In the prophylactic phase of the treatment of migraine the use of beta-blocking agents has become quite prominent within the past few years.
The circulation is responsive in both the internal and the external carotid arteries to beta-adrenergic neuro-transmission. It is postulated that beta-blocking agents would be helpful in preventing vasoconstriction in the internal carotid arteries by inhibiting impulses to beta receptors in the brain; also it would prevent the excessive adrenergic vasodilation in the external carotid arteries. The beta-adrenergic blockade thus offers an approach to the control of arterial vasodilation during the migraine attack.
The purpose of this study is to determine the relative efficacy and safety of nadolol, a new beta-blocking agent, in reducing the frequency and or, the severity of migraine attacks as compared to placebo.
Nadolol competes specifically with beta-adrenergic receptor antagonists for available beta-receptor sites. This drug inhibits beta-1 receptors, which are located chiefly in the cardiac muscle, and beta-2 receptors, which are located chiefly in the bronchial and the vascular musculature. When access to beta-adrenergic receptor sites is blocked by nadolol, the chronotropic, inotropic, and vasodilator responses to beta-adrenergic stimulation are decreased proportionately. Nadolol has no intrinsic sympathomimetric activity, nor does it have an anesthetic-like membrane stabilizing action.
The results obtained in this study, which were very encouraging, are presented, along with the side effects, which were very minimal.