VANCOMYCIN
Vancomycin is a glycopeptide antibiotic that, although not directly involved in the process of anesthesia, plays a crucial role in the perioperative period for preventing and managing infections related to surgical procedures. The importance of vancomycin in the context of anesthesia can be highlighted by the following factors:
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Surgical prophylaxis: Vancomycin is often used as a prophylactic antibiotic in patients at high risk of developing infections caused by methicillin-resistant Staphylococcus aureus (MRSA) or other resistant gram-positive bacteria. By targeting these organisms, vancomycin helps to prevent surgical site infections (SSIs) when administered before the procedure. Proper timing and dosing are essential to ensure adequate tissue concentration during the surgery.
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Treatment of infections: In some cases, vancomycin may be used to treat established infections in the perioperative period, such as wound infections, bacteremia, or endocarditis caused by MRSA or other resistant gram-positive organisms. The choice of vancomycin as a treatment option depends on the suspected or confirmed causative organisms and their susceptibility patterns.
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Resistant organisms: The rise of antibiotic resistance, particularly in gram-positive bacteria such as MRSA, has made vancomycin an important antibiotic for treating infections that are unresponsive to other, more commonly used antibiotics. In the context of anesthesia and surgery, the ability to treat resistant infections is essential for ensuring successful outcomes and minimizing complications.
The mechanism of action of vancomycin can be summarized as follows:
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Binding to the D-Ala-D-Ala terminus of peptidoglycan precursors: Vancomycin binds specifically to the D-alanyl-D-alanine (D-Ala-D-Ala) terminus of the peptidoglycan precursors, which are the building blocks of the bacterial cell wall. By doing so, vancomycin interferes with the proper assembly of these precursors into the mature peptidoglycan structure.
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Inhibition of peptidoglycan synthesis: The bacterial cell wall is primarily composed of a complex structure called peptidoglycan, which provides mechanical strength and rigidity to the cell. The peptidoglycan synthesis process involves the cross-linking of peptidoglycan strands to form a stable and robust cell wall. Vancomycin's binding to the D-Ala-D-Ala terminus of peptidoglycan precursors prevents their incorporation into the growing cell wall and inhibits the activity of transpeptidase and transglycosylase enzymes, which are responsible for cross-linking and polymerization, respectively. This disrupts the synthesis of the peptidoglycan layer.
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Bactericidal effect: The overall effect of vancomycin's action on the bacterial cell wall is bactericidal, meaning it kills the bacteria rather than just inhibiting their growth. By disrupting the synthesis of the peptidoglycan layer, vancomycin weakens the bacterial cell wall, making it susceptible to osmotic pressure and eventually leading to cell lysis and death.
Key points about Vancomycin
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Bactericidal glycopeptide antimicrobial that impairs cell wall synthesis of gram-positive bacteria.
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Particularly useful in staphylococcal infections.
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Part of endocarditis prophylaxis in high-risk patients who are allergic to penicillin.
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Drug of choice in the treatment of infections caused by MRSA.
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May be associated with histamine release and hypotension.
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The elimination half-time is approximately 6 hours.
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The red man syndrome may occur even with slow infusion of vancomycin.
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May cause additive ototoxicity and nephrotoxicity with other ototoxic and nephrotoxic drugs (aspirin, aminoglycosides, cyclosporine, cisplatin, loop diuretics).