Permethrin
M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson in Kucers’ The Use of Antibiotics, 2017
Permethrin has the chemical name 3-phenoxyphenylmethyl (±)-cis, trans-3-(2,2-dichloroethenyl),2,2-dimethylcyclopropanecarboxylate; the empirical formula is C21H20Cl2O3; the molecular weight, 391.3. Permethrin is a synthetic pyrethroid, and occurs as a mixture of cis and trans isomers (Taplin and Meinking, 1996). Synthetic pyrethroids are structural derivatives of the naturally occurring pyrethrins, extracted from the flowers of Chrysanthemum cinerarifolium. In some countries, including the United States, only formulations having the 25:75 cis:trans ratio are approved for human use because the cis isomer has higher mammalian toxicity than the trans isomer (Taplin and Meinking, 1996). The cis:trans compositions of permethrin products not approved for human use may differ. Permethrin was first formulated by Michael Elliott and colleagues at the Rothampstead Experimental Station (U.K.) in 1973, and, although it was not the first active synthetic pyrethroid produced, its high activity as an insecticide plus its photostability and thermostability made it suitable for commercial development (Elliott et al., 1973). The chemical structure of permethrin is shown in Figure 210.1.
Rationale and technique of malaria control
David A Warrell, Herbert M Gilles in Essential Malariology, 2017
Deltamethrin, which has a fairly high mammalian toxicity (moderately hazardous; LD50 135 mg/kg), was used at a dosage of 0.05 g/m2 in a field trial in Africa and was safe and effective as a residual spray for at least 2 months. Permethrin, a safer pyrethroid (moderately hazardous; LD50 500 mg/kg), when employed at a dosage of 0.5 g/m2 was fairly effective as a residual spray for about 3 months. The latest synthetic pyrethroid, discovered in the early 1980s and developed as an insecticide for agricultural and public health applications, is lambda-cyhalothrin. The formulations available for residual spraying are 2.5 per cent and 5 per cent emulsifiable concentrate and 10 per cent wettable powder. Application rates are typically in the range of 10–25 mg/m2 or, for prolonged action (6 months), 25–30 mg/m2 are suggested. It is classed as a ‘moderately hazardous’ insecticide, with an LD50 of 56 mg/kg.
Antimicrobials during Pregnancy
“Bert” Bertis Britt Little in Drugs and Pregnancy, 2022
Permethrin is a scabicide used topically as a cream (4 percent). Approximately 2 percent of the topical dose is absorbed systemically. According to the manufacturer, animal teratology studies did not indicate teratogenic potential. Of 106 pregnant women exposed to permethrin in the first trimester, and there was no increased frequency of congenital anomalies (Kennedy et al., 2005). Among 185 infants exposed during the first trimester of pregnancy, the frequency of birth defects was not increased (Mytton et al., 2007). Permethrin is considered the first-line agent for topical treatment of parasitic infections. It is an FDA category B drug.
The progressive alteration of urine metabolomic profiles of rats following long-term and low-dose exposure to permethrin
Published in Biomarkers, 2020
Yu-Jie Liang, Pan Wang, Ding-Xin Long, Hui-Ping Wang, Ying-Jian Sun, Yi-Jun Wu
Pyrethroid insecticides are extensively used in agriculture and public health to control pest insects because of their selective toxicity for insects and relatively low acute toxicity to mammals (Casida and Quistad 1998, Prasanthi and Rajini 2005). However, recent studies show that the insecticides are not completely harmless to human health (Nicolopoulou-Stamati et al. 2016, Chrustek et al. 2018). Permethrin, one of the pyrethroid insecticides, is mainly used for household pest control and malaria eradication (Lawrence and Casida 1983, Soderlund et al. 2002, Bradberry et al. 2005). It can cause a distinct, albeit temporary decrease in the activity of voltage-gated sodium channels in nervous system (Lawrence and Casida 1982, Michelangeli 1990, Vais et al. 2001, DeMicco et al. 2010). Its wide application makes it an increasing risk for human health (Morgan et al. 2007).
Permethrin treated clothing to protect outdoor workers: evaluation of different methods for mosquito exposure against populations with differing resistance status
Published in Pathogens and Global Health, 2018
Stephanie L. Richards, Nwanne Agada, Jo Anne G. Balanay, Avian V. White
Permethrin is used as a repellant and an insecticide and is effective against ticks, mosquitoes and other arthropods [18]. Permethrin is commonly used for pest control in forestry, agriculture, residential, and public health settings, including for head lice and mosquito control [18]. Synthetic pyrethroids, such as permethrin, can be applied to various fabrics (e.g. bed net, clothing) for protection against arthropods. Permethrin is the most commonly used synthetic pyrethroid used in fabric; however, other pyrethroids including bifenthrin, deltamethrin, and cyfluthrin have been tested [19]. Cotton, jute, polyester, and nylon fibers may react differently to insecticides, e.g. deltamethrin showed better results with cotton material compared to other pyrethroids, while cyfluthrin was better for treating jute fibers [8]. The loss of insecticides in treated fabrics can be due to various factors such as: (1) method of impregnation, (2) number of washes, (3) exposure to light, and others [12,20].
‘Loss of efficacy of topical 5% permethrin for treating scabies: an Austrian single-center study’
Published in Journal of Dermatological Treatment, 2022
Damian Meyersburg, Andreas Kaiser, Johann Wolfgang Bauer
The results of our single-center, controlled, randomized, sponsor-free study revealed following results: Two applications of permethrin with a 1-week interval were found to be as less effective as an intensive therapeutic scheme in which affected parts of the body, namely hands and/or feet and/or genitals, were treated additionally daily for 7 days (each 31%). However, at least, both schemes had an impact on mite density and itching intensity. Moreover, a repetition of the treatment with the intensive therapeutic scheme after the failure of a conventional therapy (evaluated at 3-weeks follow-up) was not associated with a better outcome (11% additional responder). In our opinion, a misuse of topical permethrin does not play a role in our patients cohort as (i) permethrin cream had been used (as a standard of care) for over 10 years and has proven efficacy even when applied only once (ii) the amount of consumed cream and accuracy of application was inquired at follow-up questionnaire, (iii) group C patients were on treatment for two ‘proximately’ courses (week 1: conventional scheme; week 4: intensive scheme), a period most likely forgiving misuse of application
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