Interaction Drug Interaction Rifabutin, phenytoin, efavirenz, cimetidine Avoid coadministration unless the benefit outweighs the risks ( 7.6 , 7.7 , 7.8 , 7.9 ) Other drugs metabolized by CYP3A4 Consider dosage adjustment and monitor for adverse effects and toxicity ( 7.1 , 7.10 , 7.11 ) Digoxin Monitor digoxin plasma concentrations ( 7.12 ) Fosamprenavir Monitor for breakthrough fungal infections ( 7.6 , 7.13 ) 7.1 Immunosuppressants Metabolized by CYP3A4 Sirolimus: Concomitant administration of posaconazole with sirolimus increases the sirolimus blood concentrations by approximately 9-fold and can result in sirolimus toxicity. Fosamprenavir: Combining fosamprenavir with posaconazole may lead to decreased posaconazole plasma concentrations.
Source: FDA drug label - posaconazole delayed-release
Concomitant use of posaconazole and other benzodiazepines metabolized by CYP3A4 (e.g., alprazolam, triazolam) could result in increased plasma concentrations of these benzodiazepines.
Source: FDA drug label - posaconazole delayed-release
Ritonavir and Atazanavir: Ritonavir and atazanavir are metabolized by CYP3A4 and posaconazole increases plasma concentrations of these drugs [see Clinical Pharmacology ( 12.3 )] . Frequent monitoring of adverse effects and toxicity of ritonavir and atazanavir should be performed during coadministration with posaconazole.
Source: FDA drug label - posaconazole delayed-release
7.11 Calcium Channel Blockers Metabolized by CYP3A4 Posaconazole may increase the plasma concentrations of calcium channel blockers metabolized by CYP3A4 (e.g., verapamil, diltiazem, nifedipine, nicardipine, felodipine).
Source: FDA drug label - posaconazole delayed-release
7.13 Gastrointestinal Motility Agents Concomitant administration of metoclopramide with posaconazole delayed-release tablets did not affect the pharmacokinetics of posaconazole [see Clinical Pharmacology ( 12.3 )] . No dosage adjustment of posaconazole delayed-release tablets is required when given concomitantly with metoclopramide.
Source: FDA drug label - posaconazole delayed-release
7.5 Benzodiazepines Metabolized by CYP3A4 Concomitant administration of posaconazole with midazolam increases the midazolam plasma concentrations by approximately 5-fold. Increased plasma midazolam concentrations could potentiate and prolong hypnotic and sedative effects.
Source: FDA drug label - posaconazole delayed-release
7.11 Calcium Channel Blockers Metabolized by CYP3A4 Posaconazole may increase the plasma concentrations of calcium channel blockers metabolized by CYP3A4 (e.g., verapamil, diltiazem, nifedipine, nicardipine, felodipine).
Source: FDA drug label - posaconazole delayed-release
7.11 Calcium Channel Blockers Metabolized by CYP3A4 Posaconazole may increase the plasma concentrations of calcium channel blockers metabolized by CYP3A4 (e.g., verapamil, diltiazem, nifedipine, nicardipine, felodipine).
Source: FDA drug label - posaconazole delayed-release
7 DRUG INTERACTIONS Posaconazole is primarily metabolized via UDP glucuronosyltransferase and is a substrate of p glycoprotein (P-gp) efflux. Therefore, inhibitors or inducers of these clearance pathways may affect posaconazole plasma concentrations. Coadministration of drugs that can decrease the plasma concentrations of posaconazole should generally be avoided unless the benefit outweighs the risk.
Source: FDA drug label - posaconazole delayed-release
Ritonavir and Atazanavir: Ritonavir and atazanavir are metabolized by CYP3A4 and posaconazole increases plasma concentrations of these drugs [see Clinical Pharmacology ( 12.3 )] . Frequent monitoring of adverse effects and toxicity of ritonavir and atazanavir should be performed during coadministration with posaconazole.
Source: FDA drug label - posaconazole delayed-release
7.3 HMG-CoA Reductase Inhibitors (Statins) Primarily Metabolized Through CYP3A4 Concomitant administration of posaconazole with simvastatin increases the simvastatin plasma concentrations by approximately 10-fold.
Source: FDA drug label - posaconazole delayed-release
Concomitant use of posaconazole and other benzodiazepines metabolized by CYP3A4 (e.g., alprazolam, triazolam) could result in increased plasma concentrations of these benzodiazepines.
Source: FDA drug label - posaconazole delayed-release