Pharmacokinetics of Caspofungin Increased Dosage in a Patient on Rifampin-Containing Anti-Tubercular Treatment.

We describe a patient treated with caspofungin and rifampin; after increasing the dosage of the former (70 mg/day) we observed an unexpectedly lower plasma exposure (AUC(0 24) 79.5 mu g/ml*h vs. 108.8 mu g/ml*h). Although rifampin-mediated complete enzyme induction may take longer than 2 weeks, the clinical advantage of an increased caspofungin dose deserves clinical investigation.