Cimetidine

CYP450 inhibitor that increases amiodarone exposure. Avoid concomitant use.

Cimetidine 400 mg BID increases dofetilide plasma levels by 58%. Concomitant use is contraindicated.

Potent CYP1A2 inhibitor; should be avoided due to significant increase in duloxetine concentrations.

Can inhibit metabolism of chloroquine, increasing plasma level; concomitant use should be avoided.

Avoid coadministration of cimetidine with posaconazole unless the benefit outweighs the risks.

May increase metformin accumulation and risk of lactic acidosis by reducing metformin clearance through OCT2/MATE inhibition.

Cimetidine inhibits cytochrome P450 2D6, potentially causing toxic amitriptyline levels in normal metabolizers; may require lower amitriptyline doses.

Greater myelosuppression (leukopenia, neutropenia) reported with concomitant use. Consider alternative drugs.

Cimetidine inhibits metabolism of chloroquine, increasing plasma levels. Concomitant use should be avoided.

Cimetidine increases citalopram AUC by 43% and Cmax by 39%. Maximum citalopram dose 20 mg/day recommended with concurrent cimetidine due to QT prolongation risk.

Combined administration increases citalopram AUC by 43% and Cmax by 39%, increasing QT prolongation risk. Maximum recommended citalopram dose is 20 mg/day with cimetidine.

OCT2 inhibitor; concurrent use may increase dalfampridine exposure and elevate seizure risk.

OCT2/MATE inhibitor that increases metformin exposure and may increase risk for lactic acidosis.

Inhibits cytochrome P450 2D6, may increase desipramine plasma concentrations and risk of toxicity; dose adjustment may be necessary.

Inhibits hepatic enzymes (CYP3A and 2C19), leading to increased and prolonged sedation.

Cimetidine doubles doxepin exposure by inhibiting CYP isozymes. Maximum dose of 3 mg recommended when co-administered.

Cimetidine increases doxepin exposure by doubling plasma concentrations. Maximum dose of 3 mg recommended when co-administered.

Potent CYP1A2 inhibitor that should be avoided due to potential significant increase in duloxetine concentrations.

Cimetidine inhibits metformin clearance via OCT2/MATE, increasing metformin exposure and risk of lactic acidosis.

OCT2/MATE inhibitor that interferes with renal elimination of metformin, increasing systemic exposure and risk of lactic acidosis.

OCT2/MATE inhibitor that may increase systemic metformin exposure and increase risk for lactic acidosis.

Cimetidine increases systemic exposure to epirubicin. Discontinue cimetidine during ELLENCE treatment.

Increases risk of lactic acidosis by reducing metformin clearance through OCT2/MATE inhibition.

Reduces metformin clearance and may increase risk for lactic acidosis.

Cimetidine causes 2-fold increase in chloroquine exposure; concomitant use should be avoided.

Inhibits cytochrome P450 2D6 and hepatic enzymes, reducing imipramine metabolism and increasing plasma concentrations. Dose adjustment may be necessary.

Cimetidine reduces hepatic metabolism of lidocaine, delaying elimination and increasing blood levels. Adverse clinical effects have been reported.

Coadministration may reduce clearance of lidocaine from plasma and result in toxic accumulation of the drug.

OCT2/MATE inhibitor that reduces metformin clearance, increasing systemic exposure and risk of lactic acidosis.

Reduces metformin clearance by inhibiting renal tubular transport, increasing systemic exposure and lactic acidosis risk.

Reduces metformin clearance, increasing systemic exposure and risk of lactic acidosis.

OCT2/MATE inhibitor that reduces metformin clearance and may increase risk of lactic acidosis through increased systemic metformin exposure.

Reduces metformin clearance, increasing systemic exposure and risk for lactic acidosis.

Reduces metformin clearance via OCT2/MATE inhibition, increasing systemic exposure and risk of lactic acidosis.

Concomitant use has been reported to precipitate apnea and confusion.

Significantly increases peak nifedipine plasma levels (80%) and AUC (74%). Cautious titration advised when initiating nifedipine in patients receiving cimetidine.

Concurrent administration with tricyclic antidepressants can produce clinically significant increases in plasma concentrations of the tricyclic antidepressant.

Cimetidine inhibits cytochrome P450 2D6, potentially causing toxic amitriptyline concentrations; dose reduction may be necessary.

Cimetidine reduces hepatic metabolism of phenytoin, delaying elimination and increasing blood levels. Adverse clinical effects have been reported.

Reduces metformin clearance, increasing systemic exposure and risk for lactic acidosis. Consider benefits and risks of concomitant use.

Avoid coadministration unless benefit outweighs risks. Cimetidine may affect posaconazole plasma concentrations.

