Clindamycinsulfoxide is an active metabolite of the antibiotic clindamycin . It is formed via S-oxidation of clindamycin primarily by the cytochrome P450 (CYP) isoform CYP3A4. Clindamycinsulfoxide inhibits the growth of P. prevotti, B. fragilis, and C. sordelli in vitro with MIC values of 2, 2, and 1 mg L, respectively.