Antibiotics

Question 1

Describe the MOA of the main antibiotic classes.

Answer 1

1. Beta-lactams (penicillins, cephalosporins, carbapanems, monobactams): inhibit penicillin binding proteins, preventing cross-linking of cell wall peptidoglycan layer
2. Glycopeptides: bind cell wall amino acids, preventing
   peptidoglycan chain elongation
3. Tetracyclines, macrolides, aminoglycosides: inhibit protein synthesis
4. Quinolones: inhibit DNA replication

Question 2

Describe the MOA of co-amoxiclav

Answer 2

i) AMOXICILLIN: B-lactam - inhibits peptidoglycan cell wall synthesis
ii) CLAVULANIC ACID: B-lactamase inhibitor

Question 3

Describe the MOA of tazocin.

Answer 3

i) PIPERACILLIN: B-lactam - inhibits peptidoglycan cell wall synthesis
ii) TAZOBACTAM: B-lactamase inhibitor

Question 4

What is the MOA of gentamicin? Name 2 characteristic ADRs.

Answer 4

Aminoglycoside - protein synthesis inhibitor.

ADRs:

• ototoxicity (irreversible, due to auditory or vestibular n. damage)
• nephrotoxicity (acute tubular necrosis)

Question 5

What are the 1st line antibiotics to treat uncomplicated UTI in females? What is their MOA?

Answer 5

3 days:

1. NITROFURANTOIN - reduced form is highly reactive, damage bacterial DNA, ribosomal proteins…
2. TRIMETHOPRIM - inhibits dihydrofolate reductase, inhibiting folic acid synthesis

Question 6

Which antibiotic would you use to treat meningococcal meningitis? What is its MOA?

Answer 6

CEFTRIAXONE: B-lactam (cephalosporin) - inhibits peptidoglycan cell wall synthesis.

Can penetrate CSF.

Question 7

Name characteristic ADRs of nitrofurantoin.

Answer 7

1. Pulmonary fibrosis/ILD
2. Hepatitis
3. Peripheral neuropathy (stocking-glove pattern)

Question 8

Describe the MOA of vancomycin.

Answer 8

GLYCOPEPTIDE: binds cell wall amino acids, preventing peptidoglycan chain elongation.