Does Indinavir Interact with Voriconazole?

Indinavir and Voriconazole have a contraindicated drug interaction according to U.S. FDA drug labeling data. Other HIV Protease Inhibitors (CYP3A4 Inhibition) In Vivo Studies Showed No Significant Effects of Indinavir on Voriconazole Exposure No dosage adjustment in the voriconazole dosage needed when coadministered with indinavir In Vitro Studies Demonstrated Potential for Inhibition of Voriconazole Metabolism (Increased Plasma Exposure) Frequent monitoring for adverse events and toxicity related to voriconazole when coadministered with other HIV protease inhibitors Other NNRTIs*** (CYP3A4 Inhibition or CYP450 Induction) In Vitro Studies Demonstrated Potential for Inhibition of Voriconazole Metabolism by Delavirdine and Other NNRTIs (Increased Plasma Exposure) Frequent monitoring for adverse events and toxicity related to voriconazole A Voriconazole-Efavirenz Drug Interaction Study Demonstrated the Potential for the Metabolism of Voriconazole to be Induced by Efavirenz and Other NNRTIs (Decreased Plasma Exposure) Careful assessment of voriconazole effectiveness Table 11:Effect of Voriconazole on Pharmacokinetics of Other Drugs [ see Clinical Pharmacology ( 12.3 )] Drug/Drug Class (Mechanism of Interaction by Voriconazole) Drug Plasma Exposure (C max and AUC τ ) Recommendations for Drug Dosage Adjustment/Comments * Results based on in vivo clinical studies generally following repeat oral dosing with 200 mg BID voriconazole to healthy subjects ** Results based on in vivo clinical study following repeat oral dosing with 400 mg every 12 hours for 1 day, then 200 mg every 12 hours for at least 2 days voriconazole to healthy subjects *** Results based on in vivo clinical study following repeat oral dosing with 400 mg every 12 hours for 1 day, then 200 mg every 12 hours for 4 days voriconazole to subjects receiving a methadone maintenance dose (30-100 mg every 24 hours) **** Non-Steroidal Anti-Inflammatory Drug ***** Non-Nucleoside Reverse Transcriptase Inhibitors Sirolimus* (CYP3A4 Inhibition) Significantly Increased Contraindicated Rifabutin* (CYP3A4 Inhibition) Significantly Increased Contraindicated Efavirenz (400 mg every 24 hours)** (CYP3A4 Inhibition) Significantly Increased Contraindicated Efavirenz (300 mg every 24 hours)** (CYP3A4 Inhibition) Slight Increase in AUC τ When voriconazole is coadministered with efavirenz, voriconazole oral maintenance dose should be increased to 400 mg every 12 hours and efavirenz should be decreased to 300 mg every 24 hours High-dose Ritonavir (400 mg every 12 hours)** (CYP3A4 Inhibition) No Significant Effect of Voriconazole on Ritonavir C max or AUC τ Contraindicated because of significant reduction of voriconazole C max and AUCτ Low-dose Ritonavir (100 mg every 12 hours)** Slight Decrease in Ritonavir C max and AUCτ Coadministration of voriconazole and low-dose ritonavir (100 mg every 12 hours) should be avoided (due to the reduction in voriconazole C max and AUCτ) unless an assessment of the benefit/risk to the patient justifies the use of voriconazole Cisapride, Pimozide, Quinidine (CYP3A4 Inhibition) Not Studied In Vivo or In Vitro, but Drug Plasma Exposure Likely to be Increased Contraindicated because of potential for QT prolongation and rare occurrence of torsade de pointes Ergot Alkaloids (CYP450 Inhibition) Not Studied In Vivo or In Vitro, but Drug Plasma Exposure Likely to be Increased Contraindicated Naloxegol (CYP3A4 Inhibition) Not Studied In Vivo or In Vitro , but Drug Plasma Exposure Likely to be Increased which may Increase the Risk of Adverse Reactions Contraindicated Tolvaptan (CYP3A4 Inhibition) Although Not Studied Clinically, Voriconazole is Likely to Significantly Increase the Plasma Concentrations of Tolvaptan Contraindicated Cyclosporine* (CYP3A4 Inhibition) AUC τ Significantly Increased; No Significant Effect on C max When initiating therapy with voriconazole tablets in patients already receiving cyclosporine, reduce the cyclosporine dose to one-half of the starting dose and follow with frequent monitoring of cyclosporine blood levels. Other HIV Protease Inhibitors (CYP3A4 Inhibition) In Vivo Studies Showed No Significant Effects on Indinavir Exposure In Vitro Studies Demonstrated Potential for Voriconazole to Inhibit Metabolism (Increased Plasma Exposure) No dosage adjustment for indinavir when coadministered with voriconazole tablets Frequent monitoring for adverse events and toxicity related to other HIV protease inhibitors Other NNRTIs***** (CYP3A4 Inhibition) A Voriconazole-Efavirenz Drug Interaction Study Demonstrated the Potential for Voriconazole to Inhibit Metabolism of Other NNRTIs (Increased Plasma Exposure) Frequent monitoring for adverse events and toxicity related to NNRTI Benzodiazepines (CYP3A4 Inhibition) In Vitro Studies Demonstrated Potential for Voriconazole to Inhibit Metabolism (Increased Plasma Exposure) Frequent monitoring for adverse events and toxicity (i.e., prolonged sedation) related to benzodiazepines metabolized by CYP3A4 (e.g., midazolam, triazolam, alprazolam). Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.

Severity

Contraindicated

Voriconazole Class

Azole Antifungal

Management

Do not take together

Data Source

U.S. FDA via OpenFDA