Nirmatrelvir/ritonavir and molnuipiravir in the treatment of mild/moderate COVID-19: results of a real-life study

ABSTRACT

Molnupiravir and Nirmatrelvir are the first available oral antivirals (OA) active against SARS-CoV-2. However, the trials evaluating the efficacy of OAs involved patients unvaccinated and infected with variants different from those currently circulating. The purpose of this study is to provide real-life data on the efficacy and safety of OAs during the omicron surge of COVID-19 pandemic in a cohort of mostly vaccinated patients. We conducted a retrospective study on patients with confirmed SARS-CoV-2 infection treated with OAs during the omicron surge in Italy. We enrolled 257 patients. Of these, 146 (56.8%) were treated with molnupiravir and 111 (43.2%) with nirmatrelvir/ritonavir. Patients in molnupiravir group were older, had a lower body mass index, and a higher rate of chronic heart disease than those treated with nirmatrelvir/ritonavir. During the 14-day follow-up, four hospitalizations were recorded (1.6%), three in molnupiravir (2.1%) and 1 in nirmatrelvir/ritonavir (0.9%) group. Only one patient (who had received molnupiravir) died. Median time-to-negativity of nasal swab was 8 days (8 days in nirmatrelvir/ritonavir vs. 10 days in molnupiravir group, p<0.01). Globally, we recorded 37 adverse drug reactions (mainly dysgeusia, diarrhea, and nausea) in 31 of 257 individuals (12.1%). Only two patients (0.8%), both receiving molnupiravir, terminated treatment due to the development of adverse drug reactions. In conclusion, during the omicron surge, in a population of mostly vaccinated patients treated with molnupiravir or nirmatrelvir/ritonavir, we observed a low rate of hospitalization, death, and adverse drug reactions. These rates were even lower than those reported in pivotal trials.