Effect of subcutaneous sumatriptan on head temperature in migraines

Sumatriptan, a selective 5-hydroxy-triptamine (5-HT1) receptor agonist, has been used recently in the treatment of acute migraine. Some in vitro exper iments suggested that sumatriptan has vasoactive properties in vascular bed s distinct from cerebral circulation. In view of this we investigated the v ascular effects of the standard 6 mg subcutaneous (s.c.) dose of sumatripta n, on the surface areas of the head using thermography a simple and reliabl e method for detecting temperature changes. The head temperature of 127 pat ients (double-blind), 102 migraines (52 during headache attack and 50 heada che-free) and 25 healthy control subjects were evaluated using thermography in basal condition and 30, 60, 90, and 120 min after s.c. sumatriptan inje ction or placebo. During the entire observation period systemic blood press ure (SBP), heart rate (HR) and continuous electrocardiogram (ECG) were dete cted automatically. A significant head temperature decrease was observed af ter s.c. sumatriptan administration, in both healthy controls and migraine subjects; placebo administration did not show any change of temperature. In migraine patients during headache attack, head temperature reduction corre sponded to the relief of headache symptoms. This vasoconstrictor effect det ected with thermography is not isolated to cranial circulation but it is al so systemic. In fact, we observed a significant increase (p < 0.05) in both systolic and diastolic systemic blood pressure. No significant changes in heart rate and ECG abnormalities were otherwise detected. These findings su ggest that sumatriptan is effective in the treatment of migraine attack, bu t it must be used with caution in migraines with concomitant hypertension.