Patients >40 yr particularly w/ severe heart disease, HTN, ulcerative colitis, ileus, chronic lung disease, hyperthyroidism, autonomic neuropathy, hepatic or renal disease or prostatic hypertrophy, esophageal reflux or hiatus hernia. Avoid abrupt change in dose. Debilitated patients. Chronic pulmonary disease. May precipitate acute glaucoma in susceptible patients. Myasthenia gravis; cardiac insufficiency or failure, MI or ischemia. Development of angina in patients w/ cardiac problems; arrhythmias in adult & ped. Development of ventricular fibrillation. Pregnancy & lactation. Childn & infants. Elderly.