Oral oseltamivir reduces febrile illness in patients considered at high risk of influenza complications

Abstract

Background: Influenza poses a serious burden to patients at high risk of influenza complications and vaccination against the disease may be inadequate due to poor uptake rates or impaired immune response. We investigated the efficacy and safety of oral oseltamivir treatment in two studies of elderly patients or those with underlying cardiac/pulmonary disease (at-risk). Methods: 1138 high-risk patients (13–97 years) presenting within 36 h of onset of influenza symptoms were randomized to oseltamivir 75 mg or placebo bid for 5 days. Endpoints included duration of febrile illness, fever and other symptoms, viral shedding and complications. Results: 727 (64%) patients were influenza-infected (ITTI) (at-risk: placebo 133, oseltamivir 118; elderly: placebo 254, oseltamivir 222). In the ITTI population, oseltamivir reduced median duration of fever by 37% in at-risk patients and by 25% in elderly patients compared with placebo. Acute febrile illness and respiratory complications were reduced with oseltamivir treatment by approximately 30% in both patient populations. Viral shedding was reduced by 70% in oseltamivir-treated at-risk patients. Oseltamivir was well tolerated, with similar incidence of gastrointestinal events reported in placebo and oseltamivir recipients. Conclusions: Oseltamivir reduces the duration of fever, febrile illness, individual influenza symptoms and complications in high-risk patients.