Q. I have pain and numbness in my legs and feet due to nerve damage from diabetes. I can't sleep, my daily and social activities are shot, and I'm depressed. What can I do?

A. Hot off the presses: Man-chun Wong, Joanne W Y Chung and Thomas K S Wong published an article, "Effects of Treatments for Symptoms of Painful Diabetic Neuropathy: Systematic Review," in the July 14 issue of the British Medical Journal. They looked for all studies ever done on this topic, and analyzed only the more accurate randomized ones.

The best by far at reducing pain were tricyclic antidepressant drugs: They work even in folks who are not depressed. They shouldn't be used in those with heart disease, and electrocardiograms should be done before and during therapy. Start at a low dose one or two hours before bedtime, and for Elavil, gradually increase the dose to between 20 and 100 milligrams a day. I like desipramine, as it causes less sleepiness and dry mouth than Elavil but often requires doses of 100 to 150 mg a day.

Next most effective were older epilepsy drugs like lamotrigine, sodium valproate and carbamazepine. They also had the least side effects.

Third most effective were newer epilepsy drugs like gabapentin (Neurontin), Trileptal and Lyrica, though they interestingly had more side effects than the tricyclics or the older epilepsy drugs. For instance, Lyrica can cause dizziness, sleepiness and weight gain.

The fourth most effective was the antidepressant Cymbalta, but it can cause nausea and sometimes liver damage. Narcotics like oxycodone are possibilities if all the above fail, but can cause addiction, constipation, sleepiness and nausea. And the number of folks who stopped the pain pill Ultram (tramadol) due to side effects was higher than the number who had good pain relief from it.

Zostrix or capsaicin cream should be tried first or second because it is safe. It has a powerful natural pain reliever derived from red-hot chili. Use the higher-potency 0.075 percent cream and apply four times a day, but be patient — pain relief is gradual, taking four to six weeks for full relief.

But you need to get at the root cause of the pain, which is too-high blood sugars. Your A1C, which reflects average blood sugar the past three months, should be less than 7 to reduce or prevent painful nerve damage, and you may have to lose weight or get extra exercise, like walking or arm bicycling (search for "pedlar" online) an extra 10 minutes twice a day to get your body to respond to diabetes pills or insulin.

Dr. Landis Lum is a family-practice physician for Kaiser Permanente and an associate clinical professor at the University of Hawai'i's John A. Burns School of Medicine. Send your questions to: Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; islandlife@honoluluadvertiser.com; or fax 535-8170. This column is not intended to provide medical advice.