Scabies oral drug of choice:

Ref: Katzung, 14th ed. pg. 939, 1075; KDT, 6th ed. pg. 864* Scabies is caused by an ectoparasite sarcoptes scabei. It is highly contagious. The mite burrows through the epidermis, laying eggs which form papules that itch intensely.* Most common site of entry- finger webs.* Drugs used are:# Permethrin 5%: broad spectrum and potent insecticide, currently most efficacious.* It is DOC for scabies.* MOA: It causes neurological paralysis in insects by delaying depolarization.* Single application needed in most cases.* Very less toxicity; 100% cure rate.# Lindane: another broad spectrum insecticide.Efficacy lower than permethrin.MOA: kills lice and mites by penetrating through their chitinous cover and affecting the nervous system.# Benzyl benzoate: Oily liquid with a faint aromatic smell.It is applied over face and neck after a bath. A second coat is applied next day which is washed after 24 hours.# Crotamiton# Sulfur# Ivermectin: Highly effective in scabies and pediculosis as well. Oral DOC in scabies.* It is the only ORALLY administered drug which is used for scabies (ectoparasitosis)* A single dose of 0.2mg/kg has cured almost 90-100% of population.* It is contraindicated in children <5 yrs, pregnant and lactating women.