Molnupiravir, which prevents the novel coronavirus from multiplying in the body, was given the green light under a fast-track process after MSD K.K., the Japanese arm of Merck, applied in early December to produce and sell the drug in Japan.
In an interim report on clinical trials in Japan, Europe, and the United States, Merck initially reported that Molnupiravir halves the risk of hospitalization and death.
The Japanese subsidiary has said that molnupiravir is also likely effective against the Omicron variant of the virus. Patients 18 or older with mild symptoms will be able to take the pill twice a day for five days.
Prime Minister Fumio Kishida said that 200,000 doses of the pill would be delivered nationwide from this weekend if approved. The government has already agreed with Merck on the procurement of 1.6 million doses.
Health minister Shigeyuki Goto said the drug was expected to be available at medical institutions as early as Monday. The ministry will work with drugstores to enable the treatment to be taken at home to reduce contact between patients and others.
Molnupiravir, also approved in Britain in November, has drawn attention as the world’s first approved Covid-19 treatment that can be taken orally. But British regulators have not recommended its use for pregnant women, and it is not approved for children.