Cell wall inhibitors: Beta Lactam ABX - Cephalosporins

Question 1

Cefazolin

Answer 1

• **Bacteriocidal **
• 1st generation cephalosporin
• **G + **
• parenteral use
• **penetrates most tissues **
• **renal excretion preferred for prophylaxis in sx **

Question 2

Cephalexin

Answer 2

• **Bacteriocidal **
• 1st generation cephalosporin
• **G+ **
• PO
• **penetrates most tissues **
• **renal excretion **

Question 3

Cefoxitin

Answer 3

• **Bacteriocidal **
• 2nd generation cephalosporin
• IV
• **G+ and some G - **
• used in some mixed anaerobic/aerobic infections
• surgical prophylaxis of infections caused by G -
• **particularly resistant to Beta-lactamases **

Question 4

Ceftriaxone

Answer 4

• **Bacteriocidal **
• **3rd gen cephalosporin **
• often in combo with aminoglycoside
• for serious G - infections resistant to other Beta-lactams
  
  • ​(GC, Lyme’s, meningitis)
• **good CNS penetration **
• **= Rocephin **
• IM

Question 5

Ceftazidime

Answer 5

• Bacteriocidal
• 3rd gen cephalosporin
• in combo with aminoglycosides
• for serious G - infections resistant to other Beta-lactams
• Pseudomonas
• **renal excretion **
• **inactivated by extended spectrum Beta-lactamases **

Question 6

Cephalosporins

Answer 6

• **Bacteriocidal **
• cell wall synthesis inhibitors - same as PCN, have Beta Lactam ring (D-ala D-ala analogs)
• **not readily inactivated by Beta-lactamases **
• generations show increasing activity towards G - and decreasing activity towards G+
• **penetrate well into most tissues **
  
  • ​only 3rd Gen penetrate CNS
• **​renal excretion primarily **
• Adverse effects:
  
  • cross reactive w/ other cephalosporins and PCNs
  • **mild nephrotoxicity **
  • **enchances nephrotoxicity of aminoglycosides **