Efficacy of a reduced application time of Ovide lotion (0.5% malathion) compared to Nix creme rinse (1% permethrin) for the treatment of head lice

Publication Type:Journal Article
Year of Publication:2004
Authors:T. Lynn Meinking, Vicaria, M., Eyerdam, D. H., Villar, M. E., Reyna, S., Suarez, G.
Journal:Pediatric dermatology
Pagination:670 - 674
Date Published:2004
ISBN Number:0736-8046
Keywords:adolescent, adult, Aged, animals, child, Comparative Study, Dose-Response, Florida, humans, insecticide, Lice Infestations/drug therapy, malathion, Middle Aged, Pediculus, Permethrin, Research Support, Non-U.S. Gov't, scalp dermatoses, Single-Blind Method, Treatment Outcome

Our objective was to conduct a randomized, investigator-blinded evaluation of the pediculicidal and ovicidal activity of a reduced application time (20 minutes) of Ovide (0.5% malathion) compared to Nix (1% permethrin) in a south Florida population infested with Pediculus humanus capitis. Either Ovide or Nix was applied according to the label instructions. However, Ovide application time was reduced to 20 minutes. At day 8, subjects with live lice were re-treated with the same product and procedure as on day 1. Ovicidal and pediculicidal efficacy were evaluated at days 8 and 15. A subject free of lice and viable eggs at day 15 was considered to be a treatment success. Percent efficacy was calculated using the number of subjects free of lice and viable eggs per total number of subjects treated. We found that a 20-minute application of Ovide was significantly more pediculicidal and ovicidal (98%) compared to Nix (55%) at day 15 (p < 0.0001). The percentage of Ovide subjects who required treatment at day 8 was half that of the Nix group. The reinfestation rate was 0% with Ovide and 33% with Nix. In conclusion, a 20-minute treatment with Ovide, instead of the approved 8- to 12-hour application, cured 40 of 41 subjects (98%), demonstrating superior efficacy to Nix. The poor efficacy of Nix confirms the resistance of head lice to permethrin in south Florida.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith