Pharmacotherapy of Ectoparasitic Infections

Abstract

Epizoonoses such as scabies, lice and cimicosis are common, vexing disorders that occur worldwide. Historically, many treatment modalities have been employed in the management of these disorders, and most of the drugs described in this review are of historical interest and no longer recommended or in widespread use because of their wide spectrum of adverse effects. More recently, reports documenting resistance against various antiectoparasite drugs, complicated and severe courses of the diseases, and adverse effects of drug therapy have prompted the development of new treatment strategies and drugs for optimal disease management. Because the strategies currently recommended for the treatment of ectoparasites differ worldwide, this review proposes a rational approach to selecting the best therapeutic agent by comparing the pharmacokinetics, pharmacodynamics, drug efficacy and adverse effects. A literature search of the currently Internet accessible libraries PubMed, Medline and Ideal library, of citations of articles found there, and from communications with the Federal Institute for Drugs and Medical Devices, Germany, was conducted based on this approach. One major observation of this literature search is that permethrin is the treatment of choice for lice and scabies in the US and in Great Britain, whereas lindane is still recommended for scabies in most other European countries because of its longer-standing record of effectiveness. Although permethrin has not yet been proven to be more effective than lindane in treating infections with these ectoparasites, it currently appears to have the best efficacy versus safety profile of topical treatments for scabies and lice. Ivermectin is a newer oral drug for the treatment of ectoparasites, which has been used with great success in the treatment of onchocercosis and other endoparasites. Although ivermectin appears to be a promising drug, its role in the treatment of ectoparasitic infections will be clarified as more study data become available. Finally, it is important to emphasise the clinical aspects of ectoparasite therapy and that providing the patient with optimal instructions on the use of topical therapeutics is of great importance in avoiding adverse effects and assuring complete removal of the ectoparasite, thereby avoiding the development of drug-resistance.

Bed Bugs: Clinical Relevance and Control Options

“…There are no specific treatments (144), and the clinical reactions tend to be treated empirically as per other insect bites. For cutaneous reactions, topical steroids are used to control inflammation, and systemic antihistamines can provide relief from itching (130,147,262). Antibiotics or topical antiseptic lotions may be prescribed if secondary bacterial infections are present (276) or when the risk of secondary bacterial infections is high, e.g., those with numerous bites and skin excoriation due to scratching (142).…”

Distribution of Lindane in Water, Sediment, and Fish from the Warri River of the Niger Delta, Nigeria

“…The state of California has banned lindane-based products used in the treatment of lice and scabies (5). In Canada and other countries, lindane is generally not used to treat young children, and has voluntarily been withdrawn from the market (6,7).…”

Gravidez, Aleitamento e Fármacos em Dermatologia: Tratamento Tópico

“…19 Quando administrada por via tópica, há uma exposição sistémica mínima e tem sido utilizada de forma segura durante a amamentação e em lactentes com mais de 2 meses de idade. 43 Os dados de segurança são mais escassos em relação a preparações contendo precipitado de enxofre e benzoato de benzilo e não são classificadas pela FDA. 19,35,44 O malatião pode associar-se a depressão respiratória quando aplicado diretamente em recém-nascidos, pelo que, apesar de ser classificado durante a gestação na classe de risco B pela FDA, o seu uso não é recomendado durante a gestação ou amamentação.…”

“…19,35,44 O malatião pode associar-se a depressão respiratória quando aplicado diretamente em recém-nascidos, pelo que, apesar de ser classificado durante a gestação na classe de risco B pela FDA, o seu uso não é recomendado durante a gestação ou amamentação. 35,43,45 O lindano é absorvido para a circulação sistémica e é potencialmente neurotóxico, não devendo por isso ser usado durante a gestação (categoria de risco C pela FDA). 35 O lindano está contraindicado na mulher que amamente por ter sido associado a convulsões e alterações hepáticas no lactente exposto por esta via.…”