Infantile spasms associated with a histamine H1 antagonist.

Some anti-allergic agents act as histamine H1 antagonists and induce seizure discharges in epileptic patients. Of these agents, ketotifen has an especially potent effect. We have experienced 2 cases of 4-month-old boys who developed infantile spasms 8 to 10 days after ketotifen administration. They showed almost the same clinical course with regard to their age, the interval between ketotifen administration and the onset of seizures, their symptoms and EEG abnormalities. These cases suggest that the administration of ketotifen to young infants may be hazardous with regard to inducing infantile spasms.