The effect of cimetidine and propantheline on the symptoms of a patient with systemic mastocytosis.

A 24 year old white woman with a lifelong history of systemic mastocytosis and symptoms of diarrhea and flushing was demonstrated to have a normal gastric analysis and inconsistent steatorrhea. She responded well to oral cimetidine therapy for 11 months. A symptomatic recurrence was controlled with the addition of propantheline. Gastric secretory studies demonstrated cimetidine suppression of both basal acid and basal pepsin secretion, as well as maximal pentagastrin-stimulated acid secretion; suppression of stimulated pepsin secretion was minimal. The combination of cimetidine and propantheline markedly suppressed both peak acid and peak pepsin secretion in response to pentagastrin stimulation. These data support a dominant role of cholinergic mechanisms in the control of gastric pepsin secretion; additional data obtained with maintenance of constant intragastric pH are required for further clarification.