[The H2-antagonist therapy withdrawal syndrome: the possible role of hyperprolactinemia].

Patients previously treated with H2-receptor blocking agents (cimetidine or ranitidine) exhibited a complex neurobehavioral and gastroenteric syndrome, including anxiety, insomnia, anorexia, growing thin, irritability, tachycardia, diarrhoea, nausea, vomiting, abdominal pain, headache, vertigo. These symptoms were dramatically reduced by administration of cimetidine or ranitidine, and reappeared with a new suspension of the therapy. The withdrawal syndrome from H2-receptor antagonists was reversed by treatment with domperidone (10 mg three times per day), a potent hyperprolactinaemic drug which does not cross the blood brain barrier. These results suggest that the drop in prolactin levels that occurs when cimetidine or ranitidine are suspended may contribute to the development of the withdrawal syndrome.