Study Finds Drug Kills Most Head Lice

A newer drug appears to work well against head lice, researchers report. The new study used a lotion made with ivermectin, an insecticide. Researchers randomly divided 765 children who were infested with head lice into 2 groups. One group received ivermectin lotion. The other got a placebo containing no medicine. The lotions were applied to the hair and left on for 10 minutes before rinsing. A day later, 95% of the ivermectin group and 31% of the placebo group were louse-free. Researchers also checked at day 15 because louse eggs may hatch after treatment. At that point, 74% of the ivermectin group and 18% of the placebo group still had no lice. Researchers said current treatments, such as permethrin and pyrethrin, are only about 50% effective. Lice also have been gaining resistance to these treatments.