VANCOMYCIN - What You Need to Know скачать в хорошем качестве

VANCOMYCIN - What You Need to Know

VANCOMYCIN - What You Need to Know Vancomycin is a bactericidal glycoprotein that binds to the d-Ala-d-Ala terminal of the nascent peptidoglycan pentapeptide side chain and inhibits transglycosylation. Vancomycin is indicated for the treatment of serious or severe infections caused by susceptible strains of methicillin-resistant (beta-lactam-resistant) staphylococci. It is indicated for penicillin-allergic patients, for patients who cannot receive or who have failed to respond to other drugs, including the penicillins or cephalosporins, and for infections caused by vancomycin-susceptible organisms that are resistant to other antimicrobial drugs. Vancomycin is indicated for initial therapy when methicillin-resistant staphylococci are suspected, but after susceptibility data are available, therapy should be adjusted accordingly. Vancomycin is effective in the treatment of staphylococcal endocarditis. Its effectiveness has been documented in other infections due to staphylococci, including septicemia, bone infections, lower respiratory tract infections, skin and skin structure infections. When staphylococcal infections are localized and purulent, antibiotics are used as adjuncts to appropriate surgical measures. Vancomycin has been reported to be effective alone or in combination with an aminoglycoside for endocarditis caused by Streptococcus viridans or S. bovis. For endocarditis caused by enterococci (e.g., E. faecalis), vancomycin has been reported to be effective only in combination with an aminoglycoside. Vancomycin has been reported to be effective for the treatment of diphtheroid endocarditis. Vancomycin has been used successfully in combination with either rifampin, an aminoglycoside, or both in early-onset prosthetic valve endocarditis caused by S. epidermidis or diphtheroids. Specimens for bacteriologic cultures should be obtained in order to isolate and identify causative organisms and to determine their susceptibilities to vancomycin. To reduce the development of drug-resistant bacteria and maintain the effectiveness of vancomycin and other antibacterial drugs, vancomycin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. VANCOMYCIN Mechanism of Action Vancomycin is an antibiotic drug which is structurally classified as a glycopeptide. It mainly acts by prevention of cell-wall biosynthesis of bacteria. It is specially effective against gram-positive bacteria and has been known to be effective against resistant strains of MRSA. Vancomycin is known as the drug of last resort as it generally used when all other treatments have failed. However, bacteria have started developing resistance to vancomycin as well- leading to use of other antibiotics. Vancomycin acts by inhibiting cell wall synthesis of bacteria. Peptidoglycan layer of the cell wall is rigid due to its highly cross-linked structure. During the synthesis of the peptidoglycan layer of bacteria, new building blocks of peptidoglycan get inserted (i.e. monomers of N-acetylmuramic acid and N-acetylglucosamine) into the membrane.Vancomycin inhibit the synthesis of bacterial cell wall phospholipids as well as peptidoglycan polymerization in a time dependent fashion by binding to the D-ala-D-ala side chain of the precursor pentapeptide.This prevent the transglycosylation step in peptidoglycan polymerization . By doing so, vancomycin makes the peptidoglycan layer less rigid and more permeable. This causes cellular contents of the bacteria to leak out and eventually death of the bacteria. Mutations in the transpeptidase enzyme can lead to increased resistance to vancomycin. Adverse Effects more than 10% Bitter taste (PO) Erythematous rash on face and upper body (IV; red neck or red man syndrome; related to infusion rate) Hypotension accompanied by flushing (IV) Nausea and vomiting (PO) 1-10% Chills (IV) Drug fever (IV) Eosinophilia (IV) Rash (IV) Fatique (PO) Peripheral edema (PO) Urinary tract infection (PO) Back pain (PO) Headache (PO) Reversible neutropenia (IV) Phlebitis (IV) less than 1% Nephrotoxicity Ototoxicity (especially with large doses) Stevens-Johnson syndrome Thrombocytopenia Vasculitis