time in patients stabilized on warfarin, increasing anticoagulant effect.

Altered anticoagulant effects and increased bleeding reported when SNRIs co-administered with warfarin. Careful monitoring required when desvenlafaxine is initiated or discontinued.

Increased INR and prothrombin time may lead to abnormal bleeding and even death. Monitor INR and prothrombin time; dose adjustment may be needed.

Vitamin K1 in soybean oil component may reverse anticoagulant activity of warfarin. Monitor anticoagulant laboratory parameters.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone. Monitor for signs of bleeding.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Concomitant use may increase risk of bleeding. Monitor patients for signs of bleeding.

Synergistic effect on bleeding with diclofenac; concomitant use increases risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Diclofenac and warfarin have synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Concomitant administration of econazole and warfarin results in enhancement of anticoagulation effect. Risk increases with occlusive application, genital use, or large body surface area application.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Coumarin-derived anticoagulant interaction increases INR and bleeding risk, with fatal cases reported. Regularly monitor prothrombin time/INR.

Coumarin-derived anticoagulant interaction can increase INR and cause bleeding, including fatal outcomes. Regularly monitor prothrombin time or INR.

Altered anticoagulant effects including increased bleeding reported. Patients receiving warfarin should be carefully monitored when escitalopram is initiated or discontinued.

Concomitant use may potentiate the risk of bleeding. Carefully monitor international normalized ratio in patients taking warfarin.

Concomitant use increases INR and prothrombin time, potentially leading to abnormal bleeding and death.

Concomitant use increases INR and prothrombin time, potentially leading to abnormal bleeding and death.

Concomitant use may increase INR and prothrombin time, leading to abnormal bleeding and even death.

Increased INR and prothrombin time may lead to abnormal bleeding and even death; monitor INR and adjust warfarin dose to maintain target range.

The effects of warfarin and NSAIDs on GI bleeding are synergistic, resulting in increased risk of serious GI bleeding compared to either drug alone.

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Fenoprofen and warfarin have a synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Elevated coagulation times reported with concurrent use. Fluorouracil or its metabolites may inhibit CYP2C9, increasing warfarin concentrations.

Fluoxetine may potentiate bleeding risk through serotonin reuptake inhibition affecting platelet hemostasis.

Fluoxetine may cause altered anticoagulant effects and increased bleeding; requires careful monitoring when initiating or discontinuing fluoxetine.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Inhibitor of CYP2C9 and CYP1A2 that increases warfarin effect and INR; requires close INR monitoring

Concomitant use may elevate INR and cause hemorrhage. Monitor prothrombin time or INR regularly in patients taking warfarin.

Caution when used together; warfarin dosage should be reduced and prothrombin time monitored to prevent bleeding complications.

GVOKE may increase anticoagulant effect of warfarin. Monitor for unusual bruising or bleeding; warfarin dosage adjustments may be required.

Bleeding has been reported when ibuprofen and warfarin are administered together. Effects on GI bleeding are synergistic, with combined use carrying higher risk of serious GI bleeding than either drug alone.

Ibuprofen and warfarin have synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic risk of serious GI bleeding when used together. Although no significant pharmacokinetic interaction observed, NSAIDs and warfarin together carry higher GI bleeding risk than either drug alone.

Concomitant use may increase INR and prothrombin time, leading to abnormal bleeding and potentially death. Dose adjustment of warfarin may be needed.

Increased INR and prothrombin time may occur with concomitant use, potentially leading to abnormal bleeding and death.

Teriflunomide may decrease peak INR by approximately 25%. Close monitoring of INR is required with concomitant use.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Levofloxacin may enhance warfarin effects, elevating prothrombin time and increasing bleeding risk. Monitor prothrombin time, INR, and watch for bleeding.

Levofloxacin may enhance warfarin effects, elevating prothrombin time and increasing bleeding risk. Monitor INR and prothrombin time closely.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Lomitapide increases plasma concentrations of warfarin by approximately 30% and increases INR by 22%. Monitor INR regularly, especially with dose adjustments.

