PRACTICE CHANGER
Consider prescribing spinosad—a recently approved topical pediculicide that is more effective than permethrin and eliminates the need for nit combing—for children with head lice.1
Stough D, Shellabarger S, Quiring J, et al. Efficacy and safety of spinosad and permethrin crème rinses for pediculosis capitis (head lice). Pediatrics. 2009;124:e389-e395.
STRENGTH OF RECOMMENDATION
B: Based on a single randomized controlled trial (RCT).
ILLUSTRATIVE CASE
A 6-year-old girl is brought in by her mother, who has just been notified of an outbreak of head lice in the child’s school. You examine her scalp and observe viable eggs (nits) at the hair shaft, and tell mom that her daughter has head lice. What’s the most effective treatment?
Head lice are common and easily spread among schoolchildren—and a source of frustration for patients, parents, and family physicians alike. Permethrin cream 1% (Nix), one of the most widely used and well-studied pediculicides, is available over the counter.2
Prescription pediculicides, including malathion (Ovide) and lindane (Kwell), are used less frequently due to their side effect profiles: Malathion is highly flammable due to a high alcohol content and lindane can cause neurotoxicity.2 Both are typically reserved for cases resistant to permethrin 1% cream. Local resistance patterns influence physician prescribing, of course, and greater resistance has increased the need for multiple treatments.3
Dual treatment—and combing— are often required
Permethrin is pediculicidal (ie, it kills only live lice); it is not ovicidal (ie, it does not kill nits at every stage).4,5 Thus, a second application is usually needed 7 to 10 days after the first to ensure complete eradication. And, because permethrin is not ovicidal, nit combing—a tedious, time-consuming, and often painful process—is required to remove lice and unhatched eggs from the hair shafts. Another downside: Children in districts that do not allow students to return to school until they are completely nit-free often miss school as a result of this lengthy process.
The US Food and Drug Administration (FDA) recently approved spinosad (Natroba topical suspension 0.9% cream rinse) for the treatment of lice in patients ≥4 years old.6 Spinosad, which is available only by prescription, eliminates the need for nit combing. But how well does it work?
STUDY SUMMARY: For most patients, a single application is sufficient
The study by Stough et al included 2 identical multicenter RCTs comparing 0.9% spinosad without nit combing vs 1% permethrin with combing in patients ≥6 months old who had active head lice. There were 446 patients in the primary treatment (spinosad) group and 470 in the control (permethrin) group. All participants within the same household were assigned to the same group.
Participants were evaluated on Days 1, 7, and 14. Those with active lice on Day 7 received another treatment (a second application with the same medication). The primary outcome was the percentage of participants who were lice free on Day 14.