Evaluation of a new alpha-blocking vasodilator agent (thymoxamine) in peripheral vascular disease.

Abstract

Abstract The effects on peripheral cutaneous blood-flow of the alpha-receptor blocking drug thymoxamine were measured by strain-gauge plethysmography in 58 subjects. The intravenous drug produced a substantial, though often transient, vasodilatation in the feet of normal subjects, and in most instances increased pedal blood-flow in non-sympathectomized patients with lower-limb arterial occlusions and healthy feet. In patients previously sympathectomized for either non-occlusive or occlusive disease of the lower limbs the effect of the drug was variable, even bringing about a reduction in pedal blood-flow in a number of cases. Intravenous thymoxamine regularly though briefly produced vasodilatation in the hands of patients sympathectomized for primary Raynaud'S disease, but the oral drug had no such action in most instances. It is concluded that systemic thymoxamine is unlikely to be of therapeutic benefit to the sympathecromized patient.