NSAIDs and warfarin have synergistic effects on GI bleeding, with combined use carrying higher risk of serious GI bleeding than either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Meloxicam and warfarin have synergistic effect on bleeding with increased risk of serious bleeding. Monitor for changes in INR and bleeding complications.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Prolonged anticoagulant effects and prothrombin time prolongation reported with oral metronidazole co-administration.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Women using miconazole intravaginal cream may be at risk for increased prothrombin time, INR, and bleeding when taking warfarin anticoagulant.

Fluoroquinolones enhance anticoagulant effects of warfarin. Monitor prothrombin time/INR and bleeding closely.

Enhanced anticoagulant effect. Monitor prothrombin time/INR and bleeding closely.

Moxifloxacin enhances anticoagulant effects of warfarin. Monitor prothrombin time/INR and bleeding closely during concomitant use.

Vitamin K in the product antagonizes warfarin's anticoagulant action. Prothrombin/INR monitoring and warfarin dose adjustment may be needed.

The effects of warfarin and NSAIDs on GI bleeding are synergistic, resulting in serious GI bleeding risk higher than either drug alone. Caution should be exercised with nabumetone and warfarin.

Nafcillin in high doses (2g every 4 hours) decreases warfarin effects. Effect may persist up to 30 days after nafcillin discontinuation.

Nafcillin in high doses (2 grams every 4 hours) decreases warfarin effects. Prothrombin time requires close monitoring and warfarin dose adjustment. Effect may persist up to 30 days after nafcillin discontinuation.

Naproxen and warfarin have synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Naproxen and warfarin have synergistic effect on bleeding with increased risk of serious bleeding. Esomeprazole increases INR and prothrombin time with warfarin, potentially leading to abnormal bleeding and death.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Plasma warfarin levels may change with potential for increases in coagulation time. Anticoagulation levels should be monitored frequently.

Nitisinone inhibits CYP2C9, significantly increasing warfarin exposure. Reduce dosage by half and adjust to maintain therapeutic drug concentrations due to narrow therapeutic index.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Quinolones including ofloxacin have been reported to enhance the effects of oral anticoagulant warfarin or its derivatives, increasing anticoagulation risk.

Systemic quinolone administration enhances the effects of oral anticoagulant warfarin and its derivatives.

Increased INR and prothrombin time in patients receiving omeprazole and warfarin concomitantly, which may lead to abnormal bleeding and death.

Increased INR and prothrombin time may lead to abnormal bleeding and death; monitor INR and prothrombin time and adjust warfarin dose as needed.

Concomitant use may increase INR and prothrombin time, leading to abnormal bleeding and potentially death. Monitor INR and adjust warfarin dose as needed.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Decreased prothrombin, increased INR, and unbalanced anticoagulant treatment reported. Close monitoring of coagulation parameters required.

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Aspirin displaces warfarin from protein binding, prolonging prothrombin time and bleeding time, increasing bleeding risk.

Concomitant use of pantoprazole and warfarin may increase INR and prothrombin time, leading to abnormal bleeding and potentially death.

Increased INR and prothrombin time may lead to abnormal bleeding and even death. Monitor INR and prothrombin time; warfarin dose adjustment may be needed.

Increased INR and prothrombin time in patients receiving pantoprazole and warfarin concomitantly, which may lead to abnormal bleeding and death.

Increased INR and prothrombin time may occur, potentially leading to abnormal bleeding and death. Monitor INR and dose adjustment may be needed.

Increased INR and prothrombin time in patients receiving pantoprazole and warfarin concomitantly, which may lead to abnormal bleeding and death.

Concurrent use of warfarin with paroxetine may potentiate the risk of bleeding and increase warfarin plasma concentration. Monitor INR carefully.

Increased plasma concentrations due to protein binding and CYP2D6 inhibition; increased bleeding risk. Monitor INR carefully and reduce dosage as warranted.

Monitor for adverse reactions and reduce dosage as warranted. Increased risk of bleeding when used with anticoagulants.

CYP2C9 inducer that decreases warfarin exposure and INR; requires close INR monitoring.

Barbiturates induce hepatic microsomal enzymes resulting in increased metabolism and decreased anticoagulant response of warfarin. Dosage adjustments may be required.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Coadministration increases the risk of bleeding.

