ABSTRACT
BACKGROUND: Rifapentine is a rifamycin with unique bactericidal activity against Mycobacterium tuberculosis. It is also a potent inducer of CYP3A activity. However, the duration of rifapentine-induced hepatic enzyme activity after withdrawal is unclear. CASE REPORT: We report a case of a patient with Aspergillus meningitis treated with voriconazole after discontinuing rifapentine. Within ten days of rifapentine discontinuation, serum levels of voriconazole failed to reach the effective treatment range. CONCLUSIONS: Rifapentine is a potent inducer of hepatic microsomal enzymes. The induction of hepatic enzymes may exceed ten days after rifapentine discontinuation. Clinicians should be reminded of residual enzyme induction by rifapentine, especially when treating critically ill patients.