Metoprolol excretion into breast milk.

Abstract

Following labetalol administration there was a significant increase in plasma glucose concentration with a peak at 10 min after which the concentration declined to baseline levels by 45 min.No increase occurred in plasma glucose concentrations following hydrallazine, phentolamine or placebo (Table 1).It is unlikely that the increase in plasma glucose concentration that followed administration of labetalol is due to its a-and JJ-antagonist activity.fiadrenoceptor blocking drugs inhibit glycogenolysis and may precipitate hypoglycaemia.a-adrenoceptor blockade by phentolamine in the present experiment failed to increase plasma glucose during the period of observation.The increase in plasma glucose following labetalol was not secondary to the hypotensive effect of the drug as it did not occur when the blood pressure was reduced to the same extent with hydrallazine.It is suggested that labetalol may cause temporary increase in plasma glucose by promoting glucogenolysis by fl2-adrenoceptor agonist action.