Permethrin

Permethrin is a medication and an insecticide. As a medication, it is used to treat scabies and lice. It is applied to the skin as a cream or lotion. As an insecticide, it can be sprayed onto outer clothing or mosquito nets to kill the insects that touch them. Side effects include rash and irritation where it is applied. Use during pregnancy appears to be safe, and it is approved for use on and around people over the age of two months in the United States. Permethrin is in the pyrethroid family of medications. It works by disrupting the function of the neurons of arthropods such as lice, mites, insects, and shrimp, making it highly toxic to these animals. It is also highly toxic to fish. It is of low toxicity to birds and mammals. However, cats are more sensitive to it than other mammals due to much slower metabolism. Permethrin was discovered in 1972. It is on the World Health Organization's List of Essential Medicines. In 2022, it was the 351st most commonly prescribed medication in the United States, with more than 40,000 prescriptions.