Study objective: To determine rates of drug-induced, rare, serious adverse events affecting the liver, kidneys, skin, or blood, occurring within 45 days of completing a prescription or refill for itraconazole or fluconazole.
Design: Population-based follow-up study
Setting: United Kingdom-based General Practice Research Database.
Patients: Total of 54,803 users of either fluconazole or itraconazole.
Main results: Four patients were identified with illnesses for which a drug-induced etiology could not be ruled out; one with an elevated liver function test while taking itraconazole, one with thrombocytopenia, one with neutropenia, and one with an abnormal liver function test just after receiving fluconazole. For itraconazole the rate was 3.2/100,000 prescriptions (95% confidence interval [CI] 0.6-17.9) for serious, adverse liver events; for fluconazole 2.8/100,000 prescriptions (95% CI 0.8-10.3) for serious, adverse blood events and 1.4/100,000 prescriptions (95% CI 0.25-8.2) for serious, adverse liver events.
Conclusion: Itraconazole and fluconazole do not commonly cause rare, serious adverse events affecting the liver, kidneys, skin, or blood.