London: Millions suffer peripheral pain and other troubling sensations from diseases as varied as diabetes, AIDS, shingles and arthritis. Now a new review suggests that four out of 10 people could experience some pain relief from cream of topical capsaicin, an active component of chili peppers.
Oxford University researchers Sheena Derry and Andrew Moore led the review, which comprised nine studies involving 1,600 adult participants.
The reviewers said it might be best to consider capsaicin cream as an extra pain-relief measure or a later, if not last, resort when treatment is inadequate, especially since there have been studies on oral medicines for nerve pain that provide clear evidence of their effectiveness and side-effects.
One drawback with capsaicin is that commonly patients experience local skin irritation - burning, stinging or redness - at the application site.
These side-effects generally prove mild and transient but do lead some patients to discontinue capsaicin.
Capsaicin preparations available in the US include Zostrix, Capzasin-P and RT Capsin.
Researchers were following up on a related 2004 review about capsaicin treatment for neuropathic pain, which implied that capsaicin might serve as a useful addition to or as a single therapy for certain patients who did not respond well to, or could not tolerate, other treatments.
Scott Zashin, clinical associate professor of medicine at the University of Texas Southwestern Medical School (UTSMS), said generally he does not use capsaicin in his own practice.
Since 2004, new developments in capsaicin formulations, notably the development of a high-dose (eight percent) patch, added timeliness to the new research review, said an UTSMS release.
The new review appears in the latest issue of The Cochrane Library.