Critically ill patients requiring renal replacement therapy commonly experience pharmacokinetic alterations. This case report describes the pharmacokinetics of peramivir (Rapivab, BioCryst Pharmaceuticals, Inc, Durham, NC), the first US Food and Drug Administration-approved intravenous neuraminidase inhibitor for the treatment of influenza, in an adolescent patient receiving continuous renal replacement therapy (CRRT). A 49.5-kg, 17-year-old Caucasian female presented with fever, cough, and persistent hypoxia. She quickly progressed to acute respiratory and renal failure in the setting of viral septic shock as a result of a severe influenza H1N1 infection. On hospital day 3, therapy was switched from oseltamivir (Tamiflu, Roche Laboratories Inc, Nutley, NJ) to peramivir owing to the concern for inadequate enteral absorption. On the third day of peramivir treatment, at a dose of 200 mg daily, peramivir serum concentrations revealed a smaller peak concentration, larger volumes of distribution, similar 24-hour area under the curve, and a shorter half-life as compared to adult patients with normal renal function. This illustrated the significant differences in pharmacokinetics when administered in the setting of CRRT. The patient had resolution of viral infection as evidenced by negative respiratory viral panel polymerase chain reaction at hospital day 14 and was eventually discharged at her baseline.
Keywords: CRRT; adolescent; case report; continuous renal replacement therapy; influenza; pediatric peramivir; pharmacokinetics; therapeutic drug monitoring.