Lec 13- Antimicrobial stewardship

Question 1

Why are antibiotics important?

(Antibiotics are good)

Answer 1

• Antibiotics save lives – e.g. 10 year increase in life expectancy in US between 1900-2000; 80m lives saved since 1940
• Antibiotics have revolutionised the practice of medicine – transplants, cancer chemotherapy, prosthetic implants, CF
  
  • Antibiotics underpin alot of treatment regimen

Question 2

Why is antibiotic prescribing important

Answer 2

• Antibiotics are overused
• Antibiotics are perceived as being safe, low risk therapy, ‘just in case’ medicine
• BUT
• Increasing consumption leads to increasing resistance
• Resistance threatens the future of medicine
• Resistance threatens global health

Question 3

O’Neill report

Answer 3

• Monetary incentives have decreased antibiotic prescribing since 2014

Question 4

Where is antibiotic prescribing happening

Answer 4

Question 5

Consumption in secondary care

Answer 5

• SPAUR reports indicated consumption has increased by 12% between 2010-2013, decreased by 5% between 2014-15
• In the West Midlands region, point prevalence surveys demonstrate a median of 31% of patients on antibiotics at any one time
• Literature suggests that between 40-50% of hospital antibiotic prescribing is ‘inappropriate
• Target is to decrease antimicrobial usage by about 1% annual

Question 6

Antimicrobial sterwardship

Answer 6

• ‘An organisational or healthcare-system-wide approach to promoting and monitoring judicious use of antimicrobials to preserve their future effectiveness.’
  
  • Involves any HCP involved in the supply of antimicrobials
• NICE: Antimicrobial stewardship: systems and processes for effective antimicrobial medicine use (August 2015)

Question 7

Methods to change prescribing

Answer 7

*

Question 8

National guidance on stewardship

Answer 8

• Winning Ways’, Department of Health, 2003
• ‘Saving Lives’, Department of Health, 2007
• ‘Start Smart then Focus’ – Department of Health, 2011, 2014
• ‘5 year antimicrobial resistance strategy’ –Department of Health, 2013• NICE guideline (NG 15), 2015

Question 9

Start Smart

Answer 9

• Don’t start antibiotics unless evidence of infection
• Obtain cultures first
• Follow local guidelines
• Document indication and duration – drug chart and notes

Question 10

Evidence of infection

Answer 10

• Signs and symptoms
• Imaging results- a Chest x-ray
• Laboratory results – U&E’s, FBC
• Urine dipstick
  
  • Not for over 65’s- Lots of them have bacteria in the urine

Question 11

Cultures

Answer 11

• Vital for confirming infection
  
  • Causative organism
  • Sensitivity/resistance
• Crucial to check for previous microbiology results
  
  • Colonised with resistant organisms?
  • Past resistant organisms causing infection
• Tissue, urine, sputum, aqueous humour, CSF,

Question 12

Documentation

Answer 12

• Patient journey in the hospital can be fragmented; multiple HCPs can be involved
• Basic documentation can be poor
• Prescribing hierarchy can influence actions or inaction
• Clear documentation of why antibiotics were started and for how long, helps everyone

Question 13

start smart- then focus

Answer 13

• At 48 hours, review results/diagnosis & make a prescribing decision:
  
  • Stop
  • Continue
  • Switch IV to oral
  • Change therapy
  • OPAT- Outpatient Parenteral Antibiotic Therapy
    
    • Often for joint infections

Question 14

Empirical v Directed

Answer 14

• Empirical prescribing:
  
  • Causative organism unknown
  • Source of infection may not be apparent
  • No culture or sensitivity results available
  • Essentially a ‘best guess’
• Directed therapy:
• Organism identified, sensitivity results available +/- source of infection identified
• Usually takes 24-48 hours

Question 15

Course Length

Answer 15

• Depends on infection – stat doses (e.g. chlamydia) to months/years (e.g. TB, osteomyelitis)
• Guidelines will recommend a duration
• Long courses increase risk of side effects, resistance, super-infection
  
  • TB, Oesteomylitis

Question 16

Broad V Narrow

Answer 16

• Gut flora very important to patient health
• Broad spec will wipe out alot of this and increase risk of c.dif

Question 17

IV versus oral

Answer 17

Question 18

Antibiotics are bad

Answer 18

• Collateral damage
• Drug interactions
• Side effects
• Resistance
• Super-infection – e.g. MRSA, Clostridium difficile, fungal infections

Question 19

Super-infections

Answer 19

• Secondary yeast infections after antibiotics
• Colonisation with organisms such as MRSA – e.g. cephalosporins
  
  • Anything that breaches skin barrier- e.g. cannula
• Clostridium difficileinfection

Question 20

MRSA

Answer 20

• Colonisation very common
  
  • Patients screened on admission to hospital
  • Risk factor for surgery
  • MRSA bacteraemias have to be reported; NHS Trusts have targets
  • Number of infections falling since the introduction of hand hygiene campaigns
  • Infection no worse than sensitive S aureus, but fewer treatment options

Question 21

Clostridium difficile infection

Answer 21

• Occurs when abx disrupt gut flora, overgrowth of C. difficile, toxin production
  
  • PPIs, recent surgery, steroids, chemotherapy additional risk factors
• Associated with cephalosporins, quinolones, clindamycin, broad-spectrum abx, e.g. co-amoxiclav, piperacillin/tazobactam
• 20% mortality rate with a severe infection in the elderly; colectomy
• Treated with metronidazole, vancomycin, fidaxomicin
• Relapse common
• Faecal transplants now a viable treatment option- cure rate 80-90%

Question 22

Hospital acquired infections

Answer 22

• The Gram-negatives
• Expanded spectrum beta-lactamase producing organisms (ESBLs)
• Carbapenem-resistant organisms (CROs)- last-resort antibiotic
  *

Question 23

ESBL

Answer 23

• Produced by Gram-negative gut organisms such as E. coli, Klebsiella
• Spread by plasmid transfer, interspecies
• UTIs, abdominal infections, prosthetic material infections
• Capable of destroying penicillins and cephalosporins, often multi-resistant
• Usually treated with carbapenems such as meropenem, imipenem, ertapenem

Question 24

Carbapenem-resistant organisms (CROs)

Answer 24

• Several different resistance mechanisms:
  
  • Reduced entry (porin loss)/ efflux pumps
  • Carbapenemase enzymes, e.g. KPC– Metallo-β-lactamase enzymes
  • Can have multiple resistances in one organism
  • Extremely limited treatment options – older toxic drugs, combination therapy, poor quality evidence

Question 25

Summary

Answer 25

• Antibiotics are life-saving but widely overused
• We need to be much better at preserving their usefulness; the future is uncertain
• Pharmacists have a vital role to play in the stewardship
• Antibiotics are dangerous and risky
• There are bad bugs out there