Oseltamivir for coronavirus illness: post-hoc exploratory analysis of an open-label, pragmatic, randomised controlled trial in European primary care from 2016 to 2018.

Background: Patients infected with the novel coronavirus (SARS-CoV-2) are being treated empirically with oseltamivir, but there is little evidence from randomised controlled trials to support the treatment of coronavirus infections with oseltamivir.

Aim: To determine whether adding oseltamivir to usual care reduces time to recovery in symptomatic patients who have tested positive for coronavirus (not including SARS-CoV-2).

Design And Setting: Exploratory analysis of data from an open-label, pragmatic, randomised controlled trial during three influenza seasons, from 2016 to 2018, in primary care research networks, in 15 European countries.

Method: Patients aged ≥1 year presenting to primary care with influenza-like illness (ILI), and who tested positive for coronavirus (not including SARS-CoV-2), were randomised to usual care or usual care plus oseltamivir. The primary outcome was time to recovery defined as a return to usual activities, with minor or absent fever, headache, and muscle ache.

Results: Coronaviruses (CoV-229E, CoV-OC43, CoV-KU1 and CoV-NL63) were identified in 308 (9%) out of 3266 randomised participants in the trial; 153 of these were allocated to usual care and 155 to usual care plus oseltamivir; the primary outcome was ascertained in 136 and 147 participants, respectively. The median time to recovery was shorter in patients randomised to oseltamivir: 4 days (interquartile range [IQR] 3-6) versus 5 days (IQR 3-8; hazard ratio 1.31; 95% confidence interval = 1.03 to 1.66; = 0.026).

Conclusion: Primary care patients with ILI testing positive for coronavirus (not including SARS-CoV-2) recovered sooner when oseltamivir was added to usual care compared with usual care alone. This may be of relevance to the primary care management of COVID-19.