Association of severe abnormal behavior and acetaminophen with/without neuraminidase inhibitors

Even though abnormal behavior related with influenza and neuraminidase inhibitors (NI) has been discussed, the risks of acetaminophen and co-administration of NI and acetaminophen have not been examined. This study assesses those risks.

All cases of patients with influenza who present with severe abnormal behavior are reported by physicians of all clinics and hospitals throughout Japan. The numbers of people diagnosed as having influenza, whether prescribed NI and acetaminophen or not, were extracted from the National Database of Electronic Medical Claims (NDBEMC). The study period was from September 2009 to March 2016.

We found two consistent results among four combinations of age class and severity. The one was that patients who did not use NI or acetaminophen showed significantly higher incidence of abnormal behavior than zanamivir with acetaminophen, another one was that patients with oseltamivir only has higher incidence than zanamivir with acetaminophen. Concerning about acetaminophen, the use of it significantly decrease risk for severe and the most severe instances in 5-9-year-old patients with laninamivir and the severe instances in 10-19-year-old patients with zanamivir.

We also demonstrated that acetaminophen alone or co-administered with NI does not seem to raise the risk of abnormal behavior in influenza patients.