Combination H1 and H2 receptor antagonist therapy in diabetic autonomic neuropathy

Autonomic neuropathy occurs frequently in diabetic patients but is seldom effectively treated. In our patient, a 34-year-old man with poorly controlled type 1 diabetes and autonomic neuropathy manifested by postural hypotension and diarrhea, treatment with diphenhydramine and cimetidine (H1 and H2 histamine antagonists, respectively) markedly improved the hypotension and diarrhea and led to better blood glucose control.