Spinosad in recent scientific literature

Spinosad has been the topic of two recent papers investigating its effectiveness in treating pediculosis in humans.

A review paper in the October 2011 issue of the American Journal of Clinical Dermatology discussed the results of several randomised clinical trials comparing spinosad with permethrin and nit combing. It concluded that topical spinosad 0.9% solution was 'significantly more effective' at eradicating head lice even without nit combing, compared to the combination of a 1% permethrin solution and nit combing. The majority of subjects only required a single spinosad treatment to remove their head lice.

A broader MEDLINE review paper published in the January 2012 issue of Clinical Therapeutics looked at clinical trials comparing spinosad at different concentrations to either placebo or permethrin solutions. They report on three trials in the literature.

A small study (n = 120) showed that both 0.5% and 1.0% solutions of spinosad were effective in over 80% of cases (judged by number of patients lice-free after 14 days). The results for both concentrations were statistically significant at the 1% level versus placebo.

A larger study (n = 1038) summarizes the recent Am. J. Clin. Dermatol. paper, discussed above. Spinosad 0.9% was found to be effective in over 80% of cases, versus approximately 40% effectiveness for permethrin 1% solution. Significance was once again at the 1% level.