Efficacy and safety of cilostazol, a novel phosphodiesterase inhibitor in patients with intermittent claudication.

Pharmacotherapy is limited for the relief of intermittent claudication (IC), a common manifestation of peripheral arterial disease (PAD). Pentoxyfylline, the only current pharmacological therapy for IC, has been shown to have similar efficacy as placebo. Cilostazol, a new phosphodiesterase III (PDE III) inhibitor, is a potent inhibitor of platelet aggregation with vasodilatory, antithrombotic, antiproliferative and positive lipid-altering effects. To evaluate the efficacy and safety of cilostazol for the treatment of IC in Indian patients, 123 patients were selected from 6 centres in India. The patients, aged 58-73 years, with the diagnosis of stable moderate-to-severe IC received cilostazol 100/50 mg twice daily for a period of 12 weeks. Primary efficacy measures included initial claudication distance (ICD) and absolute walking distance (ACD) by treadmill testing and ankle-brachial index (ABI) using Doppler ultrasonography-measured systolic pressures. Secondary efficacy outcomes included subjective assessment of symptom improvement by patient and investigator and estimation of lipid values. Adverse events were monitored throughout the study. Laboratory investigations were carried out at baseline and end of study. At the end of week 12 of cilostazol therapy, there was a significant improvement in the raw walking distances (ICD and ACD). Percentage change in ICD and ACD was 46.77% and 64.5%, respectively, at the end of study. There was a significant increase (32.7%) in the ABI by the end of study period. According to patient and investigator assessment of symptoms, 58-60% of the subjects showed significant improvement to complete resolution of claudication symptoms by the end of 12 weeks of therapy. In addition, there was a significant increase of 20.24% in the mean plasma HDL-cholesterol levels and a decrease of 29.55% in the mean plasma triglyceride concentrations by the end of study period. Headache, diarrhoea, palpitation and dizziness were the commonly reported adverse effects during the study. No adverse effect led to discontinuation of therapy. The present study suggests that cilostazol is an effective therapeutic option with an acceptable tolerability profile for the treatment of IC in patients with PAD.