PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

rifampin vs voriconazole

Side-by-side comparison of rifampin and voriconazole. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

major Known Drug Interaction

Table 10: Effect of Other Drugs on Voriconazole Pharmacokinetics [see Clinical Pharmacology (12.3)] Drug/Drug Class (Mechanism of Interaction by the Drug) Voriconazole Plasma Exposure (C max and AUC τ after 200 mg every 12 hours) Recommendations for Voriconazole Dosage Adjustment/Comments 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...

Recommendation: You should not take these two drugs at the same time. Your doctor will need to find an alternative medication that does not interfere with your treatment.

Drug Class
rifampin Rifamycin Antibiotic
voriconazole Azole Antifungal
Type
rifampin Prescription
voriconazole Prescription
Summary
rifampin

Rifampin is an antibiotic medicine. It fights bacteria in your body to treat infections.

voriconazole

Voriconazole (Vfend) is an antifungal medicine. It is used to treat serious fungal infections in adults and children 2 years and older.

What It Treats
rifampin

Rifampin treats tuberculosis (TB) and helps eliminate the bacteria that cause meningitis from your nose and throat. It is important to use rifampin only for infections that are proven or strongly suspected to be caused by bacteria. This helps to prevent bacteria from becoming resistant to the medicine.

voriconazole

This medicine treats several types of fungal infections. It is used for invasive aspergillosis, a lung infection. It also treats candidemia (a blood infection) and other Candida infections in the skin, abdomen, kidney, bladder, and wounds. Voriconazole can also treat esophageal candidiasis (a throat infection) and serious infections caused by Scedosporium and Fusarium fungi.

How It Works
rifampin

Rifampin works by stopping bacteria from growing and multiplying. It does this by blocking a key enzyme that the bacteria need to make proteins. This helps your body fight off the infection.

voriconazole

Voriconazole belongs to a class of drugs called azole antifungals. It works by stopping the growth of fungi. It does this by interfering with the production of the fungal cell membrane.

Common Side Effects
rifampin
  • Heartburn
  • Upset stomach
  • Loss of appetite
  • Nausea
  • Vomiting
voriconazole
  • Visual disturbances
  • Fever
  • Nausea
  • Rash
  • Vomiting
FAERS Reports
rifampin
  • Drug Interaction 970
  • Drug Reaction With Eosinophilia And Systemic Symptoms 727
  • Nausea 628
  • Condition Aggravated 550
  • Pyrexia 541
voriconazole
  • The medicine is interacting with another medicine 2,315
  • Death 1,460
  • Fever 1,411
  • Lung infection 1,322
  • The condition is getting worse 1,093
Serious Warnings
rifampin

Rifampin can cause liver problems. Tell your doctor right away if you have yellowing of the skin or eyes, dark urine, or stomach pain. Rifampin can also cause blood problems. Tell your doctor if you have unusual bleeding or bruising.

voriconazole

Voriconazole can cause serious liver problems. Your doctor will check your liver function with blood tests before and during treatment. This medicine can also cause heart rhythm problems. Make sure your potassium, magnesium, and calcium levels are normal before starting. Voriconazole can also cause severe skin reactions and make you sensitive to sunlight. Avoid sunlight and wear protective clothing. This medicine can harm an unborn baby, so women who can get pregnant should use effective birth control.

Pregnancy
rifampin

Tell your doctor if you are pregnant or plan to become pregnant. Rifampin can make birth control pills less effective, so use other forms of birth control. Talk to your doctor if you are breastfeeding.

voriconazole

Voriconazole can cause harm to an unborn baby. If you are pregnant or could become pregnant, talk to your doctor. It is not known if voriconazole passes into breast milk. Talk to your doctor about the risks and benefits of breastfeeding while taking this medicine.

Also Compare, Nearby Drugs

How to Read This rifampin vs voriconazole Comparison

rifampin is classified in the Rifamycin Antibiotic drug class, while voriconazole sits within the Azole Antifungal class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, rifampin has 3,416 submissions while voriconazole has 7,601. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known major interaction flagged in FDA labeling, attributed to rifampin causes your body to break down voriconazole much faster than normal. this makes the voriconazole level in your blood too low to effectively treat your infection.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between rifampin and voriconazole - always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.