Effects of metoprolol and propranolol on theophylline elimination.

The effects of beta adrenergic blockade on theophylline elimination were studied in nine nofmal subjects. Oral propranolol, 40 mg every 6 hr, induced a fall in theophylline clearance from 0.0464 +/- 0.0294 +/- 0.0129 l/kg/hr (p < 0.001). Oral metoprolol, 50 mg every 6 hr, did not reduce theophylline clearance in the group as a whole but had reducing effect intermediate to that of propranolol on theophylline clearance in some smokers whose theophylline clearance was high initially. Beta adrenergic blockade may reduce theophylline clearance, particularly in subjects whose theophylline metabolism has been induced by cigarette smoking.