Antibiotics

Question 1

What is the mechanism of augmentin/co-amoxiclav

Answer 1

• penicillins
• bactericidal
• interfere with bacterial cell wall synthesis

Question 2

When is co-amoxiclav indicated?

Answer 2

infections due to beta-lactamase-producing strains

eg. community and hospital acquired pneumonia, acute exacerbations of bronchiectasis, COPD, catheter associated UTI

Question 3

When is co-amoxiclav contraindicated

Answer 3

hepatic impairment

When there is penicillin allergy

Question 4

What is the mechanism of teicoplanin?

Answer 4

• a glycopeptide antibiotic
• Bactericidal
• works on aerobic and anaerobic G+ve bacteria
• works on MRSA
• similar to vancomycin but longer duration of action
  (once daily administration after loading dose)

Question 5

When is teicoplanin indicated?

Answer 5

Clotridioides difficile infection (oral)

systemic G+ve infections eg. skin infections, pneumonia, complicated UTI
(IV or IM as not absorbed signif by mouth)

Strep or enterococcal endocarditis (IV)

Bone/joint infections (IV)

Surgical prophylaxis eg. in open fractures (IV)

Question 6

Contraindications of teicoplanin

Answer 6

monitor renal impairment

Question 7

What is the mechanism of gentamicin?

Answer 7

• bactericidal
• broad spectrum except strep and anaerobic
• aminoglycoside binds to 30S ribosomes and inhibits protein synthesis

Question 8

When is gentamicin indicated?

Answer 8

- bacterial eye infections
(eyedrops)
- bacterial otitis externa 
(ear drops)
- G+ve bac endocarditis 
(IM injection or IV)
- Septicaemia, meningitis, hosp pneumonia, endocarditis 
(IV or IM)
- surgery prophylaxis in joint replacement
(IV)
- acute pyelonephritis or catheter associated UTI
(IV)

Question 9

what are the mechanisms of Benzylpenicillin

Answer 9

• bactericidal
• narrow spectrum
• act on bacterial cell wall synthesis

Question 10

When is BenPen indicated?

Answer 10

• mild to moderate infections eg. cellulitis, pneumonia, otitis media, throat infections
  (IM/IV)
• Meningococcal disease
  (IV/IM)

not signif oral absorption so do IM or IV

Question 11

When is BenPen contraindicated?

Answer 11

• penicillin allergy

- renal impairment

Question 12

What is the mechanism of flucloxacillin

Answer 12

• penicillins
• bactericidal
• interfere with bacterial cell wall synthesis

Question 13

When is flucloxacillin indicated?

Answer 13

• infections due to beta-lactamase-producing staph
  eg. otitis externa, etc.
  (oral, IM or IV)
• osteomyelitis (IV)
• staph lung infection in cystic fibrosis (oral)

Question 14

When is flucloxacillin contraindicated?

Answer 14

hepatic impairment

electrolytes can accumulate in high doses of IV.

penicillin allergy

Question 15

What is the mechanism of metronidazole

Answer 15

• high activity against anaerobic bacteria and protozoa
• well absorbed orally, IV usually for severe infections.
  Rectal also an alternative to IV when oral not possible.

Question 16

When is metronidazole indicated?

Answer 16

• H Pylori eradication with clarithromycin and omeprazole (oral)
• fistulating Crohns (oral)
• Bacterial vaginosis (Gardnerella vaginalis)
  (oral or vaginal gel)
• PID (oral)

Question 17

When is metronidazole contraindicated?

Answer 17

• if topical, avoid exposure to strong UV or sunlight

- reduce to 1/3 dose in hepatic encephalopathy