March 8, 2012 — Permethrin may be slightly more effective than ivermectin in the treatment of scabies. In a study involving 272 patients, a single dose of ivermectin provided a cure rate of 85.9% at 2 weeks compared with a 92.5% cure rate at 2 weeks from 2 applications (at a 1-week interval) of permethrin. The difference was not statistically significant (P = .42) in this noninferiority trial.
Mohamad Goldust, MD, from Tabriz University of Medical Sciences, Iran, and colleagues report the results of their study comparing the efficacy of oral ivermectin with topical application of permethrin in the treatment of scabies in an article published online March 5 in the Journal of Dermatology. The authors found not only a slightly higher cure rate with permethrin but also that permethrin-treated patients recovered earlier.
The cure rate from ivermectin increased to 100% after patients were treated with permethrin after a 4-week interval, according to the authors. Treatment with ivermectin after permethrin increased the cure rate to only 94.2%.
The authors suggest that a single dose of ivermectin may not be effective because it fails to act against the organism at all stages of its life cycle. Although permethrin attacks both the adult organism and its eggs, ivermectin attacks only the adult organism.
