Drug therapy in intermittent claudication: an objective assessment of the effects of three drugs on patients with intermittent claudication.

It has been suggested that, by reducing the viscosity of blood, flow through capillaries is increased with consequent improvement in the symptoms of patients with peripheral vascular disease. We examined the effects of treatment with drugs purported to reduce blood viscosity to test the validity of this claim. Measurements of viscosity and the rate of blood flow to the leg were made in a group of patients before and after treatment with three different drugs--tetranicotinoylfructose (Bradilan), oxypentifylline (Trental) and cinnarizine (Stugeron). All patients had intermittent claudication in one leg and the distribution of arteriosclerosis was similar in each patient. After treatment there was little or no change in blood viscosity and no change in the rate of flow recorded in the symptomatic legs. We did not find any objective evidence to support the use of these drugs in patients with intermittent claudication.