Orally administered drug in a single dose, for scabies is: September 2011

Ans. B: Ivermectin Ivermectin, an antifilaril drug, is given orally in a single dose of 200 mcg/ kg and is highle effective in clearing up scabies Ivermectin/ 22, 23-dihydroavermectin Bla + 22, 23-dihydroavermectin Bib It is a broad-spectrum antiparasitic avermectin medicine. Ivermectin and other avermectins (insecticides most frequently used in home-use ant baits) are macrocyclic lac tones derived from the bacterium Streptomyces avermitilis. Ivermectin kills by interfering with nervous system and muscle function, in paicular by enhancing inhibitory neurotransmission. The drug binds and activates glutamate-gated chloride channels (GluCls). GluCls are inveebrate-specific members of the Cys-loop family of ligand-gated ion channels present in neurons and myocytes. Ivermectin can be given either by mouth or injection. It does not readily cross the blood-brain barrier The main concern is neurotoxicity, which manifest as central nervous system depression, and consequent ataxia, as might be expected from potentiation of inhibitory GABA-ergic synapses. It is traditionally used against worms. It is mainly used in humans in the treatment of onchocerciasis, but is also effective against other worm infestations (such as strongyloidiasis, ascariasis, trichuriasis, filariasis, enterobiasis and some epidermal parasitic skin diseases (EPSDs) including scabies.