Clindamycin (phosphate) is a lincosamide antibiotic used in the treatment of infections caused by susceptible microorganisms. Clindamycin (phosphate) is a semisynthetic antibiotic derived from lincomycin by 7(S)-chloro-substitution of the 7(R)-hydroxyl group of the lincomycin. Clindamycin is marketed under various trade names including Dalacin (Pfizer), Cleocin (Pfizer), and in a foam as Evoclin (Connetics) and Duac(Stiefel). Clindamycin (phosphate) is used primarily to treat infections caused by susceptible anaerobic bacteria. Such infections might include infections of the respiratory tract, septicemia and peritonitis. In patients with hypersensitivity to penicillins, clindamycin (phosphate) may be used to treat infections caused by susceptible aerobic bacteria as well. It is also used to treat bone infections caused by Staphylococcus aureus. Topical application of clindamycin phosphate can be used to treat moderate to severe acne.