The neuroendocrine effects of sumatriptan, a specific ligand for 5-HT1-like receptors

A relationship between the serotoninergic and the opiatergic system in the pathogenesis of head pain is supported by several data. This study was carried out to investigate the neuroendocrine effects of sumatriptan, a specific serotonin agonist used in the treatment of migraine, on hypothalamic-pituitary-adrenal axis (PHA) hormones.

Two consecutive studies were performed. In study A, eight subjects received a subcutaneous (s.c.) injection of sumatriptan (6 mg). In study B, a further six subjects were randomized to receive either sumatriptan or placebo.

Healthy volunteers recruited within the staff (eight males and six females) were studied.

In study A, plasma cortisol and PRL were measured by direct RIA and beta-endorphin after extraction and chromatography. Samples were collected from 60 minutes before to 120 minutes after the administration of the drug, at 15-minute intervals. According to the data of the first study, in study B, in addition to cortisol and beta-endorphin, ACTH was also measured.

Significant increases in the mean beta-endorphin and cortisol concentrations were found in every subject receiving sumatriptan, while no significant changes were observed in prolactin plasma levels. Study B confirmed the activation of the pituitary-adrenal axis, additionally demonstrating the release of ACTH, and indicated that placebo has no effects.

Acute s.c. stimulation with sumatriptan activates the pituitary-adrenal axis.