Cerebrovascular effects of cilostazol in patients with atherosclerotic disease

Cilostazol is a potent selective inhibitor of phosphodiesterase-3 of proven efficacy in intermittent claudication. It has antiplatelet effect and produces vasodilatation in several vascular territories. This drug has been approved in some countries for the prevention of recurrence of cerebral infarction. Limited data in patients with cerebral infarcts suggest improvement in cerebral blood flow. Dilatation of cerebral vessels with carbon-dioxide challenge can be assessed by transcranial Doppler technique. The percentage increase in blood flow velocity is called cerebral vasomotor reactivity (CVR).

In this investigation we sought to measure CVR before and after oral administration of cilostazol.

We studied patients with risk factors for atherosclerosis before they received cilostazol (100 mg twice daily) for intermittent claudication. CVR was assessed by measuring bilateral middle cerebral artery blood flow velocity during normoventilation and after 3 minutes of breathing 8% carbon dioxide. One average value was obtained from each patient. CVR was measured the day before cilostazol first dose, at 1 month, and 3 to 6 months later.

We examined 9 patients (8 men and 1 woman) aged 67.6 +/- 8.4 years. All patients had hypertension, 5 had diabetes, 4 were smokers, 5 had high cholesterol levels, and 4 had coronary artery disease. CVR was 54.4 +/- 14.4% at baseline, and increased to 64.2 +/- 18.6% after 1 month (P < .05) and to 67.1 +/- 13.3% at 3 to 6 months later (P < .01).

Our findings suggest that cilostazol increases CVR in patients with atherosclerotic disease.