CapsaicinPain-NeuropathicProf. Ernst

Capsaicin reported safe in a long-term study

Last year, Prof. Ernst reviewed CAM for neuropathic and neurologic pain and reported that topically applied capsaicin was more effective than placebo.

Now, study results presented during the American Academy of Pain Medicine meeting support its safety during long-term use for post-herpetic neuralgia and HIV-related neuropathy.

First, the details.

  • 106-patients with HIV neuropathy or post-herpetic neuralgia were studied for 48 weeks.
  • An 8% capsaicin patch was applied for 60 to 90 minutes, following application of lidocaine cream or other topical anesthetic.
    • Currently available capsaicin patches and creams sold over-the-counter have much lower concentrations of capsaicin — 0.025% to 0.075%.
  • Reapplication after the first treatment was left to the discretion of treating physicians and patients, but the interval between applications was at least 12 weeks.

And, the results.

  • Nearly all patients had a treatment-related adverse effect.
  • All but a handful, however, involved mild to moderate redness (86%) or pain (70%) at the patch site.
  • Only 1 patient stopped treatment because of side effects — burning pain at the patch site.
  • About 15% of patients showed decreases in deep tendon reflexes.
    • Diminished sensations of vibration, heat, and pinpricks were less common.
  • Increased sensitivity to these stimuli was reported in some patients.

The bottom line?
Topical application of capsaicin at these higher doses is not without side effects. However, for post-herpetic neuralgia and HIV-related neuropathy, it’s apparently worth the risk.

A company called NeurogesX is developing a high-dose capsaicin patch therapy. It has been submitted to the FDA for review in anticipation of making it a prescription drug.

It’s another CAM progressing through the system to take it’s place in mainstream medicine.

2/11/09 22:47 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.