Which antibiotic to choose?

Question 1

What factors to consider when deciding if ABX is safe to prescribe?

Answer 1

• Intolerance, allergy and anaphylaxis
• Side effects
• Age
• Renal and Liver function
• Pregnancy and breast feeding
• Drug interactions
  -Risk of Clostridium difficile

Question 2

Confusing cephalosporins - do not follow the naming.

Answer 2

Good for people with penicillin allergy.

Work against some resistant bacteria.

Get into different parts of the body e.g. meningitis.

Question 3

What ABX to use for Gram +ve?

Answer 3

Beta lactams.

Question 4

S. aureus and Group A,C,G, Strep treatment

Answer 4

Flucloxacillin

Question 5

Group A,C,G Strep (throat infection) treatment

Answer 5

PO Penicillin or IV Benzylpenicillin

Question 6

S. pneumoniae treatment

Answer 6

PO Amoxicillin
IV Benzilpenicillin

Question 7

Vancomycin and Teicoplanin IV used to treat

Answer 7

Activity: Gram positive ONLY

Use: Gram positive bacteria resistant to beta-lactams e.g. MRSA, enterococci, some coag neg staph

Use: penicillin allergy.

Question 8

What are the 5 groups of ABX?

Answer 8

1. Inhibitors of cell wall synthesis.
2. Inhibitors of protein synthesis.
3. Inhibitors of nucleic acid synthesis.
4. Anti-metabolites.
5. Inhibitors of membrane function.

Question 9

Macrolides inhibit what?

Answer 9

Protein synthesis.

Question 10

Examples of macrolides?

Answer 10

Clarithromycin and erythromycin PO and IV.

Gram positives (S. aureus, β haemolytic strep) and atypical pneumonia pathogens

Use: penicillin allergy in skin and soft tissue infection

Use: severe pneumonia

Question 11

Lincosamides inhibit what?

Answer 11

Protein synthesis.

Question 12

Example of Lincosamides

Answer 12

Clindamycin (Oral or IV)

Gram positives eg S. aureus, β haemolytic strep , anaerobes
Use: cellulitis (if pen allergy)
Use: necrotising fasciitis (remember Elizabeth…)

TURNS OFF NASTY TOXINS MADE BY Gram positive bugs

Question 13

Tetracyclines inhibit what?

Answer 13

Portein synthesis.

Question 14

Example of tetracyclines

Answer 14

Doxycycline = oral

Activity : Broad spectrum but mainly Gram positive (S. aureus and streps)
Use: cellulitis (if penicillin allergy)
Use: pneumonia

Question 15

What aminoglycoside is used to treat Gram -ve infections?

Answer 15

Gentamicin (IV only)

Activity : Gram negatives and staphs (use synergistically to treat streps)
Use: urinary tract infections (UTIs)
Use: infective endocarditis (synergistically)

Question 16

Quinolones inhibit what

Answer 16

DNA synthesis

Question 17

Example of quinolones

Answer 17

Ciprofloxacin oral and IV

Activity : Gram negative» Gram positive
Use: penicillin allergy
Use: UTIs
Use: intra-abdominal infections

Question 18

Trimethoprim

Answer 18

Anti-metabolite (folate antagonist)

Broad spectrum ABX mainly used for Gram -ve.

To treat UTIs.

Question 19

Nitrofurantoin

Answer 19

Used both for Gram -ve and Gram +ve bacteria.

Treatment of lower UTIs.

Question 20

Co-amoxiclav (Augmentin)

Answer 20

Oral and IV.

S. aureus, streps, enterococci, gram -ve and anaerobes.

Aspiration pneumonia, severe CAP, more resistant urinary organisms.

Question 21

Piperacillin/Tazobactam (Tazocin)

Answer 21

IV

Few gaps, no cover for ESBLs/AmpCs

Use: HA-pneumonia, systemic pseudomonas infections, >65s abdominal infection, immunocompromised.

Question 22

Cefuroxime

Answer 22

IV

Activity: gram positives and gram negatives. No cover for Pseudomonas, anaerobes and enterococci

Use: some surgical prophylaxis, <65s intra-abdominal infections, non-severe penicillin allergy

Question 23

Meropenem

Answer 23

IV

Restricted at STH.

Activity: BROAD. Active against ESBLs/AmpCs.
Use: HAI (sickest, most at risk), resistant gram negatives, immunocompromised

Question 24

Treatment algorithm

Answer 24

Do not start ABX in the absence of clinical evidence of bacterial infection.

Clinical review and decision at 48 and 72 hours.

Question 25

Examples of broad and narrow spectrum ABX

Answer 25

Broad: piperacillin/tazobactam and clindamycin.

Narrow: banzylpenicillin and clindamycin.

Question 26

What is the choice of ABX for lower UTI inf in non-pregnant women aged 16 and over?

Answer 26

Nitrofurantoin 100mg BD for 3 days.

Question 27

What organisms are likely to cause cellulitis?

Answer 27

S. aureus, and beta-haemolytic strep (Group A, C, G)

Question 28

First line treatment for cellulitis?

Answer 28

PO or IV flucloxacillin for 7 days.

Clarithromycin or clindamycin if Allergy to penicillin.