CEFAZOLIN

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Cefazolin is a first-generation cephalosporin antibiotic that plays a significant role in the perioperative period.

Its use is crucial for preventing and managing infections related to surgical procedures. The importance of cefazolin in the context of anesthesia can be highlighted by the following factors:

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1. Surgical prophylaxis: One of the primary roles of cefazolin in the perioperative period is in preventing surgical site infections (SSIs). Administering cefazolin as a prophylactic antibiotic before surgery, particularly in clean or clean-contaminated cases, helps reduce the risk of postoperative infections by targeting common skin flora and other susceptible bacteria. Proper timing and dosing of cefazolin are essential to ensure adequate tissue concentration during the procedure.

2. Safety profile: Cefazolin is generally well-tolerated and has a favorable safety profile, making it a suitable choice for many patients. However, it is important to consider potential allergies and cross-reactivity with other beta-lactam antibiotics, such as penicillins, when selecting an appropriate prophylactic or treatment regimen.

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The mechanism of action of cefazolin, like other beta-lactam antibiotics, involves the inhibition of bacterial cell wall synthesis. This is achieved through the following steps:

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1. Binding to penicillin-binding proteins (PBPs): PBPs are a group of enzymes located in the bacterial cell membrane that play a critical role in the synthesis and maintenance of the bacterial cell wall. Cefazolin and other beta-lactam antibiotics bind to these proteins, interfering with their normal function.

2. 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. PBPs are responsible for cross-linking the peptidoglycan strands to form a stable and robust cell wall. By binding to PBPs, cefazolin inhibits the cross-linking process, impairing the synthesis of the peptidoglycan layer.

3. Activation of autolytic enzymes: The inhibition of peptidoglycan synthesis can lead to the activation of bacterial autolytic enzymes, which further contribute to the breakdown of the cell wall. This results in bacterial cell lysis and death.

4. Bactericidal effect: The overall effect of cefazolin's action on the bacterial cell wall is bactericidal, meaning it kills the bacteria rather than just inhibiting their growth. This is particularly important for managing infections where the immune system alone may not be sufficient to clear the infection.

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                                                                                         Key points about Cefazolin

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• Cephalosporins are beta-lactam antibiotics that are closely related both structurally and functionally to the penicillins.

 

• Binds to bacterial cell wall membrane, causing cell death.

 

• Cephalosporins are bactericidal antimicrobials that inhibit bacterial cell wall synthesis and have a low intrinsic toxicity.

 

• Cephalosporins can safely be used in patients with history of allergic reaction to penicillins that is NOT an IgE-mediated reaction such as anaphylaxis, urticaria, bronchospasm.

 

• Limited activity against gram-negative organisms.

 

• Peaks 5 minutes after IV administration.

 

• Half-life 90–150 min.

 

• Cefazolin is well absorbed following IM administration.

 

• Cefazolin penetrates bone and synovial fluid well (effective in orthopedic surgery).

 

• Crosses the placenta and enter breast milk in low concentrations.

 

• Excreted almost entirely unchanged by the kidneys.

 

• May cause positive results for Coombs’ test.

 

• Commercially available cephalosporins are ineffective against MRSA.

 

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