LAUSR

Since the beginning of the COVID-19 pandemic, efforts have been made to develop new therapies for COVID19.1,2 The drugs developed in the meantime focus on completing a COVID-19 response strategy to prevent serious illness, hospitalization, and death fromCOVID19, without constituting an alternative to vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).3 The first orally administered COVID19 drug was the repurposed dexamethasone; in a largescale trial, it was shown to be successful in reducing inflammation, which is known to lead to organ failure and death.4 It must be noted that this drug is not an antiviral and does not kill or inactivate the virus. Its mechanism is mainly to modulate the immune response to the virus. More recently, new drugs have been approved for oral use in patients with COVID-19. Merck Sharp & Dohme B.V. was the first company to produce an oral antiviral, molnupiravir, successfully and to license it in the UK market as Lagevrio. Molnupiravir is a prodrug that is metabolized to the ribonucleoside analogue Nhydroxycytidine (NHC). NHC distributes into cells, where it is phosphorylated to form the pharmacologically active ribonucleoside triphosphate. NHC triphosphate incorporation into viral RNA by the viral RNA polymerase results in an accumulation of errors in the viral genome, leading to the inhibition of replication.5 The MOVe-OUT study6 (Table 1), a phase 3 doubleblind randomized controlled trial, found evidence to recommend the use of this drug in the treatment of adults withmild tomoderateCOVID-19who arewithin 5 days of symptom onset. In this trial, molnupiravir was shown to reduce the chances of progressing to severe illness and death by about 30%. In addition, molnupiravir is also recommended for people for whom alternative antiviral therapies are not affordable or clinically appropriate. The proportion of adverse events (AEs) was similar in the molnupiravir group and the placebo group, at 30% and 33%, respectively. AEs that occurred in ≥2% of participants were COVID19 pneumonia and bacterial pneumonia. Moreover, in the interim analysis of the MOVe-OUT study, the most common AE occurring in ≥1% of participants during treatment and 14 days after the last dose were diarrhea, nausea, dizziness, and headache. Afterwards, Pfizer Europe MA EEIG announced their own oral antiviral, nirmatrelvir, which is marketed in combination with the already existing antiviral ritonavir (Paxlovid) and showed an impressive result of about 89% efficacy in preventing serious