Major
Fluconazole × tacrolimus
Antifungals, triazole derivatives×Calcineurin inhibitor (immunosuppressant)
Mechanism
Fluconazole at 200 mg/day or above blocks CYP3A4 – the main tacrolimus metabolic route. Tacrolimus plasma levels rise 2- to 3-fold, with nephrotoxicity and neurotoxicity risks.
Symptoms
Acute nephrotoxicity: rising creatinine and falling glomerular filtration rate. Tremor, headache, hypertension, hyperglycaemia, hyperkalaemia. In transplant patients: accelerated graft function decline.
Management
For short fluconazole courses (up to 7 days), reduce tacrolimus by 30% and check trough (C0) daily. For prolonged systemic therapy, alternative antifungals (echinocandins) or titrate tacrolimus to level.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.