Chronic effects of metoprolol and methyldopa on calf blood flow in intermittent claudication.

In a placebo-controlled double-blind study 14 hypertensive patients with intermittent claudication were treated with metoprolol (100-200 mg daily) and methyldopa (500-1000 mg daily) for 3 weeks and their effects on heart rate, blood pressure as well as on resting and hyperaemic calf blood flow and vascular resistance were compared. In their antihypertensive effect metoprolol and methyldopa did not differ significantly. In 23 diseased limbs the calf blood flow and vascular resistance remained unchanged at rest during the trial. The active drugs reduced hyperaemic flow (P less than 0.05). The peak flow was reduced by 20% (P greater than 0.01) with metoprolol and by 15% with methyldopa below the initial level and by 17% and by 12% below the level recorded on placebo, respectively. Neither of the drugs influenced vascular resistance during reactive hyperaemia. Thus, in patients with intermittent claudication antihypertensives should be used with care.