Neuropsychiatric manifestations associated with azithromycin in two brothers.

BACKGROUND: Neurologic adverse events reported in premarketing clinical trials of azithromycin have been mild, occurring in less than 1% of the patients, and include dizziness, headache, vertigo, and somnolence. Serious adverse neuropsychiatric effects of azithromycin have never been reported in the pediatric population and only seldom in adults. CASE REPORT: We report two brothers aged 6 and 15 years with severe and prolonged complex neuropsychiatric manifestations associated with azithromycin treatment. Both brothers experienced visual and auditory hallucinations, and one brother additionally experienced multiple partial complex seizures, severe headaches, and recurrent cortical blindness. All symptoms commenced within 24 h after the initial dose of azithromycin and resolved slowly, within 2-4 weeks. DISCUSSION: Possible genetic and environmental explanations are discussed, such as polymorphism in uptake of efflux transporters at different levels, particularly at the blood brain barrier level.