Chloramphenicol: Antimicrobial Drug (PDF)

CHLORAMPHENICOL Nitro benzene Derivative MECHANISM OF ACTION  Reversible & bacteriostatic action Interfere...

CHLORAMPHENICOL Nitro benzene Derivative MECHANISM OF ACTION  Reversible & bacteriostatic action Interfere With initiation Of Protein synthesis Misreading of Genetic code Irreversible action Bacteriocidal enzyme catalyse Bond b/w new AA & nascent pepetide Prevent translocation of nascent peptide from acceptor or aminoacyl site (Asite) to peptidyl site (Psite) prevent binding of next aminoacyl tRNA to the ribosomomes Broad Bacteriodes spp.  MECHANISMS OF MICROBIALS RESISTANCE Inactivation of drug by microbial enzy Acetyl transferase enzyme (plasma encoded enzm) No Need to reduce dose in renal impairment Need to reduce dose in hepatic failure  Dose 50 – 100 mg/kg/day in four divided doses  PHARMACOKINETICS Well absorb from gut Achieve high conc. in CNS, even in the absence of inflamed meninges. That’s why use in the treatment of meningitis Dose needs to be lowered in neonates* (low level of glucronosyl-transferase) and cirrhotics Grey Baby syndrome Characterized by ashen grey cyanosis, weakness, respiratory depression, hypotension and shock  ADVERSE EFFECTS 1. Reversible dose dependent anemia caused by blockage of iron incorporation into heme This is due to high concentration of drug in plasma and ferrochelatase is inhibited  Chloramphenicol Chloramphenicol CHL inhibit microsomal enzyme that metabolize several drugs. Like warfarin, phenetoin etc.  Typhus, Rockey mountain spotted fever - Avoid repeated course Use as alternative to B-lactum antibiotics for treatment of meningococcal meningitis who Are hypersensitive to penecillin, or bact. Meningitis caused by penecillin ressistant strain of pneumococci  Use topically in the treatment of eye infection b/c of penetration into ocular tissues and aqueous humor ?