Nirmatrelvir-ritonavir effective for outpatient treatment of COVID-19

For outpatient treatment of COVID-19, nirmatrelvir-ritonavir is effective for reducing 30-day hospitalization or death, while molnupiravir is associated with a reduction in 30-day mortality, according to a study published online June 6 in the Annals of Internal Medicine.

Kristina L. Bajema, M.D., from Oregon Health & Science University in Portland, and colleagues examined the effectiveness of nirmatrelvir-ritonavir and molnupiravir for outpatient treatment of COVID-19 in three retrospective target trial emulation studies involving nonhospitalized veterans at risk for severe COVID-19 who tested positive for severe acute respiratory syndrome coronavirus 2.

Overall, 87 percent of the participants were male, with a median age of 66 years; 18 percent were unvaccinated. The researchers found that the 9,607 patients treated with nirmatrelvir-ritonavir had lower 30-day risk for hospitalization compared with matched untreated controls (22.07 versus 30.32 per 1,000 participants) and a lower risk for death (1.25 versus 5.47 per 1,000 participants).

Reductions in 31- to 180-day incidence of death were seen among persons alive at day 31 (hazard ratio, 0.66), but not in hospitalization. Lower 30-day and 31- to 180-day risks for deaths were seen for molnupiravir-treated participants (3.14 versus 13.56 per 1,000 participants at 30 days; hazard ratio, 0.67 at 31 to 180 days), but not for hospitalization. No difference was seen in 30-day or 31- to 180-day risk for hospitalization or death between nirmatrelvir- or molnupiravir-treated participants.

"Nirmatrelvir-ritonavir seems to be an effective treatment for eligible persons with COVID-19 to reduce risk for short-term outcomes of severe COVID-19," the authors write. "The benefit of molnupiravir may be more limited."