Retapamulin(SB-275833) is a topical antibiotic developed by GlaxoSmithKline. Retapamulin(SB-275833) is the first drug in the new class of pleuromutilin antibiotics to be approved for human use.Retapamulin(SB-275833) is marketed as an ointment under the brand names Altabax and Altargo. Retapamulin(SB-275833) is useful for Antibiotics.Retapamulin is a semi-synthetic pleuormutilin prepared by reacting pleuromutilin tosylate with tropine-3-thiol to give a more hydrophobic analogue with a tertiary amine. This enables formulation as a stable hydrochloride salt. Retapamulin is a broad spectrum antibiotic with no cross resistance to existing antibiotic classes, and is the first pleuromutilin approved for human use. Like all the pleuromutilins, retapamulin inhibits protein synthesis by binding to domain V of 23S rRNA.