Effects of subcutaneous naratriptan on systemic and pulmonary haemodynamics and coronary artery diameter in humans.

Naratriptan, an effective antimigraine agent, is a selective 5-hydroxytryptamine (5-HT1 )-receptor agonist with a pharmacologic profile similar to that of sumatriptan. The object of this study was to assess the haemodynamic effects of naratriptan in a clinical model previously applied to sumatriptan. Cardiac haemodynamics and coronary artery diameter were measured at baseline and after subcutaneous injections of placebo and naratriptan (1.5 mg, s.c.) in 10 patients undergoing diagnostic cardiac catheterisation. No statistically significant change in mean coronary artery diameter was observed after naratriptan [95% confidence interval (CI), -0.27-0.11 mm: p = 0.37]. Naratriptan injection was associated with statistically significant increases in systolic arterial pressure (95% CI, 7.6-22.0 mm Hg; p = 0.0015), total systemic vascular resistance (95% CI, 74-253 dyn/s/cc; p = 0.003), pulmonary artery systolic pressure (95% CI, 2.0-6.9 mm Hg; p = 0.003), pulmonary vascular resistance (95% CI, 3-34 dyn/s/cc; p = 0.025), and pulmonary artery wedge pressure (95% CI, 1.9-2.4 mm Hg; p = 0.009). Naratriptan, a selective 5-HT1-receptor agonist, caused a vasopressor response in the systemic and pulmonary arterial circulations but was not associated with coronary artery vasoconstriction.