Neuroendocrine effects of sumatriptan.

The neuroendocrine effects of the 5-HT receptor agonist, sumatriptan (6 mg subcutaneously), were studied in 11 healthy male subjects using a placebo-controlled, cross-over design. Compared to placebo, sumatriptan significantly lowered levels of plasma prolactin but increased those of plasma growth hormone. There was no effect on plasma cortisol concentrations. The neuroendocrine effects of sumatriptan differ from those of previously described 5-HT-receptor agonists, and may be a consequence of selective activation of 5-HT1D or 5-HT1B receptors. However, the present data cannot exclude the possibility that the neuroendocrine changes reflect nonspecific stress responses or changes in pituitary blood flow.