243 Antimicrobial Stewardship

Question 0

Where are anaerobes usually found?

Answer 0

In the mouth, teeth, sinuses, lower bowel

Cause abscesses, dental infections, peritonitis, appendicitis

Question 1

How can we determine the severity of a chest infection?

Answer 1

Use curb 65 score
Tells you whether the person can be treated at home, needs hospital supervised treatment, or needs to be managed in hospital

Question 2

What are the 6 steps to go through with the antibiotic prescribing decision process?

Answer 2

1) diagnosis, rate the severity
2) pick an agent (informed by empirical guidelines, or Mc&S
3) route of admin- IV or oral? Depends on severity
4) dose- based on patient factors
5) duration and review date- IV-oral switch?
6) monitoring- how can we tell if the patients getting better?

Question 3

What are some advantages of MC&S guided therapy?

Answer 3

We can find out what’s causing infection
So we know what to treat it with
Treatment should be more successful
Narrow spectrum antibiotics- less s/es, less risk of nosocomial infections
Can use targetted antibiotic therapy

Question 4

What two antibiotics are nephrotoxic?

Answer 4

Gentamicin

Vancomycin

Question 5

What class of antibiotics are contraindicated in epilepsy?

Answer 5

Quinolones
Eg. Ciprofloxacin
These lower seizure threshold
Also interact with phenytoin

Question 6

What two antibiotics should not be used in hepatic impairment?

Answer 6

Rifamicins

Fucidin

Question 7

Which type of allergic reaction involves IgE antibodies?

Answer 7

Type I “ allergic immediate”

Anaphylaxis, onset in one hour

Question 8

Which type of allergic reaction involves IgG and IgM antibodies?

Answer 8

Type III 
Takes over 72 hours to onset 
Immune complexes involved
serious reaction 
Purporea rash

Question 9

Warning! Any patient with a history of ___ mediated allergic reactions should not receive a penicillin!! 

Answer 9

IgE mediated

Penicillin ABs include: amoxicillin, ampicillin, flucloxacillin, augmentin, piptazo etc

Question 10

Are other/ idiopathic allergies considered “true allergies?”

Answer 10

No.

Occurs in 1-4% patients receiving penicillins and cephalosporins

Question 11

What is C diff caused by?

Answer 11

Overgrowth of anaerobic bacteria in the gut
Opportunistic
Associated with previous antibiotic administration/ over use of antibiotics with a broad spectrum

Question 12

What do macrolides interact with, and why?

Answer 12

Warfarin
Statins (cause muscle wastage)

This is because they’re CYP3A4 inhibitors therefore they increase the levels of these drugs

Question 13

What does RIFAMPCIN interact with, why?

Answer 13

Warfarin
Theophylline
Progesterones-COC, POP

It’s a potent inducer of CYP450 enzymes
Increased metabolism of drugs metabolised by these enzymes

Question 14

When should IV (parenteral) antibiotics be reviewed?

Answer 14

After 48 hours of initiation

Review to see if we can change to a narrower spectrum AB as microbiology have come back to us
Or review to switching to ORAL
But certain conditions must be met before switching to oral antibiotics

Question 15

What patients conditions should be met before switching to oral antibiotics?

Answer 15

Temperature below 37.5 for 24 hours
Conditions improving or stabilising
Signs and symptoms improving
Decreasing ESR/ CRP/ WBC
No potential absorption problems with oral
Is there a suitable oral formulation available
Shouldn’t be suffering from a high risk infection

Question 16

Who is involved with SURVEILLANCE of antibiotic usage over Europe?

Answer 16

European centre for disease prevention and control (ECDC) (EARS-net: European antibiotic resistance surveillance)
Monitors antibiotic usage and incidence of resistance/ HCAI’s

Question 17

Is pyelonephritis considered a high risk infection? Can the IV-oral switch be done?

Answer 17

No

Yes it can be switched

Question 18

What is the oral bioavailability of ciprofloxacin?

Answer 18

100%

Therefore it’s fine to switch to oral

Question 19

Is osteomyelitis considered high risk? Can an IV- oral switch be done? Why?

Answer 19

Yes
IV oral switch can’t be done
Don’t get enough penetration into bone orally

Question 20

Is meningitis considered high risk? What about endocarditis?

Answer 20

Yes both

Don’t switch to oral

Question 21

Is gangrene considered high risk?

Answer 21

Yes

Question 22

Is community aq and hospital aq pneumonia considered high risk?

Answer 22

No

IV to oral switch can be done

Question 23

Is severe cellulitis considerd high risk?

Answer 23

Yes

Don’t consider switching unless really have to

Question 24

What is mediastinitis?

Answer 24

An infection/ inflammation of tissues in the chest

It is considered high risk

Question 25

When do we monitor peak levels and when do we monitor trough levels in Gentamicin dosing regimens?

Answer 25

O.d or B.d dosing= monitor trough levels only

For t.d.s dosing (with MRSA or endocarditis) monitor both peak and trough levels

Question 26

What is the desired range of trough levels for gentamicin?

Answer 26

Less than 1 mg/ L

Question 27

What’s the main bacteria causing UTIs?

Answer 27

E.Coli

Question 28

What’s the main bacteria causing CAP?

Answer 28

Streptococcus pneumonia

Question 29

What are the 2 main types of bacteria causing Cellulits?

Answer 29

Streptococcus (B-heamolytic streptococci)

Staphylococcus

Question 30

HAP is usually caused by gram ______ bacilli

Answer 30

Negative

Common causes:
Enterobacteriacea
Pseudomonas
Acineto bacter
Staph aureus
Legionella

Question 31

Renal impairment and gentamicin: what’s the deal?

Answer 31

Can still use it in renal impairment BUT consider Piptazo (piperacillin with tazobactam)
If severe renal impairment use Piptazo

Remember gentamicin needs therapeutic drug monitoring

Question 32

What’s the formula for ideal body weight and when in antibiotics is it used?

Answer 32

Men: 50 kg + 2.3kg per inch over 5 feet
Women: 45.5kg + 2.3kg per inch over 5 feet

Used to work out corrected weight which is used for obese patients when working out their gentamicin dose!

Question 33

What’s the formula for corrected body weight then, used for working out dosing of gentamicin in patients that are obese?

Answer 33

Corrected weight = Ideal body weight + [0.4 X (actual body weight - ideal body weight]

Question 34

If a patient is over 70, what should be the starting dose of gentamicin? What is it usually?

Answer 34

4 mg/kg once daily

Usually it’s 5 mg/ kg

Question 35

Gentamicin doses should be rounded DOWN to the nearest multiple of ___mg

Answer 35

40 mg

This is because ampoules come as 40mg!- easier dosing

Question 36

The starting dose of vancomycin in patients with normal renal function is based on what?

Answer 36

Age

Less than 60= 1 mg b.d
60-75= 750 mg b.d
Over 75 = 509 mg b.d

Question 37

When should the initial pre dose level ( first blood sample for drug levels) be taken for Vancomycin?

Answer 37

Initial pre dose should be taken before 3rd or 4th dose

Level should be taken 11-12 hours after previous dose for b.d dosing, within one hour before next one is due

Question 38

When taking blood samples for drug levels, how much should be sent?

Answer 38

Send 3.5ml blood in a yellow top (SST) tube

Write time sample taken
Write words PRE dose

Question 39

When looking at the antibiotic guidelines, do we usually have neutropenic or non neutropenic sepsis?

Answer 39

Non neutropenic

Neutropenic is just for cancer patients with low neutrophils