THE HEMODYNAMIC-EFFECTS OF SUBCUTANEOUS SUMATRIPTAN, A 5HT(1)-RECEPTOR AGONIST

Aims Previous in vivo studies with sumatriptan, a 5HT(1)-receptor agon ist, have demonstrated vasopressor responses in the pulmonary and syst emic arterial circulation. Pulmonary artery wedge pressure (PAWP) also increases after sumatriptan injection, raising the possibility of an additional venoconstrictive action or a negative inotropic effect. The mechanism for the rise in PAWP was investigated in the study. Methods Ten patients undergoing diagnostic coronary arteriography underwent h aemodynamic monitoring. Results There was a significant rise (P<0.05) in systemic and pulmonary arterial pressure and total systemic and pul monary vascular resistance. There was a similar rise (P<0.05) in PAWP and left ventricular end diastolic pressure (LVEDP). There was no chan ge in cardiac output nor in peak rate of left ventricular pressure ris e (dP/dt). Conclusions The sumatriptan induced rise in PAWP and LVEDP appears consequent upon increased afterload although a negative inotro pic effect cannot be excluded.