Pfizer’s oral antiviral Paxlovid (nirmatrelvir/ritonavir) is strongly recommended for patients with non-severe COVID with greater hospitalisation risk, such as unvaccinated, older, or immunosuppressed patients, according to a WHO Guideline Development Group writing in The BMJ.
The experts explained that Pfizer’s Paxlovid, a comnbination of nirmatrelvir and ritonavir tablets, is likely a better choice for these patients because it may prevent more hospitalisations than the alternatives, is safer than molnupiravir, and is easier to administer than intravenous options such as remdesivir and antibody treatments.
Use in low-risk patients is not recommended due to trivial benefits. It is also not recommended for patients with severe or critical COVID, as there are currently no trial data on nirmatrelvir/ritonavir for this group.
Their recommendation is based on new data from two randomised controlled trials with 3100 patients.
In these trials, moderate certainty evidence showed that nirmatrelvir/ritonavir reduced hospital admission (84 fewer admissions per 1000 patients), low certainty evidence suggested no important difference in mortality, and high certainty evidence suggested little or no risk of adverse effects leading to drug discontinuation.
Additionally, WHO also makes a conditional (weak) recommendation to use the antiviral drug remdesivir for patients with non-severe COVID at highest risk of hospitalisation.
This is based on new data from five randomised controlled trials involving 2700 patients and replaces a previous recommendation against treatment with remdesivir in all patients with covid-19 regardless of disease severity.
Antiviral drugs should be administered as early as possible, but this may be challenging in low- and middle-income countries, the panel noted, and also that access to these drugs is tied to COVID tests.
The emergence of resistance is also an uncertain risk, they add.
This guidance adds to previous conditional recommendations for the use of molnupiravir for high-risk patients with non-severe COVID and for the use of sotrovimab or casirivimab-imdevimab (monoclonal antibody treatments) in selected patients; and against the use of convalescent plasma, ivermectin and hydroxychloroquine in patients with COVID regardless of disease severity. For patients with severe COVID, WHO strongly recommends corticosteroids, with the addition of IL-6 receptor blockers or baricitinib.