Acetaminophen prevents febrile seizure recurrence

Michael G Burke, MD

Acetaminophen is a safe antipyretic against febrile seizures (FSs) and has the potential to prevent FS recurrence during the same fever episode, a study in Japan found.

Investigators evaluated 423 children and infants aged 6 to 60 months who visited their hospital’s emergency department (ED) because of an FS, defined in Japan as a seizure accompanied by a temperature of 100.4°F or greater without central nervous system (CNS) infection. The children were divided into 2 groups, with 1 group immediately receiving a 10 mg/kg dose of rectal acetaminophen that was repeated every 6 hours until 24 hours after the onset of the FS, as long as the child’s fever remained higher than 100.4°F. Parents of children in the no-antipyretic group were instructed not to administer any antipyretics to their child for 24 hours after the FS. No participants received diazepam suppositories during the study period.

Overall, 16% of participants experienced FS recurrence during the same fever episode, all within 24 hours of the initial FS. The recurrence rate was significantly lower in the rectal-acetaminophen group than in the no-antipyretics group: 9.1% versus 23.5%, respectively.

In children aged 6 to 21 months, recurrence rate was 13.2% in the rectal-acetaminophen group and 24.3% in the no-antipyretics group. The difference in recurrence rates between the 2 groups was even more striking among children aged 22 to 60 months: 4.1% versus 22.6% for the rectal-acetaminophen group and no-antipyretic group, respectively.

Investigators noted no serious complications related to acetaminophen, such as hypotension, hypothermia, or anaphylaxis. Although FS patients with diarrhea were excluded from randomization, investigators compared these children’s seizure recurrence rate with those of children in the trial, finding that the rate in those with diarrhea was considerably higher-35%-than the rates in both the rectal-acetaminophen group and the no-antipyretics group.

A data analysis that accounted for other clinical variables found that rectal acetaminophen was the largest contributor to prevention of FS recurrence during the same fever episode (Murata S, et al. Pediatrics. 2018;142[5]:e20181009).

Thoughts from Dr Burke

At first, I thought that this study was an evaluation of prophylactic acetaminophen after a first febrile seizure. It is not. Children in the treatment group were given acetaminophen each 6 hours only if they had continued fever. Unlike in some previous studies, this approach worked in reducing subsequent seizures during the same illness. I can find no other studies that support prophylactic use of antipyretics during the duration of a febrile illness after a seizure, and a 2008 American Academy of Pediatrics (AAP) clinical practice guideline does not recommend this approach (Pediatrics. 2008;121[6]:1281-1286).