SOS Topical Clindamycin Mechanism of Action

Antibacterial (Lincosamide).
Pharmacology: Pharmacodynamics: Clindamycin Phosphate is the most widely prescribed topical antibiotic which has been used to help treat pimples/acne for more than 20 years. It has in-vivo activity against all isolates of Propionibacterium acnes. Clindamycin Phosphate is a water soluble ester of the semi-synthetic antibiotic produced by a 7(S)-chloro substitution of the 7(R)-hydroxyl group of the parent antibiotic lincomycin. It is primarily bacteriostatic antibiotic used chiefly in the treatment of some serious infections, notably due to Bacteroides fragilis, and in some staphylococcal and streptococcal infections. It has good activity against a wide range of anaerobic bacteria especially against Gram-positive aerobes. Clindamycin binds to the 50S ribosomal sub-units of susceptible bacteria and prevents elongation of peptide chains by interfering peptidyl transfer, thereby suppressing protein synthesis.
Pharmacokinetics: Small amounts of clindamycin may be absorbed after topical application to the skin; bioavailability from topical preparations of the hydrochloride and phosphate has been reported to be about 7.5% and 2%, respectively. Clindamycin undergoes metabolism, presumably in the liver, to the active N-demethyl and sulfoxide metabolites, and also to some inactive metabolites. About 10% of a dose is excreted in the urine as active drug or metabolites and about 4% in the faeces; the remainder is excreted as inactive metabolites. Excretion is slow and takes place over several days. It is not effectively removed from the blood by dialysis.