Coadministration of prasugrel and warfarin increases the risk of bleeding.

Can produce significant impairment in folate status after 6-month therapy; caution should be exercised.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Propafenone may increase warfarin levels, requiring monitoring.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Quinidine potentiates warfarin's anticoagulatory action; anticoagulant dosage may need reduction.

Quinidine potentiates anticoagulatory action of warfarin; anticoagulant dosage may need reduction.

Concomitant use may increase INR and prothrombin time, potentially leading to abnormal bleeding and death.

Concomitant use may increase INR and prothrombin time, leading to abnormal bleeding and potentially death.

CYP2C9 inducer that decreases warfarin exposure and INR; requires close INR monitoring.

The effects of warfarin and NSAIDs on GI bleeding are synergistic, resulting in a higher risk of serious GI bleeding than either drug alone.

Concurrent use may potentiate bleeding risk. Monitor international normalized ratio carefully.

Concurrent use may potentiate bleeding risk and increase warfarin plasma concentrations.

BACTRIM may prolong prothrombin time in patients receiving warfarin. Sulfamethoxazole inhibits CYP2C9, increasing warfarin levels.

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Synergistic effect on bleeding with increased risk of serious bleeding compared to either drug alone.

Marked increase in anticoagulant effect may occur. Closely monitor coagulation indices in patients taking tamoxifen for metastatic breast cancer or adjuvant therapy.

CYP1A2 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Teriflunomide may decrease peak INR by approximately 25%. Close monitoring of INR is required.

CYP1A2 inhibitor that increases warfarin exposure and INR effect; requires close INR monitoring.

CYP1A2 inhibitor that increases warfarin exposure and INR effect; requires close INR monitoring.

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Tinidazole may enhance the effect of warfarin, resulting in prolongation of prothrombin time. Anticoagulant dosage may need adjustment during and up to 8 days after tinidazole therapy.

NSAIDs and warfarin have synergistic effects on GI bleeding, increasing risk of serious GI bleeding. Increased prothrombin time and bleeding have been reported with concomitant use. Caution is advised.

Torsemide may affect warfarin efficacy and safety as a CYP2C9 substrate with narrow therapeutic range; requires monitoring and possible dose adjustment.

Increased risk of bleeding due to serotonin effects on platelet hemostasis. Monitor INR when initiating or discontinuing trazodone.

Concomitant use increases warfarin Cmax and AUC, which may increase the risk of bleeding. Monitor INR more frequently.

Altered anticoagulant effects including increased bleeding. Patients should be carefully monitored when venlafaxine is initiated or discontinued.

Bromelain may increase the risk of bleeding when combined with warfarin.

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

CYP2C9 inhibitor that increases warfarin effect and INR; requires close INR monitoring

Zileuton decreases R-warfarin clearance by 15% and increases AUC by 22%, resulting in clinically significant increases in prothrombin times. Monitor prothrombin time and adjust warfarin dose accordingly.

Monitoring of effect recommended upon initiation or discontinuation of HUMIRA; dose adjustment may be needed.

ADALIMUMAB-AACF may influence CYP450 enzyme formation, affecting warfarin metabolism. Monitoring of warfarin effect is recommended upon initiation or discontinuation of ADALIMUMAB-AACF.

Adalimumab may influence CYP450 enzyme formation. Monitoring of warfarin effect and dose adjustment recommended.

Adalimumab-adaz may suppress CYP450 enzyme formation, potentially affecting warfarin metabolism. Monitoring and dose adjustment recommended.

CYP450 enzyme formation may be suppressed by adalimumab-adbm. Monitoring of warfarin effect recommended upon initiation or discontinuation.

Adalimumab may influence CYP450 enzyme formation, affecting warfarin metabolism. Monitoring of effect and dose adjustment recommended.

YUSIMRY may suppress CYP450 enzyme formation; monitor warfarin effect and adjust dose as needed upon initiation or discontinuation.

AMJEVITA may influence CYP450 enzyme formation; monitoring of warfarin effect and dose adjustment recommended.

HADLIMA may influence CYP450 enzyme formation; monitoring of warfarin effect recommended with dose adjustment as needed.

