Causes of Intermittent Claudication

Intermittent claudication is most often caused by atherosclerosis in the arteries in the legs. The most frequently affected artery is the popliteal artery, which leads off from the femoral artery in the thigh and continues below the knee where it branches off and carries blood to the muscles in the leg and foot. Atherosclerosis (commonly called hardening of the arteries) is also the major process leading to heart disease. Intermittent claudication is very rare in younger people.

Risk Factors for Intermittent Claudication

Intermittent claudication often accompanies coronary artery disease, and is found in about 11% of people over 50 years old. Men are at higher risk than women up until older ages when women catch up. The major risk factors for heart disease (smoking, hypertension, increasing age, and diabetes) are also the most important risk factors for intermittent claudication. People in northern regions tend to have a higher risk than those in southern areas.

Consequences of Intermittent Claudication

Because intermittent claudication is caused by atherosclerosis, patients with this condition have double the risk for death from heart attack and stroke. The pain itself clears up in 40% of patients, although this does not eliminate any accompanying heart risks. However, damage in the leg from oxygen loss can progress in 10% to 20% of patients to the point where 7% require amputation within five years of onset.

How Is Intermittent Claudication Treated?

The first step in treating intermittent claudication for most patients is to reduce their risk for heart attack and stroke with a healthy diet and exercise. Smokers should quit. Studies are underway to determine if taking antioxidant supplements (vitamins E and C), cholesterol-improving drugs, or standard blood thinners (warfarin) can help people with intermittent claudication.

Exercise. Exercise is the most important life-style measure for relieving pain. One analysis of a number of studies reported that physical training was more effective than the standard medications, pentoxifylline and nafronyl, in increasing pain-free walking distance. Subjects exercised for three to six months.

Medications

Vasoactive Drugs. Drugs that improve blood flow, called vasoactive agents, are often used to relieve intermittent claudication. The standard agent in the US is pentoxifylline (Trental). Pentoxifylline reduces the sticky properties of blood, improving its flow. Cilostazol (Pletal) is a newer treatment approved in the US that reduced blood clotting factors to improve blood flow. It is effective but may have potentially serious side effects in patients with heart failure. The most common side effects for both include nausea (in nearly a third of those taking pentoxifylline), heartburn and gas, dizziness, headache, blurred vision, and flushing. Both drugs also may enhance the effects of other blood-thinning agents. More research is needed on the side effects of both these agents. Nafronyl is a drug available in Europe for intermittent claudication. It enhances the ability for damaged muscle tissue to absorb oxygen from blood. Both cilostazol and nafronyl may be more effective than pentoxifylline in increasing walking distance.

Ginkgo Biloba. One analysis of eight studies reported that the herbal remedy ginkgo biloba has some modest effect on pain-free walking. The drug has blood-thinning properties and is available over the counter. It should be strongly noted that herbal remedies are not regulated and standards are not guaranteed. In addition, all agents that are effective are also most likely to have side effects, even so-called natural ones. Ginkgo has a small risk for bleeding, which may increase in combination with other medications, such as warfarin or high-doses of vitamin E.

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