Drug Profile

Pentoxifylline was approved by the FDA in 1984 to reduce the symptoms of intermittent claudication, a chronic, debilitating, non-life-threatening disorder that causes pain, aches, cramping, numbness or a sense of fatigue in the leg muscles during exercise but is relieved with rest. The disorder is caused by decreased blood flow to the legs due to atherosclerotic narrowing of the arteries in the legs. The manufacturer claims that the drug improves the flow of blood through the blood vessels by making red blood cells more flexible.

The editors of the highly respected Medical Letter on Drugs and Therapeutics, an independent source of drug information for pharmacists and physicians, concluded their 1984 review of the drug by saying:

Pentoxifylline may increase walking distance in some patients with symptoms of intermittent claudication, but it appears to be less effective than physical training. The drug might be worth trying in patients who cannot follow an exercise program and are not good candidates for surgery.[1]

A recent review of the effects of exercise for leg pain due to intermittent claudication found that exercise is of significant benefit to patients with leg pain due to this disorder.[2]

Pentoxifylline also may have serious dangers. There have been two reports of pentoxifylline causing fatal damage to patients’ bone marrow.[3]

Swedish drug regulatory authorities refused to approve pentoxifylline in 1995.

Bleeding has been reported in patients treated with pentoxifylline.[4]

The FDA updated the drug product information for pentoxifylline in 2014 to indicate that patients with liver or kidney impairment may have increased blood levels of the drug because of decreased clearance of the drug.[5] A lower dose may be appropriate in such patients.