Beta-adrenoceptor blockade, platelets, and rheologic factors.

Alterations in platelet function and other hemorheologic factors have been reported to occur in patients with migraine. The prophylactic treatment of migraine with beta blockers is at present well established, and non-selective as well as beta 1-selective beta blockers exert an effect. The aim of this presentation is to summarize how beta blockers, depending on their receptor selectivity, modulate platelet function and hemorheologic factors. We conclude that non-selective beta blockade increases factors, such as platelet aggregability, and decreases fibrinolytic activity compared with beta 1-selective blockade with metoprolol. These differences do not reflect on their migraine prophylactic effect and indicate that alterations in platelet function are not a primary cause of migraine: rather, they are epiphenomena.