Adalimumab-fkjp may influence CYP450 enzyme formation; monitoring of warfarin effect recommended with dose adjustment as needed.

Adalimumab-ryvk may suppress CYP450 enzyme formation, affecting warfarin metabolism. Monitor effect and adjust dose as needed.

Concomitant use results in increased prolongation of PT and INR. Monitor PT/INR closely during combined therapy.

More frequent monitoring of prothrombin times/INR should be considered whenever armodafinil is coadministered with warfarin.

Interaction with warfarin noted. Continue standard monitoring.

Azathioprine may inhibit the anticoagulant effect of warfarin.

Concomitant administration may potentiate effects of oral anticoagulants. Prothrombin times should be carefully monitored.

Concomitant administration may potentiate anticoagulant effects. Prothrombin times should be carefully monitored.

Concomitant administration may potentiate anticoagulant effects. Prothrombin times should be carefully monitored during concurrent use.

BIMKELX may modulate serum cytokine levels, altering CYP450 enzyme formation and affecting warfarin metabolism. Monitor for effect upon initiation or discontinuation.

BLINATUMOMAB causes transient cytokine release that may suppress CYP450 enzymes, increasing warfarin levels. Monitor for toxicity during first 9 days of first cycle and first 2 days of second cycle.

SILIQ may modulate serum levels of cytokines affecting CYP450 enzyme formation, potentially altering warfarin metabolism. Monitor for effect upon initiation or discontinuation of SILIQ.

Canakinumab may normalize CYP450 enzyme formation, potentially affecting warfarin metabolism. Therapeutic monitoring and dose adjustment may be needed.

Rare reports of increased prothrombin time with or without clinical bleeding in patients receiving cefaclor and warfarin concomitantly.

Cholestyramine may delay or reduce absorption of warfarin.

Increased anticoagulant effect and INR elevation may occur. Monitor prothrombin time and INR frequently during and after co-administration.

Both increased and decreased warfarin effect have been reported in patients receiving warfarin and cyclophosphamide. Anticoagulant activity should be monitored closely.

Both increased and decreased warfarin effect have been reported. Monitor anticoagulant activity closely.

Both increased and decreased warfarin effects reported in patients receiving concomitant cyclophosphamide.

Dabrafenib decreased systemic exposure of S-warfarin (CYP2C9 substrate). Monitor INR levels more frequently during initiation or discontinuation of dabrafenib.

Warfarin reduces binding of dantrolene to plasma proteins, potentially increasing free drug concentration.

Warfarin reduces dantrolene binding to plasma proteins, potentially affecting dantrolene levels and efficacy.

Dasiglucagon may increase the anticoagulant effect of warfarin.

Co-administration usually results in inhibition of warfarin response; coagulation indices should be monitored frequently.

Concomitant use may potentiate risk of bleeding. Closely monitor for bleeding when desvenlafaxine is initiated or discontinued.

Concomitant use may potentiate bleeding risk. Closely monitor for bleeding when desvenlafaxine is initiated or discontinued.

Dexamethasone usually inhibits response to warfarin; coagulation indices should be monitored frequently.

Dexamethasone usually inhibits response to warfarin; coagulation indices should be monitored frequently.

Dexamethasone usually inhibits response to warfarin; coagulation indices should be monitored frequently.

CYP3A4 substrate; diazepam may interfere with its metabolism, leading to potential drug-drug interaction.

Dicloxacillin may reduce the anticoagulant response to warfarin; careful monitoring of prothrombin times is suggested and dosage adjustment may be needed.

Dosage adjustment of warfarin may be necessary when used concomitantly with divalproex sodium delayed-release tablets.

Highly protein-bound drug with narrow therapeutic index; dronabinol may displace warfarin from plasma proteins increasing free fraction. Monitor for adverse reactions.

Monitor INR after initiating dronedarone in patients taking warfarin.

TRULICITY delays gastric emptying and may reduce absorption rate of warfarin. Monitor drug levels of oral medications with narrow therapeutic index when concomitantly administered.

Monitor carefully when initiating or discontinuing duloxetine. Altered anticoagulant effects and increased bleeding reported with SNRIs; however, duloxetine did not significantly affect INR or warfarin pharmacokinetics in clinical study.

