The Ministry of Food and Drug Safety said Wednesday that it has added sleep disorders to the side effects of influenza medication oseltamivir, also known as Tamiflu.

The change to the warning label comes as a response to a series of reported cases regarding Tamiflu in Korea from 1989 to 2016. The ministry will distribute leaflets regarding oseltamivir’s effects and side effects to public health institutions nationwide.

“Although the causal relationship is unclear, children and adolescents who have taken the drug have reported neuropsychiatric side effects such as convulsions and delirium,” a ministry official said. “We advise parents to make sure the patients are not left alone for at least two days and look out for potential side effects.”

Oseltamivir is an antiviral drug used to treat and prevent influenzas A and B. The U.S. Centers for Disease Control and Prevention (CDC) has advised clinicians to prescribe the drug to high-risk individuals but not the general population within 48 hours of the first symptom.

There are currently 123 such products sold in Korea.

The ministry recommends infected patients take the drug within 48 hours after the first symptoms for effective treatment as propagation occurs 72 hours after initial infection.

Patients who have compromised kidney functions, liver disease, diabetes or other chronic illnesses should also control their drug dosage for safe treatment, the ministry said. Doctors may prescribe the drug to infants two weeks after birth.

Common side effects include vomiting, nausea, diarrhea, dizziness, and indigestion.

The ministry recommends individuals take the drug twice a day for five days for treatment, and once a day for 10 days for prevention. Patients should take the entire course of medication even after seeing improved symptoms, the ministry added.