Shy-Drager syndrome: diagnosis and treatment of cholinergic dysfunction.

Two patients with Shy-Drager syndrome demonstrated unusually widespread and unequivocal cholinergic dysfunction as well as the usual evidence of adrenergic insufficiency. Progressive constipation preceded impotence, nocturia, hesitancy in micturition, anhidrosis, orthostatic hypotension, and xerostomia. Nonautonomic neurologic signs appeared several years later. Cholinergic dysfunction involved eyes, lacrimal glands, salivary glands, heart, gastrointestinal tract, urinary bladder, and sweat glands. Subcutaneous administration of bethanechol chloride--a muscarinic receptor agonist--improved tearing, salivation, sweating, and gastrointestinal and bladder functions. Daily administration of this drug resulted in symptomatic improvement of the autonomic functions, and relapse followed discontinuation of treatment.