Cimetidine reduces hepatic metabolism of protriptyline, increasing steady-state concentrations, plasma levels, and frequency/severity of side effects, particularly anticholinergic effects.

CYP3A4 and CYP1A2 inhibitor that increases roflumilast systemic exposure and may result in increased adverse reactions.

OCT2/MATE inhibitor that reduces metformin clearance, increasing systemic exposure and risk for lactic acidosis.

Reduces metformin clearance via renal tubular transport inhibition, increasing systemic metformin exposure and lactic acidosis risk.

Cimetidine reduces hepatic metabolism of theophylline, increasing blood levels. Adverse clinical effects reported. Alteration less pronounced with 800 mg bedtime dosing. Appropriate monitoring recommended.

CYP1A2 inhibitor; concomitant use should be avoided due to potential for hypotension, bradycardia, or excessive drowsiness.

Concomitant use should be avoided due to potential interactions. If clinically necessary, initiate with 2 mg and titrate cautiously.

Should be avoided due to CYP1A2 inhibition. If necessary, initiate tizanidine at 2 mg and titrate cautiously; monitor for hypotension, bradycardia, or excessive drowsiness.

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

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

Cimetidine doubles the half-life and AUC of zolmitriptan; maximum single dose must be limited to 2.5 mg, not exceeding 5 mg in 24 hours.

Cimetidine increased albendazole sulfoxide concentrations in bile and cystic fluid by about 2-fold in hydatid cyst patients.

Cimetidine may increase the catabolism of cholecalciferol. Additional vitamin D supplementation should be considered.

Moderate CYP1A2 inhibitor; should be avoided unless clinically necessary due to similar potential drug interactions as strong inhibitors.

Moderate CYP1A2 inhibitor. Concomitant administration with alosetron should be avoided unless clinically necessary due to potential drug interactions.

Weak CYP3A inhibitor may increase alprazolam concentrations; avoid use or consider dose reduction.

Weak CYP3A inhibitor may increase alprazolam concentrations. Avoid use and consider dose reduction.

Cimetidine inhibits theophylline clearance, resulting in increased serum theophylline concentrations requiring dose reduction.

Serum levels of tricyclic antidepressants have been significantly increased when cimetidine is administered concurrently; interaction not yet reported with amoxapine but should be considered.

Cimetidine increased AUC and Cmax of threohydrobupropion and erythrohydrobupropion metabolites by 16% and 32%, respectively, but did not affect bupropion and hydroxybupropion pharmacokinetics.

Decreases caffeine elimination; lower caffeine doses may be needed when coadministered.

OCT2/MATE inhibitor that reduces metformin clearance and may increase risk for lactic acidosis. Consider benefits and risks of concomitant use.

CYP3A4 inhibitor that increases carbamazepine plasma levels. Close monitoring of carbamazepine levels and dosage adjustment may be required.

Hepatic metabolism inhibitor that increases carvedilol AUC by approximately 30% with no change in Cmax.

Cimetidine reduces hepatic metabolism of chlordiazepoxide, delaying elimination and increasing blood levels. Dosage adjustment may be necessary.

Cimetidine increases plasma levels of clomipramine through cytochrome P450 2D6 inhibition.

Cimetidine may increase plasma levels of clomipramine; close supervision and dosage adjustment recommended.

CYP2D6 or CYP3A4 inhibitor that can increase clozapine levels and lead to adverse reactions. Close monitoring and dose reduction may be necessary.

May potentiate renal dysfunction when used concomitantly with cyclosporine. Close monitoring of renal function required.

Co-administration resulted in increased plasma concentrations of desloratadine and 3-hydroxydesloratadine, but no clinically relevant changes in safety profile.

Cimetidine significantly increases peak diltiazem plasma levels by approximately 58% and increases AUC.

Cimetidine increases doxazosin AUC by 10%. Clinical significance of this increase is unknown; monitor for increased effects.

CYP1A2 inhibitor that may increase duloxetine concentrations.

Moderate inhibitor resulting in 44% increase in tamsulosin AUC. Use with caution when coadministered.

Combined administration resulted in 43% increase in citalopram AUC and 39% increase in Cmax. Clinical significance unknown.

Increases citalopram AUC by 43% and Cmax by 39%; clinical significance unknown.

Significant CYP3A inhibitor; estazolam should be used with caution and appropriate dosage reduction may be needed.

Non-specific CYP-450 inhibitor resulting in approximately 50% increase in AUC and Cmax of felodipine.

Cimetidine (1 gm daily) increases plasma flecainide levels by ~30% and increases half-life by ~10%.

Weak CYP3A4 inhibitor; concomitant use of multiple weak inhibitors may increase risk of adverse reactions.

