An estimated 60-70 percent of people with diabetes have some form of neuropathy, making it one of the most common complications of diabetes. The symptoms of diabetic peripheral neuropathy (DPN)—nerve damage in the extremities—are most often felt in the toes, feet, and hands.
Common descriptions of the feelings or sensations for DPN are:
• Electrical vibrations
• Shooting pain
• Searing pain
People experience the nerve damage from DPN in different ways. For example, a person can lose feeling without pain or have pain without numbness or have no pain at all. The most common symptoms are burning and numbness, which can be key for diagnosis.
"It's usually a loss of feeling, and then a burning sensation where that feeling's been lost," says Robert Gerwin, M.D., pain management specialist and associate professor of neurology at Johns Hopkins University School of Medicine in Baltimore. "It's not the dull, sore muscle and joint aches and pains that you may feel from aging," he says. And when these symptoms aren't given the attention they deserve, they're likely to progress.
Read on to learn why pain occurs, along with descriptions of commonly prescribed medications; topical analgesics, such as capsaicin and lidocaine; and treatments for pain that complement other therapies, such as acupuncture and transcutaneous electrical nerve stimulation (TENS).
Talk with your doctor about the following options, and decide together what methods of pain relief will help you live more comfortably.
"People with diabetic neuropathy should not be in chronic pain," says pain management specialist Robert Gerwin, M.D. Good control of blood glucose levels is an important step to both prevent nerve damage and control it. If you don't figure out how to control your pain with your doctor in its early stages, it may become more unbearable.
A process called central sensitization occurs when the nerves throughout your body -- commonly starting at your toes and feet -- begin to transmit pain. When they continue to do so for a prolonged period of time, that pain moves at a higher frequency and the sensation feels stronger. This causes the nerve cells to become permanently damaged and eventually die, leading to genetic changes in the cells. Your nervous system may lose the ability to control the sense of pain, says Ed Ross, M.D., director of the Pain Management Center at Brigham and Women's Hospital in Boston.
The portion of the nerve that is most affected is farthest from the nerve cell in your spinal cord, where nutrition and chemical elements that are important to the nerves originate, Gerwin says. So the leg's long nerves and nerve endings in the toes are affected first. He says that if neuropathy goes untreated long enough, pain can progress to the fingers and other parts of the body.
"Diabetic neuropathy is an ongoing chronic problem," says Robert Gerwin, M.D. "But I think we, as pain specialists, are seeing fewer cases than we did before because it's being handled more by the primary physicians, which is a good thing." He says this is primarily because the pain medications are now commonly used by endocrinologists and internists, not just pain specialists.
Medications can be your first resort or your last. "In general, the recommendation is to increase medications stepwise, starting with the mildest drug that is effective," Gerwin says. "When someone has very mild pain, anti-inflammatory drugs like ibuprofen and acetaminophen work fine."
Problems with this method arise when a person is experiencing severe pain—then, Gerwin says, it makes no sense to start with a low-level pain medication. By the time a visit to the pain clinic is necessary, patients usually have been through the mill with what their primary care physician has prescribed and the pain is out of control.
The following slides discuss the three main medications that are generally prescribed to treat diabetic peripheral neuropathy.
Nerve-calming medications pregabalin (Lyrica) and gabapentin (Neurontin) were designed to help people who have epilepsy. But the nerve-calming qualities of many of these drugs can also help quiet the burning, stabbing, or shooting pain often caused by nerve damage. These medications can decrease nerve transmissions, slowing their electrical and painful impulses. Gabapentin is prescribed as a common first step in terms of prescription medications to treat neuropathy.
"If you're treating someone who has depression along with their diabetes, you'd start them with an antidepressant," says Robert Gerwin, M.D. These medications are sometimes known as seratonin and norepinephrine reuptake inhibitors, or SNRIs. SNRIs boost seratonin in the brain, which will help decrease pain transmission. Two SNRIs available after approval by the U.S. Food and Drug Administration are duloxetine (Cymbalta) and milnacipran (Savella).
Tricyclic antidpressants, such as imipramine (Tofranil), nortriptyline (Pamelor), and amitriptyline (Elavil), are still being used though many patients cannot tolerate higher doses due to side effects, says Marty Irons, R.Ph., CDE, a Diabetic Living advisory board member.
Both anticonvulsants and antidepressants may increase blood glucose, so make sure to monitor your levels carefully and tell your health care provider about any significant changes.
Some primary care physicians skip antidepressants and anticonvulsants as options for pain relief and prescribe opioids such as hydrocodone with acetaminophen (Vicodin) and oxycodone with acetaminophen (Percocet), says Ed Ross, M.D.
