LOS ANGELES — Head lice are itchy, nasty nuisances that can be hard to get rid of. Can a pill provide relief? A new study has found that in tough cases, an oral medication kills the parasites more effectively than a prescription lotion applied to the scalp.
The study, published today in the New England Journal of Medicine, compared ivermectin — an antiparasitic drug used for human cases of river blindness and for animal parasites — with a lotion containing the insecticide malathion.
Ivermectin is not approved for use in the U.S. for head lice. Malathion, a topical insecticide available by prescription, is usually used as a second-phase head-lice treatment after over-the-counter topical products have failed.
The study of 812 people in 376 households found that in the ivermectin group, 95.2 percent of the participants were lice-free after two weeks, compared with 85 percent of the malathion group. Of households, 171 of 185 using ivermectin were head-lice-free, compared with 151 of 191 using malathion.
Timothy Gibb, an extension entomologist with Purdue University in West Lafayette, Ind., said the finding is important because of the resistance developing among head lice to other insecticides.
“This gives us another tool in the arsenal,” he said. “It makes it much more difficult for the head lice to develop a resistance to all of these things at once.”
