Painful nerve damage in diabetics, which is called diabetic peripheral neuropathy, is a most disabling and disturbing conditions that wreaks havoc on quality of life. It affects between a quarter and half of diabetes mellitus patients, leaving most unable to detect pinpricks or other sensations in their feet or legs.

Diabetic neuropathy is linked to more injurious falls and an increase in foot ulcers, which often results in amputation. The condition is believed to be caused by poorly controlled blood sugar levels.

Physicians who treat painful diabetic neuropathy should first rule out other causes of the pain.

They also should counsel patients to get their glucose levels as close as possible to the normal range. Many years ago I showed that when we infused normal males with glucose, they were less able to tolerate pain. Similarly, diabetics with high blood glucose levels feel more pain than those with normal blood sugar levels. Glucose appears to coat the opiate receptor making it impossible for the bodies' own morphine (endorphins) to regulate pain.

Numerous medications relieve neuropathic pain. Tricyclic antidepressants, such as desipramine, are inexpensive, work as well as more expensive antidepressants, and are a mainstay of treatment. Anticonvulsants, such as tegretol, also are as effective in decreasing pain as newer and more expensive anticonvulsant medications.

A recent study suggested that the opiate oxycodone should be used for severe pain. A chili pepper cream (capsaicin) or the local anesthetic lidocaine can be rubbed on the legs to decrease pain.

Two drugs actually may treat the condition instead of simply relieving pain. A number of studies have shown that a 600 milligram daily dose of alpha-lipoic acid, a "super antioxidant" that is available without a prescription, has positive effects as early as two weeks after starting it.

My friend, Dr. Arthur Vinik, has found that the anticonvulsant topiramate can cause nerve fibers to regrow. The medication causes weight loss, and research has shown it decreases pain. I have treated a number of patients by combining alpha-lipoic acid and topiramate with excellent results.

The bottom line is if you have painful diabetic neuropathy, discuss these alternatives with your physician.

SLUCare physician John Morley is director of geriatrics at St. Louis University and a geriatrician at St. Louis VA Medical Center. E-mail him at morley@slu.edu. The Aging Successfully column for seniors rotates each week with XX Files, a women's health column.