Lineaz Mechanism of Action

Pharmacology: Pharmacodynamics: Linezolid is an oxazolidinone anti-infective agent. Linezolid inhibits bacterial protein synthesis through a mechanism of action different from that of other antibacterial agents; therefore, Linezolid makes unlikely cross-resistance with other drug classes.
The mechanism of action of Linezolid involves binding to a site on the bacterial 23S ribosomal RNA of the 50S subunit and prevention of formation of a functional 70S initiation complex, which is an essential component of the bacterial translation process. (Linezolid binds selectively to the 50s ribosomal subunit.) Linezolid is bacteriostatic against enterococci and staphylococci and bactericidal against most strains of streptococci.
Linezolid is active in vitro against most strains of Staphylococcus aureus (including methicillin resistant S. aureus [MRSA; also known as oxacillin-resistant S. aureus or ORSA]), Streptococcus agalactiae (group B streptococci, GBS), S. pneumoniae, S. Pyogenes (group A b-hemolytic streptococci, GAS), and vancomycin resistant Enterococcus faecium. Linezolid also has in vitro activity against E. faecalis (including vancomycin-resistant strains), E. faecium (vancomycin-susceptible strains), S. epidermidis (including methicillin-resistant strains [oxacillin-resistant strains]), S. haemolyticus, viridans group streptococci, group G streptococci, Corynebacterium, and Pasteurella multocida.
Resistant to Linezolid has been produced in vitro by serial passage of MRSA (methicillin-resistant Staphylococcus aureus) or enterococci (i.e. E. faecium and E. faecalis).
Pharmacokinetics: Linezolid is well absorbed following oral administration. Peak plasma concentrations occur after 1 to 2 hours. The absolute oral bioavailability is ~ 100%.
Linezolid is readily distributed to well-perfused tissues. Linezolid's volume of distribution at steady state is 40-50 L. It is about 31% bound to plasma protein.
Linezolid is metabolized principally via oxidation to 2 inactive metabolites (an aminoethoxyacetic acid metabolite and a hydroxyethyl glycine metabolite). Linezolid is minimally metabolized and metabolism may be mediated by the cytochrome P-450 (CYP) enzyme system.
Linezolid is eliminated in urine as unchanged drug approximately 30% of an administered dose, as its metabolites approximately 50% of an administered dose and in feces as its metabolites approximately 9% of an administered dose.
Non-renal clearance is approximately 65% of total clearance of Linezolid.
The elimination half-life of Linezolid is 1.5-3 hours for children (1 week-11 years) and 4-5 hours for adults.