Nerve Pain and Numbness

Peripheral neuropathy can cause numbness, tingling, burning and sometimes severe pain. It most often occurs in the toes, feet and lower legs, but can also arise in the hands and arms. Normally, both sides of the body are affected. It is important to identify the cause so it can be addressed, and your doctor may want to order some tests.

If your nerve symptoms appear to be caused by a medication, it should be stopped as soon as possible. Delay could result in permanent problems. When medications causing the problem are stopped shortly after symptoms begin, pain and numbness usually subside over time. Too many people have ended up with permanent pain, numbness and burning because the symptoms of peripheral neuropathy weren’t identified soon enough or they continued too long on the medication after the pain started.

The antiretroviral drugs that were once the most frequent cause of neuropathy in people with HIV — d4T (Zerit), ddC (Hivid), and ddI (Videx EC) — are no longer in common use in Canada. Much less commonly, neuropathy can be caused by 3TC (lamivudine, and in Combivir, Kivexa and Trizivir) and T-20 (enfuvirtide, Fuzeon). Many other drugs can also cause this condition, so if you begin to develop symptoms of peripheral neuropathy, it is important to discuss with your doctor and pharmacist the possibility that a medication is contributing to the problem.

There are other factors that can cause or contribute to peripheral neuropathy as well. These include diabetes, hypothyroidism, alcohol, cocaine or amphetamine use, vitamin B₁₂ deficiency and HIV itself.

Anecdotal reports and clinical trials in people with diabetes and people with HIV have shown the following nutrient supplements to be useful in preventing or reversing peripheral neuropathy:

• alpha-lipoic acid (in doses of 300 mg, one to two times per day; preferably using an extended-release form)
• gamma-linolenic acid (in doses of 240 mg, twice daily)
• acetyl-L-carnitine (in doses of 500 mg, three times daily with meals).

Antiretroviral drugs, particularly the older nucleoside analogues (nukes) listed above, can damage mitochondria, the power plants of cells. This is thought to contribute to neuropathy and other health problems. Fortunately, the newer nukes appear not to cause the extent of mitochondrial damage seen with the older drugs.

Because of the link between mitochondrial damage and neuropathy, some people seek to prevent or reverse mitochondrial damage by taking a combination of antioxidants, B vitamins and the amino acid acetyl-L-carnitine. One way to get this combination of nutrients is to take:

• a potent multivitamin that includes the whole B vitamin complex and a broad spectrum of antioxidants (vitamin C, carotenoids, selenium and others)
• a supplement of acetyl-L-carnitine (500 mg, three times daily with meals).

When B complex vitamins have been determined to be too low, some people have reported it helpful to supplement, especially with vitamin B₆ (25 to 50 mg daily taken as part of a B complex supplement) and vitamin B₁₂ (see the appendix for more info about this vitamin). Taking very large amounts of vitamin B₆ has been linked to nerve problems. The recommended maximum daily dose is 100 mg. Vitamin B₁₂ is generally safe, even at high doses.

Some people also take magnesium, a mineral essential for nerve function. The recommended maximum daily dose for magnesium is 350 mg daily, though doses of 500 to 600 mg per day may be needed by some people to see benefit. Doses above 350 mg of magnesium daily can cause diarrhea. Magnesium glycinate may be better tolerated than other forms.

Vitamin D may also be helpful. Multiple studies have shown that vitamin D deficiency is common in people with HIV. A study in people with diabetes showed that the pain of peripheral neuropathy was cut almost in half after three months of supplementation with vitamin D. See the appendix on vitamin D for more information.

Anything that soothes and reduces pressure on hypersensitive feet or hands can help to reduce pain caused by peripheral neuropathy. This includes:

• limiting the amount of walking
• avoiding wearing tight-fitting shoes and socks
• avoiding standing for lengthy periods
• avoiding repetitive pressure on the hands
• soaking your feet or hands in ice water regularly
• raising your heels or hands off the mattress with a small pillow to help prevent increased pain while sleeping
• keeping heavy covers off painful areas
• exercising regularly
• getting acupuncture or acupressure.

If you are experiencing numbness or lack of sensation in your feet, it’s a good idea to get in the habit of checking your feet every day when you remove your shoes and socks. Sometimes neuropathy prevents you from feeling cracks and sores on your feet. A visual inspection can help you identify any problems early to prevent them from getting worse.

Although they have mostly been studied for diabetic neuropathy, the following medications and treatments can help some people with HIV reduce the pain of peripheral neuropathy, although they won’t eliminate numbness:

• Antidepressants such as amitriptyline (Elavil) and nortriptyline (Aventyl) may be useful. Side effects can include drowsiness, dry mouth, constipation, lack of urination and low blood pressure upon suddenly sitting up or standing. Nortriptyline tends to cause less drowsiness than amitriptyline and can be useful for daytime pain management, while amitriptyline can be helpful for pain that is worse at night. Duloxetine (Cymbalta) is a newer antidepressant used for nerve pain; it can cause nausea and sleep disturbances initially as well.
• Antiseizure medications such as gabapentin (Neurontin) and pregabalin (Lyrica) can also be useful for nerve pain. These medications can cause drowsiness, dizziness and weight gain in some people. Other antiseizure medications, such as carbamazepine (Tegretol) and phenytoin (Dilantin), are often used to treat nerve pain, but these have significant interactions with antiretroviral drugs, including non-nukes and protease inhibitors, and should not be taken if you are using these medications.
  
  All of these medications are usually started at a low dose and increased gradually to minimize side effects, especially sedation and dizziness. It is important to note that pain relief is not immediate with these medications; it can take as long as six to eight weeks before the full benefit of antidepressant or antiseizure medications is felt, so try to be patient and don’t give up too soon.
• Anti-inflammatory drugs such as ibuprofen (Advil, Motrin) may help with mild neuropathic symptoms. Opioid pain killers can be used to help manage more severe pain that doesn’t respond to other medications.
• Capsaicin, derived from chili peppers, applied as a cream or patch directly over the painful areas, has been shown to help reduce neuropathic pain. Capsaicin cream will only result in a temporary reduction in pain so it must be used regularly to provide prolonged pain relief. Some people feel significant burning sensations on the skin when the cream is applied, so not everyone can tolerate it.
• Marijuana and its synthetic version, nabilone (Cesamet), are sometimes helpful for treating pain related to neuropathy. For a full discussion of approaches to using these drugs, see the section Nausea, Vomiting and Appetite Loss.
• Geranium oil has been reported by some people to help when rubbed onto the skin of the painful area.