Anti Microbial Chemotherapy

Question 1

What factors are important in deciding when to use IV or oral antimicrobials?

Answer 1

Switch patients from IV to oral after 48h, provided that: patient is improving and able to tolerate oral formulation.

Question 2

What is the spectrum of action of different anti microbial groups?

Answer 2

Penicillins 
Cephalosporins 
Aminogycosides eg gentamicin 
Macrolides eg clarithromycin 
Quinolones eg ciprofloxacin
Glycopeptide eg vancomycin
Others eg trimethoprim, clindamycin, doxycycline, rifampicin, metronidazole, linezolid

Question 3

Jar are the advantages and disadvantages of broad and narrow spectrum antibacterials?

Answer 3

Broad spec: increased risk of infection, cheap

Narrow: toxicity, intolerance, specific, expensive

Question 4

Why are drug levels monitored in antibacterial drugs?

Answer 4

In case of toxicity or resistance

Question 5

What are the commonly encountered adverse effects of antomicrobials?

Answer 5

Resistance: MRSA, VRE, ESBL, CPE, C DIFF

Can cause severe invasive infections

Question 6

How does the laboratory influence anti microbial choice?

Answer 6

Gives advice on which antibiotics to use when, and what are suitable alternatives when presented with allergy. Can test for sensitivity

Question 7

How are antiviral and anti fungal agents used in contemporary infection practice?

Answer 7

X

Question 8

What are the principles of prescribing?

Answer 8

1: indications for prescribing
- therapy: empiric or directed
- prophylaxis, primary or secondary

2: diagnosis
- diagnosis of infection, clinics, or lab
- severity assessment

3: patient characteristics

4: antimicrobial selection
- guideline or “individualised” therapy
- likely organism
- empirical v directed
- bactericidal v bacteriostatic
- single agent or combination
- adverse effects potential

Question 9

Why does therapy fail?

Answer 9

Inadequate dose of antibiotic
Inappropriate route
Non compliance
Bacteria walled off
Foreign bodies
Poor penetration of drug to site of infection

Question 10

What is antibiotic stewardship?

Answer 10

Use right Ab for right indication for right duration
only use Ab if suspected or proven infection
Use Ab per guidelines and review with results of microbiology
Review prescriptions regularly and stop asap
Limit use of broad spec blind antibiotic therapy to seriously ill patients