Anticholinergic effects (constipation, xerostomia, blurred vision, urinary retention) limited (use with caution in decreased gastrointestinal motility, paralytic ileus, urinary retention, benign prostatic hypertrophy, xerostomia, or visual problems, and in patients intolerant to anticholinergic agents, including tricyclic antidepressants, phenothiazines, or cyproheptadine). May cause CNS depression. Use with caution in cardiovascular disease, diabetes mellitus, narrow-angle glaucoma (may be exacerbated by cholinergic blockade), and in hepatic or renal impairment. Not for use in acute treatment of migraine attacks. Use with caution in myasthenia gravis (may be exacerbated by cholinergic blockade), and in obese patients. Effects may be potentiated when used with other sedative drugs or ethanol. Avoid abrupt discontinuation. Some patients may develop tolerance.