Pharmacology Update
Ivermectin Lotion 0.5% (Sklice)
By William T. Elliott, MD, FACP, and James Chan, PharmD, PhD. Dr. Elliott is Chair, Formulary Committee, Northern California Kaiser Permanente; and Assistant Professor of Medicine, University of California, San Francisco. Dr. Chan is Pharmacy Quality and Outcomes Manager, Kaiser Permanente, Oakland, CA. Drs. Elliott and Chan report no financial relationships relevant to this field of study.
A new topical preparation for the treatment of head lice has been approved by the FDA. Ivermectin is a macrocyclic lactone antibiotic that has been used orally both on and off label for head lice since 2001. This new formulation is a topical lotion (oral invermectin is not approved in the United States). It is manufactured by DPT Laboratories and is distributed by Sanofi Pasteur, Inc., as Sklice.
Indications
Ivermectin lotion is indicated for the topical treatment of head lice infestation in patients 6 years of age and older.1
Dosage
Ivermectin is applied as a single 10-minute application to the hair and scalp. It is available as a 0.5% lotion.
Potential Advantages
Ivermectin solution is well tolerated and provides another option for the treatment of head lice.
Potential Disadvantages
Approximately 25% of those treated with topical ivermectin were not lice free. It may be less effective than other products (e.g., spinosad or oral invermetin).
Comments
Ivermectin is believed to cause paralysis and death of mites by selective binding to glutamate-gated chloride channels.1 Its efficacy was shown in two randomized, vehicle controlled studies in subjects with head lice.1 The youngest subject from each household was the primary subject for assessment of efficacy. Other members were evaluated for safety. All infected subjects were randomized to ivermectin or vehicle only as a single application. The primary endpoint was percent free of lice 14 days after application. The results from the two studies were 76.1% (54/71) and 71.4% (50/70) for ivermectin compared to 16.2% (12/74) and 18.9% (14/74) for the vehicle. Ivermectin appears to be well tolerated as adverse reactions (conjunctivitis, ocular hyperemia, eye irritation, dandruff, dry skin, and skin burning sensation) occurred in fewer than 1% of subjects.1 There are no published comparative studies with other topical agents such as permethrin, benzyl alcohol, malathion, spinosad, or oral ivermectin. For rough comparisons, the cure rate (lice free in 2 weeks) of approximately 74% compared to 44%-68% for permethrin, 76% for benzyl alcohol, 85% for spinosad, 85%-98% for malathion, and 95% for oral ivermectin.2-5
Clinical Implications
Head lice is a common infestation in children ages 3-12.6 Permethrin is commonly used but generally requires two applications. Benzyl alcohol and spinosad need one application with success rates at least as good as topical ivermectin.
References
1. Sklice Prescribing Information. Swiftwater, PA: Sanofi Pasteur; February 2012.
2. Stough D, et al. Efficacy and safety of spinosad and permethrin creme rinses for pediculosis capitis (head lice). Pediatrics 2009;124:e389-e395.
3. Heukelbach J, et al. A highly efficacious pediculicide based on dimeticone: Randomized observer blinded comparative trial. BMC Infect Dis 2008;8:115.
4. Benzyl alcohol lotion for head lice. Med Lett Drugs Ther 2009;51:57-58.
5. Chosidow O, et al. Oral ivermectin versus malathion lotion for difficult-to-treat head lice. N Engl J Med 2010; 362:896-905.
6. Frankowski BL, et al. Head lice. Pediatrics 2010;126: 392-403.
A new topical preparation for the treatment of head lice has been approved by the FDA. Ivermectin is a macrocyclic lactone antibiotic that has been used orally both on and off label for head lice since 2001. This new formulation is a topical lotion (oral invermectin is not approved in the United States). It is manufactured by DPT Laboratories and is distributed by Sanofi Pasteur, Inc., as Sklice.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content