Enkephalinase inhibition relieves pain syndromes of central dysnociception (migraine and related headache).

Normotensive and hypertensive headache sufferers were treated with D-phenylalanine, aprotinin or captopril--all inhibitors of endogenous opioid degradation. Inconsistent results were obtained using D-phenylalanine and aprotinin (acute administration at the start of a migraine attack). Satisfactory results were obtained by prophylactic treatment with captopril (an inhibitor of the angiotensin converting enzyme and of the dipeptidyl carboxypeptidase--an enkephalin inactivating enzyme) compared with conventional drugs such as methysergide, lisuride, pizotifen, clonidine and beta-blocking agents. Excellent results were obtained with captopril on patients suffering from headache and arterial hypertension who had experienced no relief from beta-blocking agents and clonidine. Captopril could thus be a drug of choice in the therapy of headache associated with essential hypertension.