Downbeat nystagmus due to ranitidine in a pediatric patient

Abstract Background Ranitidine has not been considered as a potential cause of ocular movement conditions. However, it is known that the vestibular nucleus complex, that has a key role in gaze control and vestibule-ocular reflexes, receives hypothalamic histaminergic innervations. Some studies reported the effect of ranitidine blocking the excitatory responses of vestibular nuclei neurons to histamine. Case report We report the first case of a downbeat nystagmus secondary to ranitidine in an infant. A 3-month-old female developed a downbeat gaze after starting treatment with ranitidine for a pediatric gastroesophageal reflux disease. Microbiological test were negative and neuroblastoma evaluation was normal. Conclusion As ranitidine is widely prescribed in the pediatric population, clinicians should be aware of its potential to cause ocular movements disorders.