Rifabutin and Voriconazole interaction
Rifabutin and Voriconazole: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Voriconazole label · effective 2026-06-02
…reactions [see Drug Interactions (7) ]: • Eplerenone • Ergot alkaloids (e.g., ergotamine, dihydroergotamine) • Finerenone • Ivabradine • Lurasidone • Naloxegol • Pimozide • Quinidine • Rifabutin [see Clinical Pharmacology (12.3) ] • Sirolimus [see Clinical Pharmacology (12.3) ] • Tolvaptan • Venetoclax: Coadministration at initiation and during the ramp-up phase is…
• Long-acting barbiturates • Rifabutin • Rifampin • Ritonavir Concomitant use with high-dose ritonavir (400 mg every 12 hours) is contraindicated.
…Management Recommendations Rifampin Results based on in vivo clinical studies generally following repeat oral dosing with 200 mg every 12 hours voriconazole to healthy subjects and Rifabutin (CYP450 Induction) Significantly Reduced Contraindicated Efavirenz (400 mg every 24 hours) Results based on in vivo clinical study following repeat oral dosing with 400 mg…
…based on in vivo clinical studies generally following repeat oral dosing with 200 mg BID voriconazole to healthy subjects (CYP3A4 Inhibition) Significantly Increased Contraindicated Rifabutin (CYP3A4 Inhibition) Significantly Increased Contraindicated Efavirenz (400 mg every 24 hours) Results based on in vivo clinical study following repeat oral dosing with 400…
From the Rifabutin label · effective 2026-09-01
Voriconazole 400 mg twice a day for 7 days (maintenance dose) 300 mg once a day for 7 days Healthy male subjects (12) ↑ AUC by 331%, ↑ C max by 195% ↑ AUC by ~100%, ↑ C max by ~100% compared to voriconazole 200 mg twice a day alone CONTRAINDICATED ANTI-PCP (Pneumocystis carinii pneumonia) Dapsone 50 mg once a day 300 mg once a day HIV-infected patients (16)
Effect of Other Drugs on Rifabutin Pharmacokinetics Some drugs that inhibit CYP3A may significantly increase the plasma concentration of rifabutin.
Therefore, carefully monitor for rifabutin associated adverse events in those patients also receiving CYP3A inhibitors, which include fluconazole and clarithromycin.
In some cases, the dosage of rifabutin may need to be reduced when it is co-administered with CYP3A inhibitors.
ANTIFUNGALS Fluconazole 200 mg once a day for 2 weeks 300 mg once a day for 2 weeks HIV-infected patients (12) ↑ AUC by 82%, ↑ C max by 88% ↔ Monitor for rifabutin associated adverse events.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.