Summary of Anti-mite and louse medications
Malathion is an organophosphate insecticide of relatively low humantoxicity. It is a cholinesterase inhibitor, a diverse family of chemicals that includes sarin and carbaryl. Upon uptake into the target organism, it binds irreversibly to several, random cysteine residues on the cholinesterase enzyme, with a peroxide as the leaving group. The resultant phosphoester group is strongly bound to the cholinesterase, and irreversibly denatures the protein. Malathion in low doses (0.5% preparations) is used as a treatment for head lice & body lice (pediculosis) and scabies.
Permethrin is a medication and chemical widely used as aninsecticide, acaricide, and insect repellent. Permethrin is a first-line treatment for scabies. It is used as a cream. It belongs to the family of synthetic chemicals called pyrethroids and functions as a neurotoxin, affecting neuron membranes by prolonging sodium channel activation. It is not known to rapidly harm most mammals or birds, but is toxic to fish and cats.
Lindane, also known as gamma-hexachlorocyclohexane, (γ-HCH), gammaxene, Gammallin and sometimes incorrectly called benzene hexachloride (BHC), is an organochlorine chemical variant of hexachlorocyclohexane that has been used both as an agricultural insecticide and as a pharmaceutical treatment for lice and scabies. Lindane medications continue to be available in the US, though since 1995 they have been designated "second-line" treatments, meaning they should be prescribed when other "first-line" treatments have failed or cannot be used. Lindane is a neurotoxin that interferes with GABA neurotransmitterfunction by interacting with the GABAA receptor-chloride channel complex at the picrotoxin binding site. In humans, lindane affects the nervous system, liver and kidneys, and may well be a carcinogen. It is unclear whether lindane is an endocrine disruptor.