Cimetidine 400 mg decreased fluconazole AUC by 13% and Cmax by 19%. Intravenous cimetidine 600-900 mg had no effect on fluconazole bioavailability.

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

Reduces metformin clearance and may increase risk for lactic acidosis.

Inhibits P450 2D6 and hepatic enzymes, increasing imipramine plasma concentrations. May require dose adjustment and TCA level monitoring.

Cimetidine increases isradipine mean peak plasma concentrations by 36% and AUC by 50%. Careful monitoring and downward dose adjustment may be required.

Cimetidine may alter gastric pH and affect ketoconazole absorption. Ketoconazole should be given at least 2 hours before cimetidine administration.

Cimetidine increases labetalol bioavailability, requiring special care in dose adjustment for blood pressure control.

Cimetidine increases bioavailability of labetalol; special care needed in establishing required dose for blood pressure control.

Exposure to cimetidine may be increased when coadministered with leflunomide. Monitor and adjust dose as required.

Exposure of cimetidine may be increased in patients taking leflunomide. Monitor and adjust dose as required.

Concomitant use may reduce hepatic blood flow and lidocaine clearance, increasing incidence of adverse reactions including seizures.

Coadministration led to an increase of about 18% in AUC of losartan but did not affect the pharmacokinetics of its active metabolite.

Potent CYP2D6 inhibitor may increase plasma concentration of metoprolol; caution should be exercised.

Cimetidine decreases microsomal liver enzyme activity, prolonging half-life and decreasing plasma clearance of metronidazole.

May prolong metronidazole half-life and decrease plasma clearance; no dose adjustment of metronidazole vaginal gel necessary.

Reported to increase, decrease, or leave unchanged mexiletine plasma levels; careful patient monitoring required.

Inhibits P450-3A4 enzyme system, increasing midazolam steady-state concentration and prolonging sedation by decreasing plasma clearance.

Inhibits P450-3A4 enzyme system, decreasing plasma clearance of midazolam and resulting in prolonged sedation. Increased steady-state concentration from 57 to 71 ng/mL.

P450-3A4 inhibitor may result in prolonged sedation due to decreased plasma clearance of midazolam.

May result in prolonged sedation due to decreased plasma clearance of midazolam.

CYP1A2, CYP2D6, and CYP3A inhibitor may increase mirtazapine plasma concentration. May require dose decrease.

Cimetidine increases nicardipine plasma levels. Patients receiving both drugs concomitantly should be carefully monitored.

Cimetidine increases nicardipine hydrochloride plasma levels. Patients receiving both drugs concomitantly should be carefully monitored.

Moderate CYP3A4 inhibitor that increases nimodipine plasma concentration. A study showed 50% increase in peak concentrations and 90% increase in area under curve. Blood pressure monitoring and dose reduction may be necessary.

Cimetidine 400 mg twice daily increased nisoldipine AUC and Cmax by 30-45%. Monitor for increased nisoldipine effects.

Increases paroxetine steady-state plasma concentrations by approximately 50%.

Cimetidine inhibits CYP450 enzymes, increasing paroxetine steady-state plasma concentrations by approximately 50%.

Cimetidine inhibits cytochrome P450 enzymes, potentially affecting paroxetine metabolism and pharmacokinetics.

Increases average steady state plasma concentration of pentoxifylline (~25%) and Metabolite I (~30%).

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

CYP3A inhibitor; concomitant use in patients with widespread and/or erythrodermic disease should be done with caution due to potential for increased pimecrolimus levels.

CYP450 inhibitor that may increase plasma concentrations of praziquantel.

Increases steady-state plasma concentrations of propafenone by 20%.

Increases steady-state plasma concentrations of propafenone by approximately 20%.

Cimetidine reduces hepatic metabolism of propranolol, delaying elimination and increasing blood levels. Dosage adjustment may be necessary.

CYP2D6, CYP1A2, and CYP2C19 inhibitor that may increase blood levels and/or toxicity of propranolol.

Cimetidine increases quinidine levels by unknown pharmacokinetic mechanisms.

Increases quinidine levels by pharmacokinetic mechanisms not well understood.

Nonspecific CYP450 inhibitor that may increase quinine levels. Ranitidine is preferred. Patients should be monitored closely for adverse events associated with quinine.

Nonspecific CYP450 inhibitor. Ranitidine is preferred over cimetidine when concomitant use is necessary. Patients should be monitored closely for adverse events.

Weak/moderate CYP3A4/P-gp inhibitor that may increase sirolimus concentrations. Monitor and adjust dosage as needed.

Cimetidine increases the bioavailability of risperidone by 64%, though it does not affect combined AUC of risperidone and 9-hydroxyrisperidone.

Cimetidine increases sertraline mean AUC by 50%, Cmax by 24%, and half-life by 26%. Clinical significance is unknown but monitoring is recommended.

