Severe hypoglycaemia during physical exercise and treatment with beta-blockers.

Despite important metabolic effects beta-blocking agents are usually tolerated, but during metabolic stress important perturbations occur. For instance, treatment with a non-selective beta-blocker to a slower rate of recovery from insulin-induced hypoglycaemia.1 Similarly, blood glucose concentrations are more rapidly during prolonged physical exercise during treatment with a-blocker.2 Serious hypoglycaemia has occurred during prolonged in patients receiving treatment with propranolol3 and.4 report on a patient treated with alprenolol, a non-selective-blocker with intrinsic sympathomimetic activity, who developed hypoglycaemia during endurance exercise.