Effect of cardioselective and non-selective beta-blockade on the hypoglycaemic response in insulin-dependent diabetics.
The response to intravenous insulin was studied in seven diabetics after a dose of placebo, propranolol (40 mg), or metoprolol (50 mg). Two of the seven subjects also had a week's course of each of the same agents taken three times daily. Neither of the beta-blockers potentiated the effect of insulin as judged by the rate of reduction in blood-glucose. However, blood-glucose recovery was reduced significantly by propranolol, but not significantly by metoprolol. Propranolol caused severe bradycardia and raised diastolic blood-pressure during hypoglycaemia; these effects were milder with metoprolol. Propranolol inhibited the free-fatty-acid levels after hypoglycaemia to a greater extent than did metoprolol. The results strongly suggest that propranolol (and presumably other non-selective beta-blockers) is hazardous in subjects prone to hypoglycaemia. When diabetics require beta-blockade a cardioselective beta 1-blocker should be used.
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure / Q000187:drug effects; D001919:Bradycardia / Q000139:chemically induced; D002986:Clinical Trials as Topic; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000503:physiopathology*; D003971:Diastole / Q000187:drug effects; D005227:Fatty Acids / Q000037:antagonists & inhibitors; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy*; D007003:Hypoglycemia / Q000139:chemically induced; D007275:Injections, Intravenous; D007328:Insulin / Q000008:administration & dosage*; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage*; D008875:Middle Aged; D010919:Placebos; D011412:Propanolamines / Q000008:administration & dosage*; D011433:Propranolol / Q000008:administration & dosage*; D011674:Pulse / Q000187:drug effects; D012107:Research Design
D001786:Blood Glucose; D005227:Fatty Acids; D007328:Insulin; D010919:Placebos; D011412:Propanolamines; D011433:Propranolol; D008790:Metoprolol