Safety profile of H1-antihistamines in pediatrics: an analysis based on data from VigiBase

Purpose: H1-antihistamines are commonly used in infants and children for the relief of histamine-mediated symptoms in a variety of conditions. Little is known about their safety profile in these patients. We performed a comparative analysis of the safety profiles of H1-antihistamines using data from the WHO database (VigiBase). Methods: We selected adverse drug reaction (ADR) reports on H1-antihistamines in children (0–16 years) up to June 2014 from VigiBase. ADRs were codified according to MedDRA terminology. The reporting odds ratios (RORs) with 95% confidence for drug-reaction pairs were calculated. Results: The analysis was performed on 8918 reports related to antihistamines, corresponding to 19503 drug reaction pairs for 68 different drugs. Most of reports involved children aged 2 to 6 years (32%) and 6 to 12 years (34%). Most reported drugs were cetirizine (1608 reports, corresponding to 18%), loratadine (16%), and diphenhydramine (10%). ADRs were classified as serious in 23% of cases, and 400 cases had a fatal outcome. We found a significant associations for several drug-reaction pairs such as levocetirizine and epilepsy (ROR, 6.57; 95% confidence interval [CI], 1.51–28.53) and chlorphenamine and toxic epidermal necrolysis (ROR, 7.29; 95% CI, 2.39–22.2). Conclusions: H1-antihistamines are among the most used drugs in pediatrics, also in an off-label manner. Our data highlights associations with serious and unexpected ADRs. Educative intervention to clinicians and parents are needed to help doctors to make proper choices on the drug treatment and for the early detection of ADRs to maximize the benefits and reduce the risk of ADRs in these patients.