Cilostazol: a novel treatment option in intermittent claudication

Cilostazol is a phosphodiesterase III inhibitor with antiplatelet, antithrombotic and vasodilatory effects. It raises plasma high-density lipoprotein cholesterol levels by approximately 10% and lowers plasma triglycerides by approximately 15%. Eight US/UK randomized, multicentre, double-blind, placebo-controlled trials lasting 12-24 weeks have been conducted with cilostazol 50, 100 or 150 mg twice daily in more than 2,000 patients with moderate to severe intermittent claudication. In constant- or variable-load treadmill tests, cilostazol increased maximal walking distance by 28-100%, and pain-free walking distance by 45-96%. Comparable changes for patients on placebo were -10 to 30% for maximal walking distance and 9 to 50% for pain-free walking distance. Responses were observed as early as the first observation point of 2 or 4 weeks and increased with time. The response was greater for 100 mg twice daily than for 50 mg twice daily. For the 100 mg twice daily dose, there was no evidence of a plateau in effect. In both the US and the UK, cilostazol is indicated to increase walking distance in patients with intermittent claudication. Cilostazol is generally well tolerated. In clinical trials, the most common adverse effects were headache, palpitation, tachycardia, abnormal stools and diarrhoea. Adverse events were generally mild to moderate in intensity.