Effects of atenolol and pindolol on the hypokalaemic and cardiovascular responses to adrenaline infusion.

To investigate if the intrinsic sympathomimetic activity of pindolol could modify its beta-blocking effects on the responses to an adrenaline infusion, 10 healthy volunteers were studied. At an interval of 1-4 weeks each subject received pindolol and atenolol in randomized order before the infusion of adrenaline 0.06 microgram.kg-1.min-1. Pindolol prevented hypokalaemia and significantly decreased the heart rate during the adrenaline infusion. These effects were not observed after atenolol. The diastolic blood pressure was slightly increased during the infusion of adrenaline after pindolol, whereas it remained unchanged after atenolol.