Cimetidine increases sertraline AUC by 50%, Cmax by 24%, and half-life by 26%. Clinical significance unknown.

Sucralfate reduces the bioavailability of cimetidine. Dosing cimetidine 2 hours before sucralfate eliminates the interaction.

CYP3A4 inhibitor; concomitant administration in patients with widespread and/or erythrodermic disease should be done with caution.

CYP3A4 inhibitor; concomitant use in patients with widespread and/or erythrodermic disease should be done with caution due to potential increased tacrolimus absorption.

Decreases tamsulosin clearance by 26%, resulting in moderate increase in AUC by 44%. Use with caution.

Cimetidine decreases terbinafine clearance by 33%. Coadministration should be done with careful monitoring.

Cimetidine decreases terbinafine clearance by 33%, potentially increasing terbinafine exposure.

Cimetidine decreases terbinafine clearance by 33%, increasing terbinafine exposure.

Teriflunomide may increase exposure of cimetidine. Monitor patients and adjust dose as required.

H2 blocker cimetidine may cause additive bradycardic effect with thalidomide and should be used with caution.

Cimetidine inhibits theophylline clearance, resulting in increased serum theophylline concentrations. Smaller theophylline doses required when initiating therapy.

Cimetidine inhibits elimination of trimipramine, requiring downward dose adjustment when initiated and upward adjustment when discontinued.

Cimetidine inhibits elimination of trimipramine maleate. Downward dosage adjustment may be required if cimetidine is initiated; upward adjustment if discontinued.

Cimetidine inhibits first-pass metabolism of venlafaxine, reducing oral clearance by 43% and increasing AUC and Cmax by 60%. Caution advised for patients with hypertension, elderly patients, or those with hepatic dysfunction.

Inhibits first-pass metabolism of venlafaxine, increasing AUC and Cmax by about 60%. Caution advised in patients with pre-existing hypertension, elderly patients, and those with hepatic dysfunction.

Cimetidine reduces venlafaxine oral clearance by 43% and increases AUC and Cmax by 60%. Caution advised in patients with hypertension, elderly patients, or those with hepatic dysfunction.

Acute studies show clearance of verapamil either reduced or unchanged; chronic interaction not fully studied.

No significant pharmacokinetic changes observed with coadministration of cimetidine 300 mg QID with butorphanol 1 mg nasal spray.

Co-administration results in increased plasma concentrations of desloratadine but no clinically relevant changes in safety profile.

Cimetidine administration resulted in 10% increase in doxazosin AUC with slight but not significant increases in Cmax and half-life.

Weak CYP3A4 inhibitor. Effect not expected to exceed that of moderate inhibitors.

Co-administration of cimetidine with ibuprofen had no substantive effect on ibuprofen serum concentrations in human volunteer studies.

Pharmacokinetic interaction study showed no clinically significant effect on letrozole pharmacokinetics.

Pharmacokinetic interaction study showed no clinically significant effect on letrozole pharmacokinetics.

Pharmacokinetic interaction study with racemic cetirizine showed no interaction with cimetidine.

Coadministration increased losartan AUC by approximately 18% but did not affect active metabolite pharmacokinetics. No significant clinical interaction.

Weak CYP3A4 inhibitor; clinically significant increases in naloxegol concentrations are not expected and no dosage adjustments are necessary.

No significant effect on pravastatin AUC when given with cimetidine.

Multiple dose therapy with cimetidine has no effect on the pharmacokinetics of single doses of quinapril.

No statistically significant differences in rimantadine Cmax or AUC observed when co-administered with steady-state cimetidine.

Orally administered cimetidine dosed according to labeling does not alter the pharmacokinetic profile of temazepam.

Co-administration of cimetidine had no effect on tiagabine pharmacokinetics.

Coadministration led to 44% increase in trandolapril Cmax but no difference in trandolaprilat pharmacokinetics or ACE inhibition.

No clinically significant pharmacokinetic interactions were observed when coadministered with valsartan.

Cimetidine at 800 mg daily for 2 days did not affect ziprasidone pharmacokinetics.

Cimetidine at 800 mg once daily for 2 days did not affect ziprasidone pharmacokinetics.

Cimetidine 800 mg daily for 2 days did not affect ziprasidone pharmacokinetics.

No significant effect on zonisamide single dose pharmacokinetic parameters.

Reciprocal interactions may occur through cytochrome P450 system effects, though not studied.

Potential for drug-drug interaction due to possible competition for active tubular secretion via base-secreting system.

Cimetidine has demonstrated interference with elimination of some quinolones, resulting in significant increases in half-life and AUC. Potential for interaction with ofloxacin has not been studied.

Drug interaction studies conducted; specific interaction details not completed in provided text.