Can Antihistamines Trigger Seizures in Young Kids?

TOPLINE:

First-generation antihistamines are linked to a 22% higher risk for seizures in children, new research shows. The risk appears to be most pronounced in children aged 6-24 months.

METHODOLOGY:

• Researchers in Korea used a self-controlled case-crossover design to assess the risk for seizures associated with prescriptions of first-generation antihistamines.
• They analyzed data from 11,729 children who had a seizure event (an emergency department visit with a diagnosis of epilepsy, status epilepticus, or convulsion) and had previously received a prescription for a first-generation antihistamine, including chlorpheniramine maleate, mequitazine, oxatomide, piprinhydrinate, or hydroxyzine hydrochloride.
• Prescriptions during the 15 days before a seizure were considered to have been received during a hazard period, whereas earlier prescriptions were considered to have been received during a control period.
• The researchers excluded patients with febrile seizures.

TAKEAWAY:

• In an adjusted analysis, a prescription for an antihistamine during the hazard period was associated with a 22% higher risk for seizures in children (adjusted odds ratio, 1.22; 95% CI, 1.13-1.31).
• The seizure risk was significant in children aged 6-24 months, with an adjusted odds ratio of 1.49 (95% CI, 1.31-1.70).
• For older children, the risk was not statistically significant.

IN PRACTICE:

“The study underscores a substantial increase in seizure risk associated with antihistamine prescription among children aged 6 to 24 months,” the authors of the study wrote. “We are not aware of any other studies that have pointed out the increased risk of seizures with first-generation antihistamines in this particular age group…. The benefits and risks of antihistamine use should always be carefully considered, especially when prescribing H1 antihistamines to vulnerable infants.”

The findings raise a host of questions for clinicians, including how a “relatively small risk” should translate into practice, and whether the risk may be attenuated with newer antihistamines, wrote Frank Max Charles Besag, MB, ChB, with East London NHS Foundation Trust, in the United Kingdom, in an editorial accompanying the study. “It would be reasonable to inform families that at least 1 study has suggested a relatively small increase in the risk of seizures with first-generation antihistamines, adding that there are still too few data to draw any firm conclusions and also providing families with the information on what to do if the child were to have a seizure.” 

SOURCE:

Seonkyeong Rhie, MD, and Man Yong Han, MD, both with the Department of Pediatrics at CHA University School of Medicine, in Seongnam, South Korea, were the corresponding authors on the study. The research was published online on August 28, 2024, in JAMA Network Open.

LIMITATIONS:

The researchers lacked details about seizure symptoms, did not include children seen in outpatient clinics, and were unable to verify the actual intake of the prescribed antihistamines. Although second-generation antihistamines may be less likely to cross the blood-brain barrier, one newer medication, desloratadine, has been associated with seizures.

DISCLOSURES:

The study was supported by grants from the Korea Health Technology Research and Development Project through the Korea Health Industry Development Institute, the Ministry of Health and Welfare, Republic of Korea.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.