The peripheral platelet count in response to intravenous infusion of salbutamol.

Five healthy male volunteers received i.v. infusions of salbutamol, a relatively selective beta-2-receptor-stimulating agent, in doses of 0.03, 0.06, 0.09 and 0.27 microgram X kg-1 X min-1 over a period of 6 min. At the three low doses the heart rate remained essentially unchanged and no significant decrease in the platelet count occurred. However, in response to 0.27 microgram X kg-1 X min-1 of salbutamol the heart rate increased by 25% over basal value (p less than 0.01) and a significant lowering (p less than 0.005) of the platelet count was obtained. The present findings suggest that the drop in the peripheral platelet concentration in response to adrenergic beta-receptor stimulation is mediated via beta-1-receptors.