Histamine H1 antagonists and clinical characteristics of febrile seizures

BACKGROUND: The purpose of this study was to determine whether seizure susceptibility due to antihistamines is provoked in patients with febrile seizures. METHODS: The current descriptive study was carried out from April 2009 to February 2011 in 250 infants and children who visited the Madinah Maternity and Children’s Hospital as a result of febrile convulsions. They were divided into two groups according to administration of antihistamines at the onset of fever. RESULTS: Detailed clinical manifestations were compared between patients with and without administration of antihistamines. The time from fever detection to seizure onset was significantly shorter in the antihistamine group than that in the nonantihistamine group, and the duration of seizures was significantly longer in the antihistamine group than in the nonantihistamine group. No significant difference was found in time from fever detection to seizure onset or seizure duration between patients who received a first-generation antihistamine and those who received a second-generation antihistamine. CONCLUSION: Due to their central nervous system effects, H1 antagonists should not be administered to patients with febrile seizures and epilepsy. Caution should be exercised regarding the use of histamine H1 antagonists in young infants, because these drugs could potentially disturb the anticonvulsive central histaminergic system.