Objective: Peramivir is a neuraminidase inhibitor having activity against various influenza A and B subtypes. The main route of elimination is the kidney and a dose reduction is justified for multiple-day therapy when the creatinine clearance is < 50 mL/min. Before the 2009 influenza pandemic, dosing guidelines did not exist for patients receiving continuous renal replacement therapy (CRRT). This case report provides data on the dialysis membrane saturation coefficient (SA) and pharmacokinetic parameters of peramivir in a 29-year-old female receiving continuous veno-venous hemodiafiltration (CVVHDF), a mode of CRRT.
Methods: Plasma and effluent samples were collected to calculate the saturation coefficient, plasma half-life, maximum and minimum plasma concentrations, and area under the plasma drug concentration-time curve (AUC) for peramivir. CVVHDF was performed using a Prisma pump and an AN69 filter. During peramivir sampling, the dialysate flow rate was 16.7 mL/min. The mean total ultrafiltrate produced was 14.2 mL/min. To calculate a saturation coefficient (SA), simultaneous sampling of blood and effluent was performed. Pre- and post-filter as well as effluent samples were obtained 4.5 and 8.5 hours following the 3rd dose of 480 mg. Plasma concentrations were also obtained at several time points and the AUC estimated from 0 to 24 hours (AUC0-24).
Results: The maximum plasma concentration (C30min) was 19,477 ng/mL, the minimum plasma concentration (Cmin) 2,750 ng/mL, and AUC0-24 196,166 ng x h/mL. The estimated plasma half-life was 8.2 hours with a log-linear decrease over the 24-hour period suggesting significant extracorporeal clearance. The calculated SA was 0.98, similar to an estimated SA of 1.
Conclusion: Peramivir is readily cleared by CVVHDF having a calculated SA close to 1. The maximum and minimum plasma concentrations, AUC0-24, and plasma half-life was similar to those previously reported. These data will be useful in determining appropriate peramivir dosing regimens for severely ill influenza patients with acute renal impairment managed by CVVHDF.