In January 1999, the U.S. Food and Drug Administration approved cilostazol (brand name: PLETAL) for the management of intermittent claudication, a condition in which pain develops in the lower legs during walking and sometimes at rest. It results from narrowing of the arteries that supply the leg muscles with blood and oxygen.
Cilostazol does not cure intermittent claudication but rather reduces the pain so that patients can walk longer before developing pain. In 8 studies, the average improvement in walking distance was 28 to 100% for patients who took cilostazol as compared with -10 to 30% for patients who took a placebo ("sugar pill").
It is not completely known how cilostazol works. Its primary action is to expand the arteries going to the legs, increasing the flow of blood and oxygen to the muscles. It also reduces the ability of blood to clot.
Until now, pentoxifylline (TRENTAL) was the only drug approved for the management of intermittent claudication. TRENTAL improves blood flow by making it easier for red blood cells that carry oxygen to travel through arteries and by decreasing the "stickiness" (viscosity) of blood.