Cilostazol: a novel treatment option in intermittent claudication

Area of Science:

• Pharmacology
• Vascular Medicine
• Clinical Trials

Background:

• Cilostazol is a selective phosphodiesterase III inhibitor.
• It possesses antiplatelet, antithrombotic, and vasodilatory properties.
• Cilostazol also influences lipid profiles, increasing HDL and decreasing triglycerides.

Purpose of the Study:

• To evaluate the efficacy of cilostazol in improving walking distance in patients with intermittent claudication.
• To assess the dose-response relationship and onset of action for cilostazol.
• To determine the safety and tolerability profile of cilostazol in this patient population.

Main Methods:

• Eight randomized, multicenter, double-blind, placebo-controlled trials were conducted in the US and UK.
• Over 2,000 patients with moderate to severe intermittent claudication participated.
• Patients received varying doses of cilostazol (50, 100, or 150 mg twice daily) or placebo for 12-24 weeks.
• Treadmill tests (constant- and variable-load) were used to measure walking distances.

Main Results:

• Cilostazol significantly increased maximal walking distance by 28-100% and pain-free walking distance by 45-96%.
• Placebo groups showed smaller improvements (-10 to 30% maximal, 9 to 50% pain-free).
• Responses were evident early (2-4 weeks) and increased over time, with 100 mg twice daily showing greater efficacy than 50 mg twice daily.

Conclusions:

• Cilostazol is indicated for increasing walking distance in patients suffering from intermittent claudication.
• The drug is generally well-tolerated, with common side effects including headache, palpitations, and gastrointestinal disturbances.
• The 100 mg twice daily dosage demonstrated effectiveness without reaching a plateau, suggesting sustained benefit.