April 7, 2011
In March 2011, study results on a medicinal patch used to ease the pain due to HIV neuropathy were released at the annual meeting of the American Academy of Pain Medicine in Maryland. These results have not yet been peer reviewed, but may offer hope for many who struggle with controlling nerve pain in their lower legs and feet.
In this study, 239 people were treated once with an 8% capsaicin patch for 30 minutes while another 99 were treated with a 0.04% capsaicin patch. They were followed for another three months. Capsaicin is the component responsible for the heat found in chili peppers.
People were first treated with 4% lidocaine for 60 minutes before the patches were applied to the feet. This is because the patch itself can initially cause pain and burning. Pain killers were also given to anyone who continued to have manageable pain from the patch, some up to a week afterwards.
After three months from one use of the patch, 27% of those using the 8% patch reported a decrease in their pain, compared to 15.7% on the 0.04% patch. About 36% of those on the 8% patch reported that their pain was either much or very much improved, compared to 22% of those on the other patch.
Nearly all (98%) tolerated at least 90% of the one-time, 30-minute application. Most common side effects were, understandably, redness and pain at the site of the patch, which went away within a week.
These results offer hope for some people to reduce the nerve pain they feel in their feet and lower legs, although it’s not clear if this benefit continues beyond three months. More than half of people living with HIV will experience neuropathy at some point. And of those nearly one-third will have painful nerve problems. Few options are available to help ease this type of pain, so new alternatives are needed.
RESEARCH:
Vanhove G, et al “Efficacy of NGX-4010 (Qutenza), a capsaicin 8% patch, applied for 30 minutes in patients with HIV-associated neuropathy: Results of integrated analyses” AAPM 2011; Abstract 139.