Antibiotics: Cell Wall

Question 1

B-lactams MOA

Answer 1

Includes:
* Penicillins
* Cephalosporins
* Monobactams
* Carbapenems

MOA: Inhibits transpeptidase (PBP) so inhibits cross linking

Question 2

Penicillins

Answer 2

MOA: xPBP xCross linking

USE: GRAM POS / syphilis

Question 3

Methicillin, oxacillin, dicloxacillin, nafcillin

Answer 3

MOA: xPBP xCross linking

USE: mainly for STAPH AUREUS (MSSA)

Question 4

Amoxicillin, ampicillin

Answer 4

MOA: xPBP xCross linking

USE:
-GRAM POS: Strep / Listeria
-GRAM NEG: Hae. influ. / E. coli / Proteus

= HELPS

Question 5

Clavulanic acid, tazobactam

Answer 5

Only used in combination with e.g. amoxicillin

USE:
-GRAM POS
-GRAM NEG: HNPEK (HEPNK)
-Anaerobes

Haemophilus influenza, Neisseria ssp. Proteus mirabilis, Escherichia coli, Klebsiella

Question 6

Piperacillin

Answer 6

Activity against several gram-negative rods including Pseudomonas
-Amp + (more) GNRs (HNPEK/CaPES)

• Citrobacter
• (Acinetobacter; poor activity)
• Pseudomonas
• Enterobacter
• Serratia

Question 7

Penicillins AE

Answer 7

-Hypersensitivity reactions (rash, fever, joint swelling, pruritus, ana shock, leukopenia)
-GI distress (diarrhea)

Question 8

Cephalosporins

Answer 8

Similar to penicillins but more stable to b-lactamases (broader spectrum of activity)

Similar MOA to penicillins

Question 9

Cefazolin, cephalexin (1st gen)

Cefuroxime, cefoxitin, cefotetan (2nd gen)

Ceftriaxone, cefotaxime, ceftazidime (3rd gen)

Answer 9

1gen - Strep / Staph / PEK / surgical pro

2gen - HNPEK (crosses BBB for meningitis)

3gen - CAPES

Question 10

Cefepime (4th gen)

Answer 10

IV only, nosocomial infections

Question 11

Ceftaroline (5th gen)

Answer 11

Broad spec, Gram + and Gram -

IV only

Question 12

Cephalosporins AE

Answer 12

-Hypersensitivity reactions
-GI distress
-Intolerance to alcohol
-Potential nephrotoxic (1st gen mainly)

G is HIP

Question 13

Monobactams - Aztreonam

Answer 13

Same MOA and AE as penicillins

Use if allergic to penicillin and cephalosporin and you need activity against a gram-negative rod

HNPEK + CaPES (only gram -)

Question 14

Carbapenems - Meropenem

Answer 14

Same MOA and AE as penicillins

Broadest spec, gram - and gram +

Question 15

Vancomycin

Answer 15

MOA: Bind to D-Ala-D-Ala to prevent their cross-linking

USE:
-Gram-positive: Streptococci, MRSA, Enterococci, Clostridium difficile

NOT DOC, 2nd line

AE:
-Hypersensitivity (“Vancomycin flushing syndrome”)
-Ototoxicity
-Nephrotoxicity

Question 16

Daptomycin

Answer 16

MOA: Interfere with inner membrane, create channels through which bacterial electrolytes leak, disturb homeostasis

USE: Gram + only

AE:
-Musculoskeletal: muscle pain/weak (monitor phosphokinase)

DI: Statins