November 14, 2012
Getting Ahead of Persistent Lice Infestation

Swiftwater, PA—Here’s another option for the harried and slightly embarrassed parents who approach pharmacists with an urgent concern: Nothing seems to be getting rid of their child’s head lice.

Just one 10-minute application of topical ivermectin without nit combing was found to be effective and safe for killing head lice, according to industry-sponsored studies. Topical ivermectin is marketed as Sklice by Sanofi-Pasteur and has been available in the U.S. since August.

Unlike some other lice products, however, Sklice requires a prescription. It also is not recommended as a first-line treatment.

The report, published recently in The New England Journal of Medicine, said that  compared to an inactive vehicle control, ivermectin lotion resulted in a higher percentage of patients who were louse-free 1 day after treatment (94.9% versus 31.3%), 1 week later (85.2% versus 20.8%), and 2 weeks later (73.8% versus 17.6%). In the studies of 765 patients, ivermectin resulted in no increase in serious adverse reactions compared to the inactive ingredient.

“The results of the two studies reported here indicate that ivermectin is a treatment option when permethrin or pyrethrins have failed or when there is a desire to reduce the need for nit combing and increase the probability of success with a single application,” study authors write.

An accompanying editorial from French researchers notes that “a topical drug formulation is indeed welcome and is expected to have less risk of systemic adverse events,” but raises concerns that overuse of the product could lead to the emergence of resistant parasites, especially in areas of the world where ivermectin is used to treat onchocerciasis.

The commentators recommend that health care providers continue to follow “the 2010 American Academy of Pediatrics recommendations to use 1% permethrin or pyrethrin insecticide as first-line therapy.” While also recommending other options such as wet combing or treatment with dimethicone, they suggest that if community resistance exists or lice are present 1 day after the completion of treatment, malathion may be necessary,

“Ivermectin should be the last choice,” they write.

In the U.S. each year, head lice cases affect an estimated 6 to 12 million children aged 3 to 11 years old.

U.S. Pharmacist Social Connect