title: Topical ivermectin 0.5% lotion for treatment of head lice.
abstract: OBJECTIVE
  To investigate the pharmacology, pharmacokinetics, efficacy, adverse effects, and place in therapy of a single application of topical ivermectin 0.5% lotion for head lice treatment.
  
  
  METHODS
  Literature was obtained by searching MEDLINE, PubMed, CINAHL, and Scopus (January 1980 to January 2013). Abstracts were searched for the terms ivermectin AND (head lice or pediculus or pediculosis), topical ivermectin, ivermectin lotion, ivermectin AND (pharmacology OR pharmacokinetics). The New Drug Application filed with the Food and Drug Administration and the product data sheets for ivermectin were obtained.
  
  
  METHODS
  All English-language articles retrieved from the search were evaluated for relevance to the objective.
  
  
  RESULTS
  The recommended first-line head lice treatments in the United States are permethrin 1% or pyrethrins, with malathion 0.5% lotion used as a second-line treatment. Significantly more of the 289 head lice-infested participants using topical ivermectin 0.5% lotion were lice-free at day 15 when compared with vehicle control (73.8% vs 17.6%; P < .001) in 2 studies. Although this rate is lower than other third-line treatments (eg, spinosad 0.9% or benzyl alcohol 5%), topical ivermectin 0.5% lotion is well tolerated (pruritus, the most common adverse event, 0.9%) and requires only a single application.
  
  
  CONCLUSIONS
  Topical ivermectin 0.5% lotion kills head lice by increasing chloride in muscle cells, causing hyperpolarization and paralysis. Only 1 application is required; when the treated eggs hatch, the lice are not viable because they cannot feed as a result of pharyngeal muscle paralysis. Minimal systemic absorption occurs following topical application. Studies have demonstrated that topical ivermectin 0.5% is a safe and efficacious treatment for head lice. Although it has no documented resistance, there is limited clinical experience, it requires a prescription, and it is expensive. Therefore it should be reserved as a third-line treatment for head lice in the United States.
authors.affiliation: University of Canberra, Canberra, Australia.
authors.forename: Louise S
authors.initials: LS
authors.lastname: Deeks
authors.forename: Mark
authors.initials: M
authors.lastname: Naunton
authors.forename: Marian J
authors.initials: MJ
authors.lastname: Currie
authors.forename: Francis J
authors.initials: FJ
authors.lastname: Bowden
mesh_terms: D000287:Administration, Topical; D000818:Animals; D006801:Humans; D007306:Insecticides / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D007559:Ivermectin / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D010373:Lice Infestations / Q000188:drug therapy*; D063465:Skin Cream
chemical_list: D007306:Insecticides; D007559:Ivermectin
keywords: head lice; ivermectin; lotion; topical