The U.S. Food and Drug Administration (FDA) announced it’s approval of Xofluza (baloxavir marboxil), a single-dose, oral prescription flu treatment. On Wednesday, Oct. 24., Xofluza became the first new flu treatment approved by the FDA in almost two decades. 

New Flu Treatment: When to Use It, Where to Buy It

The new flu medication is intended for patients who are 12 years of age or older, who have had symptoms for less than 48 hours. When patients with the flu are treated within 48 hours of becoming sick, antiviral drugs can reduce symptoms and duration of illness, according to the FDA.

Genentech, the U.S.-based distributor of Xofluza, says the new drug will be available to those affected by the flu in the United States by prescription in the coming weeks. The drug will cost $150.

However, patients with commercial insurance that cover the cost of the drug in addition to using a coupon available on Genentech website could pay as little as $30.

Xofluza Discovered in Japan, Approved After Clinical Trial

Xofluza was discovered by Japan's Shionogi & Co., Ltd. and was developed globally by Shionogi and the Roche Group. The drug was approved in February by the Japanese Ministry of Health, Labour and Welfare for the treatment of influenza types A and B in both adult and pediatric patients. 

Two clinical trials with 1,832 patients proved the safety and efficacy of Xofluza in the eyes of the FDA. In both experiments, the Xofluza patients' symptoms eased in a shorter amount of time compared to placebo patients. The most common side effects of Xofluza included diarrhea and bronchitis.