Duloxetine may potentiate bleeding risk; careful monitoring recommended when initiating or discontinuing duloxetine in patients on warfarin therapy.

Potential effect on platelets; patients should be carefully monitored when duloxetine is initiated or discontinued despite no significant INR changes observed in clinical studies.

Limited in vitro and in vivo studies are inconclusive regarding interaction with tamsulosin component. Caution should be exercised with concomitant administration.

Clearance of HCV infection may lead to changes in hepatic function affecting warfarin metabolism. Frequent monitoring of INR and dose adjustments may be necessary.

Ivacaftor may inhibit CYP2C9, potentially increasing warfarin exposure. Monitoring of INR during concomitant use is recommended.

Entacapone may increase R-warfarin AUC by 18% and INR values by 13% on average. Cases of significantly increased INR have been reported during postapproval use.

Increased anticoagulant effects may occur, potentially more pronounced in elderly patients.

Ethacrynate sodium may displace warfarin from plasma protein binding, potentially increasing anticoagulant effect. Reduction in warfarin dosage may be required.

Ethacrynic acid may displace warfarin from plasma protein binding; reduction in anticoagulant dosage may be required.

Co-administration of etoposide with warfarin can result in elevated international normalized ratio (INR). Monitor INR more frequently and modify warfarin dosage as appropriate.

Co-administration of ETOPOPHOS with warfarin can result in elevated international normalized ratio (INR). Measure INR frequently.

Post-marketing reports of increased INR with exenatide use, sometimes associated with bleeding. Monitor prothrombin time more frequently after initiation or alteration of exenatide therapy.

If ezetimibe is added to warfarin (a coumarin anticoagulant), the International Normalized Ratio (INR) should be appropriately monitored.

Flutamide increases prothrombin time in patients receiving long-term warfarin therapy. Close monitoring of prothrombin time is recommended and anticoagulant dose adjustment may be necessary.

Monitor INR before starting and frequently after fluvastatin initiation or discontinuation to ensure no significant alteration in INR occurs.

Potential interaction due to fluvoxamine inhibition of CYP1A2 and CYP2C9, which are involved in warfarin metabolism.

Concomitant use did not significantly affect pharmacokinetics/pharmacodynamics in clinical studies. Monitor patients closely for hemorrhage if co-administration is necessary.

May increase phenytoin serum levels; monitoring of phenytoin levels recommended.

Clearance of HCV infection may alter hepatic function and impact INR. Frequent monitoring of INR and dose adjustments may be necessary.

Coumarin anticoagulant that may increase glucose-lowering effect of glimepiride, increasing susceptibility to hypoglycemia.

Glucagon may increase the anticoagulant effect of warfarin. Monitor patients for unusual bruising or bleeding; warfarin dosage adjustments may be required.

Golimumab may normalize CYP450 enzyme formation, potentially affecting warfarin metabolism. Monitoring and dose adjustment recommended.

May increase risk of bleeding or increased INR. Monitor INR and for clinical bleeding episodes.

Griseofulvin decreases the activity of warfarin-type anticoagulants, requiring dosage adjustment of the anticoagulant during and after griseofulvin therapy.

Corticosteroids usually inhibit warfarin response; monitor coagulation indices to maintain anticoagulant effect.

Corticosteroids inhibit warfarin response; coagulation indices should be monitored.

Coadministration usually results in inhibition of response to warfarin. Coagulation indices should be monitored frequently.

Soybean oil in I.V. Fat Emulsion contains vitamin K1 which may counteract the anticoagulant activity of warfarin. Increase monitoring of coagulation parameters.

Bleeding has been reported when ibuprofen and other NSAIDs are administered to patients on warfarin-type anticoagulants. Monitor for bleeding signs.

Monitoring of effect recommended upon initiation or discontinuation of infliximab; individual dose adjustment may be needed.

Monitoring of anticoagulant effect recommended upon initiation or discontinuation of AVSOLA due to potential normalization of CYP450 enzyme formation.

TNF blocker may normalize CYP450 enzyme formation, potentially decreasing warfarin exposure. Monitor INR and adjust dosage as needed upon initiation or discontinuation.

