Effects of beta adrenergic receptor agonists and antagonists in diabetics with symptoms of postural hypotension: a double-blind, placebo-controlled study.

Eleven patients with hyperadrenergic diabetic postural hypotension and vagal neuropathy were treated in a double-blind, placebo-controlled study with different beta-agonists and antagonists. A single dose of the beta 2-agonist terbutaline (5 mg) and the beta 1 + 2-agonist orciprenaline (10 mg) did not reduce the fall in systolic pressure on standing up, despite a significant increase in both supine and standing heart rates. The beta 1-antagonist with intrinsic sympathicomimetic activity (ISA) acebutolol (200 mg) and the beta 1-antagonist metoprolol (50 mg) did not influence the fall in systolic pressure either, despite a significant decrease in supine and standing heart rates and disappearance of increase in heart rate on standing up. Only the beta 1 + 2-antagonist propranolol and the beta 1 + 2-antagonist with ISA pindolol (5 mg) could significantly reduce or practically abolish the fall in systolic and diastolic pressure on standing up. This was accompanied by a slight decrease of heart rates and disappearance of difference between supine and standing heart rates, as seen with the other beta-antagonists. Thus, only beta 2-blockade reduced or abolished the fall in systolic pressure on standing up in our patients. These data were confirmed by a three-week crossover trial in 10 of these patients.