Antibiotics Llewelyn

Question 1

How can we reduce the risk of antibiotics resistance?

Answer 1

give patients less antibiotics.

Question 2

what is giving less antibiotics linked to in terms of clinical outcome?

Answer 2

Reduced risk of mortality with antibiotic de-escalation strategies

Question 3

what are the key agents which are starting to become resistant?

Answer 3

Gentamicin
Ciprofloxacin
Co-amoxiclav
Piperacillin – tazobactam

Question 4

what are the 4 key things to consider antibiotic for choice?

Answer 4

1. microbial aetiology
2. AMR
3. Antibiotic knowledge
4. Patient factors

Question 5

what parts make up AMR?

Answer 5

exposure and epidemiology

Question 6

what makes the microbial aetiology?

Answer 6

focus ‘

exposure

Question 7

What makes up patient factors?

Answer 7

predisposition

severity

Question 8

which antibiotics should you know about?

Answer 8

Penicillins
Cephalosporins
Glycopeptides
Aminoglycosides
Macrolides
Quinolones
Metronidazole
Tetracyclines
Nitrofurantoin
Trimethoprim
Clindamycin

Question 9

Define antimicrobial stewardship

Answer 9

a set of coordinated strategies to improve the use of antimicrobial medications with the goal to enhance patient healthoutcomes, reduceantibiotic resistance, and decrease unnecessary costs

Question 10

how can we revise and review antibiotics better?

Answer 10

Recognise that in hospitals antibiotics are usually started empirically
Think about what evidence you would want to have at review
When you review
Remember antibiotics are harmful
Did they ever have an infection
Are they better now
Do the risks of continuing outweigh the benefits

Question 11

What is amoxicillin and its MOA and indications?

Answer 11

Amoxicillin is a penicillin.
better activity against some Gram negative bacteria). It is used in the treatment of S. pyogenes infections

Mechanism of action
Inhibition of bacterial cell wall synthesis

Question 12

what are the features of a type 1 reaction to beta lactam?

Answer 12

Penicillin Allergy – a class effect
Immediate / Accelerated – Type 1 (0.02% of courses)
0-72 hours after exposure
IgE mediated, mast-cell mediated
Urticaria, wheeze, life threatening

Question 13

what are the features of a delayed reaction?

Answer 13

Delayed – mixed mechanisms (2-3% of courses)
>72 hours after exposure
Will worsen with repeated exposure
Does not become immediate type

Question 14

what are the features of cephalosporin allergy?

Answer 14

Very complicated – lots of potential haptens involved
Not a class effect
Penicillin X-reactivity more with 1st & 2nd generations
Risk ~8% if previous penicillin allergy
Less with 3rd Generation

Question 15

give an example of a macrolide, its MOA and indications

Answer 15

Clarythromycin is a macrolide
used for patients with penicillin allergy for treatment of S. pyogenes infections

Mechanism of action
Inhibition of protein synthesis in the bacterial ribosome (50S subunit)

Question 16

give an example of a glycopeptide, its MOA and indications

and SE

Answer 16

Vancomycin is a glycopeptide. It is active only against Gram-positive bacteria and is active against many resistant strains including Methicillin Resistant S. aureus (MRSA)

Mechanism of action
Inhibits bacterial cell wall (peptidoglycans) formation by a different target to beta lactams

Adverse effects
Nephrotoxic
Ototoxic

Question 17

give an example of tetracycline, its MOA, indications and SE?

Answer 17

Doxycycline is a tetracycline. Good activity against Gram positives (streps and staphs), some Gram negs (haemophilus). Also active against cell-wall deficient bacteria (e.g. Chlamydia) which cause pneumonia and genitourinary infections.

Mechanism of action
Inhibition of protein synthesis in the bacterial ribosome (30S subunit)

Adverse effects
Dyspepsia
Photosensitivity
Avoid in pregnancy / children (teeth)

Question 18

what is the MOA of nitrofurantoin, SE and indications?

Answer 18

Nitrofurantoin – a nitrofuran – only important drug in class. Wide spectrum – esp E. coli and some other enterobacteriaceae, also enterococci, staphs, some streps

Mechanism of action
Complex. Damages bacterial DNA
High resistance threshold?

Adverse effects
V well tolerated
Safe in early pregnancy – avoid late
Avoid in renal impairment – peripheral neuropathy, doesn’t penetrate urine if eGFR low

Question 19

what is 1st line antibiotics for CAP?

Answer 19

amoxicillin

Question 20

what is 1st line antibiotics for HAP?

Answer 20

Co-amoxiclav

Question 21

what is 1st line for meningoencephalitis?

Answer 21

ceftriaxone and dexamethasone

Question 22

what is the 1st line for cellulitis ?

Answer 22

flucloxacillin

Question 23

what is 1st line for abdominal sepsis?

Answer 23

cefotaxime