Ivacaftor may inhibit CYP2C9, potentially increasing warfarin exposure. INR monitoring recommended during concomitant use.

Post-marketing reports of increased INR have been rarely reported when ivermectin was co-administered with warfarin.

Co-administration usually results in inhibition of warfarin response; coagulation indices should be monitored frequently.

No effect on pharmacokinetics of lenalidomide or warfarin, but close monitoring of PT and INR is recommended in patients taking concomitant warfarin.

Reports of INR increase have been observed with levocarnitine use. INR levels should be monitored in patients on warfarin therapy after initiation or dose adjustments of levocarnitine.

Anticoagulant that may potentiate bleeding risk when used with levomilnacipran. Closely monitor for bleeding.

Coumarin anticoagulant; bleeding and increased prothrombin time reported with lovastatin. Requires monitoring.

Co-administration of corticosteroids and warfarin usually results in inhibition of response to warfarin. Coagulation indices should be monitored frequently.

Megestrol acetate may interact with warfarin and increase International Normalized Ratio (INR). Closely monitor INR in patients taking both drugs.

Mercaptopurine may decrease anticoagulant effectiveness of warfarin. Monitor INR and adjust warfarin dosage as appropriate.

Methylene blue inhibits CYP2C9 metabolism. Warfarin has narrow therapeutic index; clinical relevance unknown but concurrent use requires caution.

Methimazole may inhibit vitamin K activity, increasing warfarin activity. Additional monitoring of PT/INR is recommended, especially before surgical procedures.

Co-administration usually results in inhibition of response to warfarin. Coagulation indices should be monitored frequently to maintain desired anticoagulant effect.

Co-administration usually results in inhibition of warfarin response. Coagulation indices should be monitored frequently.

Co-administration usually results in inhibition of warfarin response. Coagulation indices should be monitored frequently.

Coadministration of corticosteroids and warfarin usually results in inhibition of response to warfarin; coagulation indices should be monitored.

Metreleptin may alter CYP450 metabolism of warfarin. Therapeutic monitoring of effect recommended upon initiation or discontinuation of metreleptin.

Mirabegron increases warfarin Cmax (~4%) and AUC (~9%). Effect on multiple-dose warfarin pharmacodynamics (INR, prothrombin time) not fully investigated; monitoring recommended.

Monitor INR during concomitant use with mirtazapine.

More frequent monitoring of prothrombin times/INR should be considered whenever modafinil is coadministered with warfarin.

Nefazodone decreased S-warfarin exposure by 12%, but no effects on prothrombin or bleeding times. Monitoring recommended per standard medical practice.

Monitor INR and adjust warfarin dosage as needed with concomitant use of AKYNZEO to maintain target INR range.

Competition for plasma protein binding sites may occur when nitazoxanide is administered concurrently with warfarin. Monitor for adverse reactions due to potential displacement from binding sites.

May potentiate the risk of bleeding when used with drugs that interfere with hemostasis.

Olive and soybean oils contain natural Vitamin K1 that may counteract the anticoagulant activity of warfarin, potentially reducing its effectiveness.

ORBACTIV may affect warfarin concentrations as it inhibits CYP2C9. Patients should be monitored for bleeding signs; however, a drug-drug interaction study showed no effect on S-warfarin Cmax or AUC.

Oritavancin is a weak CYP2C9 inhibitor. Although a study showed no effect on S-warfarin pharmacokinetics, patients should be monitored closely for bleeding when concomitantly receiving oritavancin and warfarin.

Single dose warfarin pharmacokinetics unaffected by ospemifene, but effect on clotting time (INR/PT) and multiple-dose warfarin not studied. Monitor accordingly.

Barbiturates induce hepatic microsomal enzymes, increasing metabolism and decreasing anticoagulant response. Dosage adjustments may be needed.

Pentosan polysulfate sodium does not significantly alter warfarin pharmacokinetics or INR values, but use with caution in patients receiving anticoagulant therapies.

May increase phenytoin serum levels; monitoring of phenytoin levels recommended.

May increase phenytoin serum levels; monitoring of phenytoin levels recommended.

