Lincosamides

Pharmacology of Lincosamide antibiotics (Clindamycin and lincomycin)

1. LINCOSAMIDE ANTIBIOTICS Anusha Shaji , B.Pharm , M.Pharm Assistant Professor Department of Pharmacology Nirmala College of Pharmacy, Muvattupuzha , Ernakulam

2. CLINDAMYCIN Potent lincosamide antibiotic MOA: Inhibit protein synthesis by binding to 50s ribosome Similar in spectrum of activity to erythromycin Clindamycin inhibits most gram positive cocci , C. diphtheriae , Nocardia , Actinomyces and Toxoplasma It has slow action on Plasmodia Pharmacokinetics Oral absorption of clindamycin is good It penetrates into most skeletal and soft tissues, but not in brain and CSF

3. Accumulates in neutrophils and macrophages It is largely metabolized and metabolites are excreted in urine and bile Plasma half life: 3 hours Side effects Rashes, urticaria and abdominal pain Diarrhoea Pseudomembranous enterocolitis due to Clostridium difficile superinfection which is potentially fatal → the drug should be promptly stopped and oral metronidazole (alternatively vancomycin ) given to treat it Thrombophlebitis of the injected vein can occur on i.v . administration

4. Uses Because of the potential toxicity → use of clindamycin is restricted to anaerobic and mixed infections Used for Bact. f ragilis causing abdominal, pelvic and lung abscesses ↓ I t is a first line drug for these conditions, and is generally combined with an aminoglycoside or a cephalosporin Metronidazole and chloramphenicol are the alternatives to clindamycin for covering the anaerobes Skin and soft tissue infections in patients allergic to penicillins can be treated with clindamycin

5. LINCOMYCIN It is the forerunner of clindamycin Similar antibacterial and toxic properties Less potent and produces a higher incidence of diarrhoea and colitis- death have occured ↓ Thus, it has been largely replaced by clindamycin Pharmacokinetics I t is absorbed orally and excreted mainly in bile Plasma half life: 5 hours Dose: 500 mg TDS-QID oral, 600 mg i.m . or by i.v . infusion 6-12 hrly