Effects of Beta Adrenergic Receptor Agonists and Antagonists in Diabetics with Symptoms of Postural Hypotension: A Double-Blind,Placebo-Controlled Study

Abstract

Eleven patients with hyperadrenergic diabetic postural hypotension and va gal neuropathy were treated in a double-blind, placebo-controlled study with different beta-agonists and antagonists. A single dose of the beta₂-agonist terbu taline (5 mg) and the beta₁ + 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 beta₁-antagonist with intrinsic sympathi comimetic activity (ISA) acebutolol (200 mg) and the beta₁-antagonist metopro lol (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 beta₁ + ₂-antagonist propranolol and the beta₁₊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.