Corticosteroids usually inhibit response to warfarin; coagulation indices should be monitored frequently to maintain anticoagulant effect.

Corticosteroids usually inhibit warfarin response, although conflicting reports exist. Coagulation indices should be monitored frequently.

Warfarin concentrations are increased when administered with propranolol. Monitor prothrombin time accordingly.

Propylthiouracil may inhibit vitamin K activity and increase oral anticoagulant activity. Additional monitoring of PT/INR is recommended, especially before surgical procedures.

PURIXAN may decrease the anticoagulant effect of warfarin.

Monitor prothrombin time when starting or stopping raloxifene; may affect warfarin efficacy.

Monitor prothrombin time when starting or stopping raloxifene hydrochloride due to potential interaction.

Reports of altered prothrombin time during concurrent ranitidine and warfarin therapy. Close monitoring of prothrombin time is recommended due to warfarin's narrow therapeutic index.

Ranitidine may alter prothrombin time in patients on concurrent warfarin therapy. Close monitoring of prothrombin time is recommended during concurrent treatment.

Rifapentine may increase metabolism and decrease activity. Dosage adjustment may be necessary.

Changes in INR reported postmarketing. Monitor INR and prothrombin time; dose adjustment of warfarin may be needed to maintain target INR range.

Rilonacept may normalize CYP450 enzyme formation, affecting warfarin metabolism. Therapeutic monitoring and dose adjustment may be needed.

Prolongation of PT and elevation of INR observed. Monitor PT and INR more frequently when co-administered with romidepsin.

Rosuvastatin may increase warfarin effects. Monitor INR frequently upon initiation, dose titration, or discontinuation of rosuvastatin.

Rosuvastatin may affect warfarin anticoagulant effect. Monitor INR frequently until stable upon initiation, dose titration, or discontinuation.

Concomitant administration with rucaparib can increase systemic exposure of warfarin, potentially increasing frequency or severity of adverse reactions. Consider increasing frequency of INR monitoring if concomitant use cannot be avoided.

Sarilumab may alter warfarin concentrations through CYP modulation; therapeutic monitoring and dose adjustment recommended upon initiation or discontinuation.

SILTUXIMAB may restore CYP450 activities leading to increased metabolism of warfarin. Therapeutic monitoring and dose adjustment recommended upon initiation or discontinuation.

Coumarin anticoagulant. Obtain INR before simvastatin initiation and monitor INR during simvastatin dosage initiation or adjustment.

Soybean oil contains vitamin K1 which can reverse the anticoagulant activity of warfarin. Monitor laboratory parameters for anticoagulant activity.

Subtherapeutic prothrombin times reported with concomitant warfarin and sucralfate; however, clinical studies showed no change in warfarin concentration or prothrombin time. Monitor prothrombin time appropriately.

Spontaneous reports of increased or decreased prothrombin times with concomitant oral terbinafine and warfarin, though causal relationship not established.

Androgens may alter anticoagulant activity; more frequent monitoring of INR and prothrombin time is recommended, especially at initiation and termination of therapy.

Androgens may alter anticoagulant activity; more frequent monitoring of INR and prothrombin time recommended.

Concomitant use may cause changes in anticoagulant activity. More frequent monitoring of INR and prothrombin time is recommended, especially at initiation and termination of androgen therapy.

MOUNJARO delays gastric emptying and may impact absorption; monitor patients on narrow therapeutic index drugs.

Tocilizumab may affect warfarin metabolism; therapeutic monitoring of effect recommended upon initiation or discontinuation.

Tocilizumab may affect warfarin metabolism; perform therapeutic monitoring and adjust dose as needed upon initiation or discontinuation.

Tolcapone has affinity for CYP450 2C9 in vitro and may interfere with warfarin clearance. Clinical information is limited; coagulation parameters should be monitored when co-administered.

CYP2C9 substrate with narrow therapeutic index; use with caution and require careful monitoring.

Corticosteroids usually inhibit response to warfarin; coagulation indices should be monitored frequently.

Coadministration usually results in inhibition of response to warfarin; monitor coagulation indices frequently.

