Glycopeptides
Glycopeptides are highly effective bactericidal antibiotics.
Mechanism of action
They inhibit bacterial cell wall synthesis.
Antimicrobial spectrum
They are effective only on G +, especially methicillin resistant staphylococci (oxacilin), enterococci, Streptococcus pneumoniae, Streptococcus pyogenes, Clostridium difficile.
The two basic antibiotics are vancomycin a teicoplanin.
Vancomycin
Vancomycin is Glycopeptides.
Pharmacokinetics
It is not absorbed from the digestive tract - when enteral, it only acts locally, so it is used to treat enterocolitis. It is administered intravenously for systemic effect. It is eliminated by renal excretion in a metabolically unchanged form. Impaired renal excretory function requires dose reduction. It can also accumulate in case of liver insufficiency. The therapeutic window is narrow, sotherapeutic level monitoring'''is appropriate.
Pharmacodynamics
The effect of vancomycin is independent of concentration.
Indication
Vancomycin se užívá k léčbě infekcí vyvolaných citlivými grampozitivními mikroorganismy a anaeroby – např. peritonitidy, sepse, endokarditidy, a k léčbě dalších závažných onemocnění. Perorálně se podává při pseudomembranozní kolitidě. Téměř všechny kmeny stafylokoků jsou na vankomycin dosud citlivé, proto toto antibiotikum patří mezi léky volby při infekcích vyvolaných methicilin-rezistentními stafylokoky (MRSA). Použití vankomycinu by mělo být rezervováno pro případy, kdy nelze podat peniciliny nebo cefalosporiny, popřípadě pro pacienty, kteří na tato antibiotika nereagovali, nebo u nichž je jiná specifická indikace.
Side effects and toxicity
Phlebitis is formed by local irritation, especially after paravenous application. Ototoxicity and nephrotoxicity are directly dependent on plasma concentrations. Therefore, monitoring of plasma levels is recommended. „Red man syndrom“, (flush, itching, hypotension , apparently unsensitized release of histamine from mast cells) may occur with rapid administration . Therefore, vancomycin is also administered by infusion over at least 1 hour.
Contraindication
Vancomycin must not be used in allergies to glycopeptide antibiotics. It must not be used im Caution should be exercised in hearing loss, renal function and pregnancy. Ototoxicity and nephrotoxicity are increased by concomitant administration of other such toxic substances (např. aminoglycosides).
Teicoplanin
Teicoplanin is a glycopeptide with a vancomycin-like spectrum. It does not have cross-resistance, is very well tolerated and is not toxic. It is intended for parenteral administration. The half-life is longer than vancomycin.
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Cathegory:Pharmacology Cathegory:Infectious medicine Cathegory:Microbiology
