Comparison of the effects of peramivir and oseltamivir on the rise in platelet count in patients with or without proven influenza

Objective: Neuraminidase (sialidase) inhibitors are considered to delay platelet clearance through the inhibition of platelet desialylation. A novel neuraminidase inhibitor, peramivir, was recently approved for intravenous administration by the US FDA. We aimed to compare the effects of peramivir and oseltamivir on patient platelet count. Materials and methods: Consecutive patients who were treated with peramivir or tested positive for influenza between January 2015 and December 2017 were analyzed. The analysis included 461 patients with platelet counts available; the patients were divided into three groups: patients with proven influenza treated with peramivir (n = 305); those treated with peramivir without proven influenza (n = 83), and those with proven influenza treated with oseltamivir (n = 73). Results: Patients treated with peramivir did not show an increase in platelet count from the baseline count, regardless of proven influenza (from 263.4 × 10 ⁹ /L to 267.4 × 10 ⁹ /L; 9 = 0.410) or not (from 257.1 × 10 ⁹ /L to 255.4 × 10 ⁹ /L; p = 0.873); wheeras for patients treated with oseltamivir, a significant increase above the baseline was found (from 223.3 × 10 ⁹ /L to 249.9 × 10 ⁹ /L; p = 0.016), although it was transient. Conclusion: Peramivir and oseltamivir appear to have different effects on patient platelet count when administered at the recommended doses.