Dosage adjustment of warfarin may be necessary if used concomitantly with valproate due to altered pharmacokinetics.

Dosage adjustment may be necessary if used concomitantly with valproic acid.

Smoking cessation with varenicline may alter warfarin pharmacokinetics or pharmacodynamics, necessitating dose adjustment.

Smoking cessation may alter pharmacokinetics or pharmacodynamics, necessitating dose adjustment.

Frequent monitoring of INR and dose adjustments may be necessary due to HCV clearance-related changes in hepatic function.

Altered anticoagulant effects and increased bleeding risk reported; patients should be carefully monitored when venlafaxine is initiated or discontinued.

Anticoagulant that may have potentiated bleeding risk; carefully monitor INR when initiating, titrating, or discontinuing vilazodone.

Anticoagulant may potentiate risk of bleeding with vortioxetine. Carefully monitor international normalized ratio.

Chronic ingestion of large acetaminophen doses may slightly potentiate warfarin effects.

Anastrozole did not alter the exposure or anticoagulant activity of warfarin in a study of 16 male volunteers.

Anastrozole did not alter the exposure or anticoagulant activity of R- and S-warfarin in a study of 16 male volunteers.

Interaction studies failed to identify clinically important effects on serum concentrations or clinical effects of warfarin.

No clinically important effects of benazepril on serum concentrations or clinical effects identified in interaction studies.

No effect of bisoprolol fumarate on prothrombin time in patients on stable doses of warfarin.

Interaction studies in humans have shown bumetanide has no effect on warfarin metabolism or plasma prothrombin activity.

Darifenacin had no significant effect on prothrombin time; standard therapeutic monitoring should be continued.

Darifenacin had no significant effect on prothrombin time. Standard monitoring should continue.

In vitro data indicate doxazosin has no effect on protein binding of warfarin.

Concomitant administration does not alter steady-state pharmacokinetics of S- or R-warfarin isomers or alter the effect on prothrombin time.

No clinically meaningful interaction identified in testing.

In clinical studies, concomitant irbesartan had negligible consequences on the pharmacodynamics of warfarin (prothrombin time).

No clinically relevant pharmacokinetic or pharmacodynamic interaction observed between isradipine and racemic warfarin; plasma protein binding not altered.

Interaction study showed no clinically significant effect of letrozole on warfarin pharmacokinetics.

Interaction study showed no clinically significant effect of letrozole on warfarin pharmacokinetics.

Levetiracetam did not influence R and S warfarin pharmacokinetics or prothrombin time.

Losartan did not affect the pharmacokinetics or pharmacodynamics of warfarin.

Losartan did not affect the pharmacokinetics or pharmacodynamics of warfarin. No significant drug-drug pharmacokinetic interaction found.

No effect of miglitol was observed on the pharmacokinetics or pharmacodynamics of warfarin.

Interaction studies failed to identify any clinically important effect on serum concentrations or anticoagulant effect of warfarin.

No dose adjustment needed when co-administered with montelukast sodium.

No dose adjustment needed when co-administered with montelukast sodium.

Warfarin does not affect olanzapine pharmacokinetics.

Warfarin does not affect olanzapine pharmacokinetics.

No significant drug interactions reported when co-administered with olmesartan medoxomil in healthy volunteers.

Pravastatin 40 mg had no clinically significant effect on warfarin prothrombin time.

Single dose anticoagulant effect of warfarin (measured by prothrombin time) was not significantly affected by quinapril.

Telmisartan slightly decreased mean warfarin trough plasma concentration, but this did not result in a change in INR.

No significant differences observed in steady-state pharmacokinetics of R-warfarin or S-warfarin with tiagabine. Prothrombin times were not affected.

No clinically significant effect on treprostinil pharmacokinetics or warfarin pharmacokinetics/pharmacodynamics; INR unaffected.

Coadministration of valsartan and warfarin did not change the pharmacokinetics of valsartan or the time-course of warfarin's anticoagulant properties.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.

Spontaneous reports of increase or decrease in prothrombin times with concomitant use, but causal relationship not established.

No significant pharmacokinetic interaction observed between warfarin and thalidomide in a single-dose study, but clinical significance unclear.

Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3.