Antibiotics

Question 1

Empiric therapy commenced within 30 mins of presentation if organism unknown.

Answer 1

Ceftriaxone 4g IV daily
OR
Cefotaxime 2 g IV, 6-hourly

– If L. monocytogenes suspected, add:
Benzylpenicillin 2.4 g IV, 4-hourly
AND
Amoxy/ampicillin 2 g IV, 4-hourly.

– If Gram-positive diplococci seen OR CSF pneumococcal antigen assay positive, OR if the patient has been heavily pretreated with a beta lactam, add:
Vancomycin 12.5 mg/kg up to 500 mg IV, 6-hourly (monitor blood levels and adjust dose accordingly)

Question 2

List prophylactic measures with diagnosis of meningitis

Answer 2

Notifiable disease

Treat contacts with rifampicin 600mg for 4 days

Vaccinated (meningococcal, HiB)

Question 3

ABx therapy for H influenzae

Answer 3

Ceftriaxone
OR
Cefotaxime

Question 4

ABx therapy for N. meningitidis

Answer 4

Benzylpenicillin
OR
If penicillin hypersensitivity
Cefotaxime or Ceftriaxone

Question 5

ABx therapy for S. Penumoniae

Answer 5

Penicillin G
OR 
if penicillin hypersensitivity:
Cefotaxmine
OR Ceftriaxone

Question 6

ABx therapy for L. monocytogenes

Answer 6

Ampicillin
AND
Gentimicin

Question 7

What’s in augmentin and MoA?

Answer 7

Amoxycillin 875g
- B lactam antibiotic - ring binds PBP and prevents cross linking of peptidoglycan cell wall (interferes with bacterial cell wall synthesis)
Clavulanic Acid 125g
B lactamase inhibitor - against resistant bacteria that produce enzyme that degrades B lactam ring

Question 8

What is triple therapy?

Answer 8

Used to treat H pylori

Omeprazole 20mg bd 7 days
Amoxycillin 1g bd 7 days
Clarithromycin 500mg bd 7 days

If penicillin hypersensitivity, replace amox with Metronidazole 400mg bd

Question 9

What is the therapy for resistant H.pylori?

Answer 9

Quadruple therapy regimen [7-14days]
(Success rates 80-85%)
PPI (standard dose) bd
Metronidazole 400mg orally tds
Bismuth 120mg qid
Tetracycline 500mg  qid

Rifabutin based triple therapy 
(Success rates of 60-70%)
Amoxycillin 1g bd for 7 days
PPI (standard dose) bd for 10days
Rifabutin 150 mg bd for 10 days