HEALTH CARE

New Pill Helps COVID Smell and Taste Loss Fade Quickly

The antiviral drug ensitrelvir, which has not been approved outside of Japan, shortens sensory problems

By Mariana Lenharo, Nature magazine on October 18, 2023

New clinical-trial data suggest that an antiviral pill called ensitrelvir shortens the duration of two unpleasant symptoms of COVID-19: loss of smell and taste. The medication is among the first to alleviate these effects and, unlike other COVID-19 treatments, is not reserved only for people at high risk of severe illness.

Early in the pandemic, roughly 40–50% of people with COVID-19 experienced impaired smell or taste. The antiviral drug molnupiravir speeds recovery of these senses, but generally only the most vulnerable people can take it.

That is not true for ensitrelvir. In Japan, where it received emergency approval last year, the drug is available to individuals with mild to moderate symptoms, regardless of their risk factors. Its developer, Shionogi in Osaka, Japan, is continuing to conduct clinical trials of the drug, which has not yet been approved outside Japan.

In one such trial, people with mild or moderate COVID-19 symptoms were given either 125 or 250 milligrams of ensitrelvir or a placebo. At the start of the study, 20% of participants reported some level of smell or taste loss. After the third day of treatment, the proportion of participants reporting such symptoms in the ensitrelvir groups started dropping more sharply than did the proportion in the placebo group. At day seven, the percentage of participants with smell or taste loss was 39% lower in the group taking 250-milligram pills than in the placebo group. Three weeks after treatment began, all groups reported similar symptom scores.

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