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Efficacy of chemical and botanical over‐the‐counter pediculicides available in Brazil, and off‐label treatments, against head lice ex vivo
Author(s) -
Asenov André,
Oliveira Fabíola Araújo,
Speare Rick,
Liesenfeld Oliver,
Hengge Ulrich R.,
Heukelbach Jorg
Publication year - 2010
Publication title -
international journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 93
eISSN - 1365-4632
pISSN - 0011-9059
DOI - 10.1111/j.1365-4632.2009.04335.x
Subject(s) - ex vivo , medicine , in vivo , head (geology) , traditional medicine , pharmacology , microbiology and biotechnology , biology , paleontology
Background There is a lack of reliable data on the efficacy of over‐the‐counter (OTC) pediculicides in Brazil. Methods We performed ex vivo assays of eight marketed pediculicides: 1% permethrin (Kwell®, Clean Hair®, Keltrina®, Nedax®), 0.02% deltamethrin (Deltacid®, Pediderm®), and two “natural” products (Piolho e Lêndea®, Pilogenio®). We also tested 5% permethrin (Keltrina Plus®), traditional home remedies and an ivermectin‐based product used in veterinary medicine. Head lice (49–52 per group) were immersed in the compound for 3 min and washed after 20 min to simulate the typical in vivo treatment protocol. Lice were examined for activity up to 24 h using stringent criteria for survival. Results Of the permethrin containing products, highest mortality was observed with Kwell® and Clean Hair® (97.9 and 90.2% after 4 h). Keltrina®, Nedax®, Keltrina Plus®, and the two deltamethrin‐based products showed only a low efficacy of <60% after 4 h. With exception of pure coconut oil (80% mortality after 4 h), home remedies showed a very low efficacy, and both marketed products killed few lice. The ivermectin‐based product caused a mortality of 100% after 4 h. Conclusions Most Brazilian OTC products did not show a satisfactory efficacy against head lice. Resistance may be present. Ivermectin and coconut oil are promising compounds for topical treatment. Laboratory‐based tests should be used to assess resistance patterns and to identify formulations of the active ingredient that increase the efficacy. Standardized testing should be performed before a product is licensed for head lice treatment.