I first heard about the drug, ivermectin, as a paste wormer for horses. It kills parasites. I then discovered that oral ivermectin has been used for some time, as a last resort when over the counter and prescription head lice shampoos have not been effective. A new study suggests that ivermectin lotion may be the answer parents have been searching for when it comes to controlling head lice.
Researchers said that a single 10-minute hair application eliminated head lice in nearly 3 out of 4 children. The lotion is sold under the brand name Sklice by Sanofi Pasteur, which paid for the study.
Using a lotion with 0.5 percent ivermectin, the researchers found that after 14 days it had worked in 73.8 percent of 141 volunteers - most of whom were children younger than 12. In comparison, 17.6 percent of the 148 kids (and a handful of adults) whose hair was treated with a drug-free form of the lotion were louse-free after two weeks.
Lotions were applied to dry hair and then rinsed out after 10 minutes. The immediate success rate, judged the day after the lotion application, was 94.9 percent in the test group and 31.5 percent in the control group.
"The advantage of it is, it's a one-application, one-shot treatment," lead author Dr. David Pariser of Eastern Virginia Medical School, in Norfolk, told Reuters Health.
The study involved children from 11 states and did not compare the ivermectin to any other treatment. But in a previous study where ivermectin was tested against other drugs, Pariser and his colleagues note that ivermectin showed a similar one-day success rate of 92.4 percent while malathion, an insecticide sometimes used to treat lice, cleared 82.4 percent of patients after one day.
The FDA approved Sklice, in February 2012, for topical treatment of head lice in patients 6 months or older. The lotion is only available by prescription. On the website, sklice.com, common side effects are listed as eye redness or soreness, eye irritation, dandruff, dry skin and a burning sensation of the skin.
Some physicians have said they expect the ivermectin lotion to have less systemic adverse effects than the oral medication. However, they believe that it should be used as a last resort when more established treatments fail.
Head lice have 3 stages of life: the egg (also called the nit), the nymph and the adult. Any treatment will need to be able to eradicate all three stages.
Some physicians have also stated they believe that more than one application of the ivermectin lotion may be necessary if the first application doesn’t completely kill all the live lice, newly laid nits and the nymphs.
Dr. Sue Hubbard, pediatrician and co-founder of The Kid’s Doctor, says she understands how frustrating head lice can be for parents as well as children.
In a recent article on the subject she notes: “The first line treatment for lice is NOT to shave your child’s head (as one mother threatened), but to buy one of the over-the-counter products for the treatment of head lice. These products contain either permethrin or pyrethrin.”
She also writes that “It is important that a parent follow the directions: using a hair conditioner before the use of the OTC product can diminish the effectiveness, and many products recommend not washing the hair for several days after finishing the application. It is also important to follow the directions for re-applying the product in order to treat hatching lice and lice not killed by the first application. In other words, you must read the package insert!”
If you have tried over-the-counter head lice remedies and still have not been able to get rid of the little buggers, talk to your pediatrician or family doctor about a prescription treatment plan.
Besides Sklice, other medications that require a prescription to treat head lice are Natroba, Ovide and Ulesfia.