The AIDS Beacon™

Although research is still inconclusive, some scientists have found that acetyl-L-carnitine (ALCAR), a natural antioxidant, has the potential to alleviate some of the effects of antiretroviral toxic neuropathy (ATN).

ATN is a painful neurological condition that can be caused by antiretroviral drugs that damage nerve cells, causing pain, tingling, and numbness. It is the most common form of a condition known as HIV-associated sensory neuropathy (HIV-SN).

HIV-SN is estimated to affect one third of individuals with HIV. It is a significant factor in nonadherence to, and discontinuation of, antiretroviral medications.

Development of ATN can occur as a side effect of treatment with one or more nucleoside reverse transcriptase inhibitors (NRTIs), a type of medication often included in antiretroviral therapy.

NRTIs particularly associated with ATN are didanosine (Videx), stavudine (Zerit), and zalcitabine (Hivid).

Currently there are no medications that can effectively eliminate or reverse ATN. Treatment focuses on management of symptoms, especially pain.

Researchers hope that ALCAR will be able to ease pain and possibly prevent or reduce ATN. This hope is based on the compound’s ability to cross the blood-brain barrier and enter the brain’s blood circulation. There it can act as an antioxidant, preventing damage to brain cells.

ALCAR occurs naturally in both plants and animals, and can be taken as a supplement.

Several studies have suggested that ALCAR is not only effective at reducing pain, but also is capable of regenerating nerves to reverse the damage caused by NRTI treatment. Additional studies have noted improvements in pain, but failed to show nerve regrowth.

All of the studies noted that ALCAR use was generally safe and well-tolerated.

• In 2004, scientists at the Blond McIndoe Centre at the Royal Free and University College Medical School in London published the results of ALCAR administration to 21 HIV-positive ATN patients. They found that twice-daily administration of 1500 mg ALCAR for 6 to 12 months reduced ATN symptoms and increased nerve regeneration. No changes in CD4 cell count or HIV viral load were observed. Their positive results were published in the journal AIDS, and prompted further research.

• A 2005 report issued by researchers at the Royal Free Hospital, London, sought to establish whether this symptomatic improvement was long-term. Through follow-up assessment of 16 participants with different adherences to ALCAR treatment, they determined that the improvement was in fact long-term. They also found that patients did not need to discontinue their use of NRTIs to experience this improvement, and outlined their findings in the journal HIV Clinical Trials (pdf).

• Research from the University of Milan and the Department of Infectious Diseases of Milan released the results of a four-week study with ALCAR treatment in the Journal of the Peripheral Nervous System (abstract) in 2006. Through administration of 2000 mg of ALCAR per day to 20 HIV/ATN patients, they corroborated previous findings that the supplement reduced pain symptoms. However, they noted no nerve regeneration.

• A 2007 publication in HIV Medicine by researchers from both the London and Milan groups examined the effects of injected and oral doses of ALCAR to assess the overall safety of ALCAR in either application. The intramuscular injections were administered twice daily in 500 mg doses, and the oral supplements 1000 mg once daily. Both resulted in decreased pain versus the placebo group, and both were reported to be safe. Because the study only took place over an eight-week time period, no inferences on nerve regrowth were drawn.

• The most recent report, released in 2009 in HIV Medicine (abstract) by the Hawaii AIDS Clinical Research Program, found that patients treated with 3000 mg ALCAR daily experienced significant improvement in their pain symptoms over 24 weeks. It was again noted that this improvement did not coincide with any nerve regeneration.

Investigation of ALCAR’s ability to reduce pain and induce nerve regrowth in people suffering from ATN continues.

Additionally, a phase 2 clinical trial is currently underway to see if ALCAR can prevent nerve damage in people taking antiretroviral drugs.

As with any supplement, patients should discuss ALCAR with their physician before adding it to their drug regimen.

For more information on ATN and HIV-SN, please see the Medscape website.