A comparison of cilostazol and pentoxifylline for treating intermittent claudication

PURPOSE: We performed a randomized, double-blind, placebo-controlled, multi center trial to evaluate the relative efficacy and safety of cilostazol and pentoxifylline. PATIENTS AND METHODS: We enrolled patients with moderate-to-severe claudica tion from 54 outpatient vascular clinics, including sites at Air Force, Vet erans Affairs, tertiary care, and university medical centers in the United States. Of 922 consenting patients, 698 met the inclusion criteria and were randomly assigned to blinded treatment with either cilostazol (100 mg oral ly twice a day), pentoxifylline (400 mg orally 3 times a day), or placebo. We measured maximal walking distance with constant-speed, variable-grade tr eadmill testing at baseline and at 4, 8, 12, 16, 20, and 24 weeks. RESULTS: Mean maximal walking distance of cilostazol-treated patients (n = 227) was significantly greater at every postbaseline visit compared with pa tients who received pentoxifylline (n = 232) or placebo (n = 239). After 24 weeks of treatment, mean maximal walking distance increased by a mean of 1 07 m (a mean percent increase of 54% from baseline) in the cilostazol group , significantly more than the 64-m improvement (a 30% mean percent increase ) with pentoxifylline (P <0.001). The improvement with pentoxifylline was s imilar (P = 0.82) to that in the placebo group (65 m, a 34% mean percent in crease). Deaths and serious adverse event rates were similar in each group. Side effects (including headache, palpitations, and diarrhea) were more co mmon in the cilostazol-treated patients, but withdrawal rates were similar in the cilostazol (16%) and pentoxifylline (19%) groups. CONCLUSION: Cilostazol was significantly better than pentoxifylline or plac ebo for increasing walking distances in patients with intermittent claudica tion, but was associated with a greater frequency of minor side effects. Pe ntoxifylline and placebo had similar effects. Am J Med. 2000;109:523-530. ( C) 2000 by Excerpta Medica, Inc.