Review of ivermectin in scabies.
Currently available topical medications for scabies are messy and need prolonged application. This leads to poor patient adherence. Emerging drug resistance to topical scabicides has made eradication of scabies difficult. Availability of an effective oral scabicidal agent, ivermectin (Ivm), opens a new era in the management of scabies. This review summarizes the published literature on the use of ivermectin in the treatment of scabies. A single oral dose of ivermectin of 200 mg/kg body weight is very effective in the treatment of human scabies. A second dose 7-10 days later substantially improves the cure rate. This suggests that ivermectin may not be effective against all the stages in the life cycle of the parasite. Endemic and epidemic scabies in institutions are better treated with Ivm. Crusted scabies ideally should be treated with a combination of Ivm and topical scabicides. Other standard measures and precautions should be taken. Additional controlled studies using a higher single oral dose or using parenteral or topical forms of Ivm are needed. The safety of Ivm in children less than 5 years old and in pregnant women has to be established. The U.S. FDA has not yet approved the drug for the treatment of human scabies.