P eramivir, an intravenous investiga- tional neuraminidase inhibitor with potent in vitro activity against a variety of influenza A and B viruses, including H1N1 and H3N2 strains, is under devel- opment for influenza requiring hospital- ization and is currently approved for use in Japan and South Korea. 1 In Phase 2 studies, it was shown to have similar safety and efficacy to oral oseltamivir in individuals hospitalized with influenza. 2 Based on available data presented to the Food and Drug Administration (FDA), peramivir was temporarily provided an Emergency Use Authorization (EUA) from October 23, 2009, to June 23, 2010, by the FDA as a result of the 2009 H1N1 pandemic. 3 Phase 3 studies are ongoing to further investigate its safety and efficacy in hospitalized patients. Because peramivir may be an impor- tant treatment option for hospitalized patients with influenza, clinicians sought correct dosing schemes for patients under- going continual renal replacement therapy (CRRT). 4 The concern emanated from the fact that kidney failure and renal replacement therapy are common among patients infected with H1N1 influenza; the latter occurrence has been estimat- ed at 5-18%. 5,6 Thus, 90% clearance of peramivir by the kid- ney is clinically relevant to the renally impaired patient. 7 Peramivir, when used in patients with normal renal function, exhibits half-lives between 8 and 21 hours, 7 and a 600-mg single daily dose (ie, the recommended dose in patients with normal renal function) 8 achieves predicted maximum steady- state serum concentrations of 34,100 ng/mL within 7 days of dosing. 7 Severe renal dysfunction leads to accumulation and has been associated with an increased mean area under the curve (AUC) of 530%. 9 Because peramivir has low plasma protein binding and is distributed in the intravascular space, it is available for clearance by extracorporeal devices, and data are needed to guide dosing in renal replacement therapy. 7 Case Report A 73-kg, 18-year-old male presented to the emergency department of an outside hospital with chills, myalgias, and dyspnea. A nasal swab was positive for influenza A. The patient was intubated, initiated on broad-spectrum an- tibacterials, and transferred to our hospital. Upon the pa- tient’s arrival, an influenza test using short-panel Prodesse real-time polymerase chain reaction (PCR) assay (Gen- Probe, San Diego, CA) was positive for H1N1 influenza A. Oral oseltamivir was started; however, over the course Pharmacokinetic Assessment of Peramivir in a Hospitalized Adult Undergoing Continuous Venovenous Hemofiltration Marc H Scheetz, Milena M Griffith, Cybele Ghossein, Alan S Hollister, and Michael G Ison Author information provided at end of text. The Annals of Pharmacotherapy ■ 2011 December, Volume 45 ■ e64 theannals.com CASE REPORTS OBJECTIVE: To report a sieving coefficient for peramivir in a patient receiving continuous venovenous hemofiltration (CVVH). CASE SUMMARY: An 18-year-old male presented with chills, myalgias, and dyspnea and was hospitalized. Nasal secretions were positive for influenza by rapid antigen test at an outside facility and oseltamivir was commenced. Oral absorption was predicted to be unreliable, and intravenous peramivir was accessed as an emergency investigational new drug applicaiton (eIND). CVVH was initiated after the development of acute renal failure, with blood samples collected to determine peramivir concentrations. DISCUSSION: Peramivir, an intravenous investigational neuraminidase inhibitor with activity against influenza viruses, has limited data for dosing in the setting of CVVH. A single patient received 600 mg of peramivir intravenously and had blood and ultrafiltrate concentrations measured serially. A sieving coefficient of approximately 0.9 was identified. CONCLUSIONS: Peramivir is well cleared by CVVH, and drug exposure is potentially predictable based on flow rates. Further study is necessary. KEY WORDS: CVVH, influenza A, peramivir, pharmacokinetics. Ann Pharmacother 2011;45:e64. Published Online, 22 Nov 2011, theannals.com, DOI 10.1345/aph.1Q437