Therapy of migraine by modulating dopamine hypersensitivity: its effect on mood and pain

Clinical and pharmacological evidences support the hypothesis of a hypersensitivity of dopamine (DA) receptors in migraine patients. The aim of our single-blind and placebo-controlled study is to evaluate the presence of this hypersensitivity and to desensitize the DA system with apomorphine, a classical DA receptor agonist. We studied six patients suffering from migraine without aura resistant to the prophylactic treatment and with high frequency of attacks. In these patients, we first tested individual sensitivity by a single i.m. low dose of apomorphine to assess the lowest effective dose to be administered s.c. in continuous infusion without side-effects. We used the response of growth hormone (GH) to apomorphine as a marker of DA2-receptor function. Clinical evaluation, blood pressure and heart rate were recorded before placebo or apomorphine administration and monitored every 15 min for 1 h after each injection. The treatment consisted of the continuous subcutaneous infusion of apomorphine for three weeks at the dosage previously assessed by the test. No difference in blood pressure and heart rate was found during test and treatment. The treatment was effective in reducing the frequency and the severity of migraine attacks.