243 Antimicrobial Stewardship Flashcards
Where are anaerobes usually found?
In the mouth, teeth, sinuses, lower bowel
Cause abscesses, dental infections, peritonitis, appendicitis
How can we determine the severity of a chest infection?
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
What are the 6 steps to go through with the antibiotic prescribing decision process?
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?
What are some advantages of MC&S guided therapy?
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
What two antibiotics are nephrotoxic?
Gentamicin
Vancomycin
What class of antibiotics are contraindicated in epilepsy?
Quinolones
Eg. Ciprofloxacin
These lower seizure threshold
Also interact with phenytoin
What two antibiotics should not be used in hepatic impairment?
Rifamicins
Fucidin
Which type of allergic reaction involves IgE antibodies?
Type I “ allergic immediate”
Anaphylaxis, onset in one hour
Which type of allergic reaction involves IgG and IgM antibodies?
Type III Takes over 72 hours to onset Immune complexes involved serious reaction Purporea rash
Warning! Any patient with a history of ___ mediated allergic reactions should not receive a penicillin!!
IgE mediated
Penicillin ABs include: amoxicillin, ampicillin, flucloxacillin, augmentin, piptazo etc
Are other/ idiopathic allergies considered “true allergies?”
No.
Occurs in 1-4% patients receiving penicillins and cephalosporins
What is C diff caused by?
Overgrowth of anaerobic bacteria in the gut
Opportunistic
Associated with previous antibiotic administration/ over use of antibiotics with a broad spectrum
What do macrolides interact with, and why?
Warfarin
Statins (cause muscle wastage)
This is because they’re CYP3A4 inhibitors therefore they increase the levels of these drugs
What does RIFAMPCIN interact with, why?
Warfarin
Theophylline
Progesterones-COC, POP
It’s a potent inducer of CYP450 enzymes
Increased metabolism of drugs metabolised by these enzymes
When should IV (parenteral) antibiotics be reviewed?
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
What patients conditions should be met before switching to oral antibiotics?
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
Who is involved with SURVEILLANCE of antibiotic usage over Europe?
European centre for disease prevention and control (ECDC) (EARS-net: European antibiotic resistance surveillance)
Monitors antibiotic usage and incidence of resistance/ HCAI’s
Is pyelonephritis considered a high risk infection? Can the IV-oral switch be done?
No
Yes it can be switched
What is the oral bioavailability of ciprofloxacin?
100%
Therefore it’s fine to switch to oral
Is osteomyelitis considered high risk? Can an IV- oral switch be done? Why?
Yes
IV oral switch can’t be done
Don’t get enough penetration into bone orally
Is meningitis considered high risk? What about endocarditis?
Yes both
Don’t switch to oral
Is gangrene considered high risk?
Yes
Is community aq and hospital aq pneumonia considered high risk?
No
IV to oral switch can be done
Is severe cellulitis considerd high risk?
Yes
Don’t consider switching unless really have to
What is mediastinitis?
An infection/ inflammation of tissues in the chest
It is considered high risk
When do we monitor peak levels and when do we monitor trough levels in Gentamicin dosing regimens?
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
What is the desired range of trough levels for gentamicin?
Less than 1 mg/ L
What’s the main bacteria causing UTIs?
E.Coli
What’s the main bacteria causing CAP?
Streptococcus pneumonia
What are the 2 main types of bacteria causing Cellulits?
Streptococcus (B-heamolytic streptococci)
Staphylococcus
HAP is usually caused by gram ______ bacilli
Negative
Common causes: Enterobacteriacea Pseudomonas Acineto bacter Staph aureus Legionella
Renal impairment and gentamicin: what’s the deal?
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
What’s the formula for ideal body weight and when in antibiotics is it used?
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!
What’s the formula for corrected body weight then, used for working out dosing of gentamicin in patients that are obese?
Corrected weight = Ideal body weight + [0.4 X (actual body weight - ideal body weight]
If a patient is over 70, what should be the starting dose of gentamicin? What is it usually?
4 mg/kg once daily
Usually it’s 5 mg/ kg
Gentamicin doses should be rounded DOWN to the nearest multiple of ___mg
40 mg
This is because ampoules come as 40mg!- easier dosing
The starting dose of vancomycin in patients with normal renal function is based on what?
Age
Less than 60= 1 mg b.d
60-75= 750 mg b.d
Over 75 = 509 mg b.d
When should the initial pre dose level ( first blood sample for drug levels) be taken for Vancomycin?
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
When taking blood samples for drug levels, how much should be sent?
Send 3.5ml blood in a yellow top (SST) tube
Write time sample taken
Write words PRE dose
When looking at the antibiotic guidelines, do we usually have neutropenic or non neutropenic sepsis?
Non neutropenic
Neutropenic is just for cancer patients with low neutrophils
