Abstract and Introduction
Abstract
Objective: To determine the effect of oseltamivir (75mg twice daily) on time to return to baseline health, sleep and activity in patients with laboratory-confirmed influenza infection.
Patients and Methods: Data from 1642 otherwise healthy adults (aged 13−64years), who had experienced a febrile influenza-like illness (>38°C) of up to 36hours' duration together with at least one respiratory and one systemic/constitutional symptom, were pooled from fourrandomised, double-blind, placebo-controlled clinical trials. Patients in these trials had been randomised to receive either oseltamivir or placebo for 5 days and had been allowed unlimited use of symptom-relief medications. The primary analysis examined the effect of oseltamivir treatment on patients' general health status, sleep and normal activities as measured by visual analogue scales. Secondary analyses examined the possible effects of gender, influenza type, smoking, employment status and time to treatment (≤ or >24 hours) on these endpoints.
Results: Oseltamivir significantly reduced the time taken to return to baseline health, sleep and activity across all pooled patients (p < 0.0001) and increased the proportion of patients returning to full activity within the first 7 days following treatment start. Gender, smoking status, time to treatment, influenza subtype and employment status had no appreciable effect on the effectiveness of oseltamivir.
Conclusions: In otherwise healthy adults, oseltamivir reduces the time to return to pre-illness levels of health, sleep and activity, and may help to decrease the overall burden of influenza on society. This provides an important rationale for the early use of antiviral treatment, such as oseltamivir, for the treatment of influenza in otherwise healthy adults and adolescents.
Introduction
Influenza epidemics cause substantial morbidity and often excess mortality in all age groups, especially the elderly. On average, up to 10% of the population develop influenza annually, with the majority affected being otherwise healthy adults. Influenza infections are associated with an average of 2−3 days in bed, 5−6 days of restricted activity and 3 days lost from work. Consequently, annual influenza outbreaks are associated with significant healthcare costs and indirect costs due to absenteeism and lost work productivity.
Immunisation is the primary means of influenza prevention, although it is not routinely recommended or utilised in otherwise healthy adults and children ≥2 years. If administered early in the course of illness, antiviral agents can provide important therapeutic benefits in both adults and children afflicted with acute influenza. Among available anti-viral drugs, oseltamivir is a potent, specific neuraminidase inhibitor that can be administered orally and is effective in the management of both influenza A and influenza B infections. Oseltamivir has been shown to significantly reduce the duration of symptoms and severity of illness, as well as the risk of physician-diagnosed complications, in otherwise healthy adult patients infected with influenza. However, influenza can negatively impact patients' quality of life (QOL) far beyond the time for symptom alleviation and delay the time to return to usual health and activities. Individual study results have indicated beneficial effects on these outcomes with early oseltamivir treatment, but, as yet, no large-scale analysis of QOL data has been performed.
The current study evaluated the effects of oseltamivir treatment on self-rated health status, sleep, and normal daily activities in influenza-infected patients. Effects were examined in a large cohort of otherwise healthy adult and adolescent patients from four pooled clinical trials of oseltamivir treatment of naturally acquired influenza illness.