Opioids may not be the best front-line or single-treatment option for people who have neuropathy pain, because such medications don't have much effect on chronic pain within the nervous system. Addiction can also be an issue with this type of medication.
Before starting medications, or if the medications prescribed to you aren't enough, over-the-counter and prescription off-label (non-FDA-approved) topical analgesics in cream, gel, and oral forms may ease the tingling, numbness, or dull pain you feel in your extremities. The following slides discuss the three common types of topical treatments available to ease the pain of diabetic peripheral neuropathy.
Ed Ross, M.D., a pain management specialist, says there is some evidence to support that capsaicin (DiabetAid Pain and Tingling Relief; Zostrix), which is extracted from chile peppers, relieves nerve pain. "However, many of the patients I see can't tolerate it," he says. This over-the-counter topical agent, which is available in creams and other forms, irritates the nerves and keeps them firing until then they fatigue, allowing the pain to reduce.
"Capsaicin works, but it is very hard for people with a burning pain from neuropathy because it really stings and burns. It just magnifies the pain," says Robert Gerwin, M.D. The burning will settle after your body builds a tolerance, because it works by eliminating one of the chemicals that initiates pain, but it takes about a week to 10 days, with three to five applications per day. If you stop using it, even for a day, the benefit is gone and the burning sensation returns.
Unlike capsaicin, lidocaine (Lidoderm)—an anesthetic commonly applied to the skin through a pliable patch but also available in gel form—should not irritate your skin. In fact, if you feel any sort of burning or pain, you should remove it immediately. You can apply up to three patches every 12 hours to relieve pain in the most affected areas of your body.
If you use this product, remember to wash your hands after placing it on your skin, unless you're applying it to relieve hand pain. If used for hand pain, rinse it off after 30 minutes. When disposing of the patch, fold it over onto itself and put it in a waste container that is not accessible to children or pets.
Custom pain gels that combine medications such as ketoprofen, gabapentin, ketamine, and lidocaine can be prescribed by your physician and made by a compounding pharmacist. Topical delivery of these medications allows for more direct treatment to the affected area without the side effects of oral medications because very little gets into the blood.
Though topical treatments as a stand-alone pain therapy are poorly evaluated, Ed Ross, M.D., recommends using them in combination with other pain-treatment therapies, both medications and complementary options, to help diminish mild pain.
Pain relief doesn't always come in the form of medication. There are several complementary options to relieve the early phases of neuropathic pain. Acupuncture and transcutaneous (through the skin) electrical nerve stimulation (TENS) are two that seem to have stronger medical support than others such as massage, relaxation therapy, and meditation.
Acupuncture can help relieve discomfort throughout the body by painlessly inserting thin needles, usually made of stainless steel, into different points along the body's energy flow, or qi (pronounced "chi"). Practitioners believe obstructions in this pathway are the source of pain you feel and are usually caused by an illness like diabetic neuropathy. The needles clear the energy flow and relieve pain. Acupuncture has been shown to lower stress hormones, leading to less inflammation throughout the body.
TENS is a noninvasive approach to treating neuropathic pain. Electrode patches are attached to your skin from a TENS unit, which is a portable device that you can wear around your waist. The patches send an electrical current that will fatigue the nerves, which makees them too tired to process pain. TENS is commonly prescribed for very mild pain.
It's easier—and less expensive—to prevent pain than to treat it. In addition to steady blood glucose control, Ed Ross, M.D., suggests three ways to prevent the onset of neuropathic pain.
Exercise. Regular physical activity can help you lose weight, which can slow the progression of pain by reducing inflammation throughout the body. But if you already feel minor symptoms of neuropathy, don't stop moving. Find low-intensity workouts such as swimming or cycling to get in your minutes of activity throughout the day. Talk with your health care provider about pain-free exercises that will suit you and your schedule.
See your health-care provider regularly. The American Diabetes Association recommends that all patients should be screened for DPN starting at diagnosis of type 2 diabetes, and five years after the diagnosis of type 1 diabetes, and at least annually thereafter, using simple clinical tests, such as a 10-gauge monofilament to test nerve sensation in the feet.
Treat pain aggressively. Be honest with your doctor about what you're feeling. "If you have any feeling of pain—or a tingling or numbness sensation that might lead to pain—and it's not well controlled, the prognosis for further pain is much higher," Ross says.
It's difficult to remember all the things you're concerned about during your 10 or so minutes with a doctor. But once you lie down in bed and put your feet under the covers, it's hard to forget the tingling pain in your toes. Print this Where It Hurts Worksheet to write down when and where you feel any sort of numbness, pain, tingling, or burning. Bring the sheet to your next checkup to discuss with your health care provider.