Story highlights The new antiviral medication is intended for patients 12 and older

The medicine is given as a single, oral dose

(CNN) Flu sufferers now have a new option for relieving symptoms. Xofluza (baloxavir marboxil), a single-dose, oral prescription drug, was approved by the US Food and Drug Administration on Wednesday. The antiviral is the first new flu treatment approved by the FDA in nearly 20 years, FDA Commissioner Dr. Scott Gottlieb said in a statement.

"With thousands of people getting the flu every year, and many people becoming seriously ill, having safe and effective treatment alternatives is critical," said Gottlieb.

The pill is intended for patients who are 12 or older and who have had symptoms for no more than 48 hours. When patients with the flu, a respiratory illness, are treated within 48 hours of becoming sick, antiviral drugs can reduce symptoms and duration of illness, according to the FDA.

Two clinical trials with 1,832 patients proved the safety and efficacy of Xofluza when taken within 48 hours of experiencing flu symptoms, according to the FDA statement. In both experiments, the Xofluza patients' symptoms eased in a shorter amount of time compared to placebo patients. However, no difference in symptom duration was seen between patients who received Xofluza and those who received another flu drug.

The most common side effects of Xofluza included diarrhea and bronchitis, the government agency reported.

Read More