The effects of BTS 49465 on blood pressure and peripheral arteriolar and venous tone in normal volunteers.

The pharmacokinetics and cardiovascular effects of a new vasodilator, BTS 49465 (7-fluoro-1-methyl-3-methylsulphinyl-4-quinolone) were evaluated in a double-blind placebo-controlled manner in a group of normal male volunteers. Forearm vascular resistance and forearm venous tone were measured by venous occlusion plethysmography using mercury-in-rubber strain gauges, supine, and in response to lower body negative pressure. Systemic arterial pressure was also measured. Dose-dependent reductions in blood pressure were observed both supine and in response to lower body negative pressure. Measurements of forearm vascular resistance and forearm venous tone suggested the drug caused both arteriolar and venous vasodilatation. Plasma level measurements indicated that the active metabolite of BTS 49465 had a prolonged half-life. BTS 49465 is a mixed arteriolar and venous vasodilator which may be suitable for once-daily administration. Measurement of limb vascular tone is a useful means of evaluating the effects of vasodilators.