6.2 Antimicrobial Stewardship Flashcards
List 4 ways that infectious diseases occur
1) sporadically
2) epidemics
3) pandemics
4) endemic
What kind of antibiotics are penicillin and cephalosporin?
They are both beta-lactam antibiotics; meaning they have a beta-lactam ring and target the penicillin-binding proteins
PBPs; a group of enzymes found anchored in the cell membrane which is involved in the cross-linking of the bacterial cell wall.
Beta-lactam antibiotics tend to be bactericidal
How can drugs for internal infections be administered?
List 5 scenarios where IV administration be preferred
IV, orally or intramuscularly
IV would be preferred if…
1) Oral antibiotics can’t be tolerated (i.e; the person is vomiting)
2) They can’t be absorbed (i.e; malabsorption after intestinal surgery)
3) Impaired intestinal motility (i.e opioid use)
4) No formula available
5) The patient is critically ill (brief delay may be detrimental)
Define the following terms
a) therapeutic range
b) therapeutic index
a) range of concentrations of the drug that are effective without being toxic
b) dose of drug the patient can take that’s proportional to the drugs effective dose
How might one’s gut flora be affected by the use of antimicrobial treatment?
May allow opportunistic pathogens to cause secondary infections (i.e; long term antibiotics may cause overgrowth of C. Albicans and C. difficile)
What is antibiotic stewardship?
Healthcare system wide approach to promoting and monitoring appropriate use of antimicrobial drugs to preserve their future effectiveness.
List the seven principles of antimicrobial stewardship recommended for secondary care
1) Don’t start antibiotics without clinical evidence of a bacterial infection
2) If there’s evidence or suspicion of a bacterial infection, use the local guidelines to begin antibiotic treatment
3) Document on medicines chart and in person’s medical notes the clinical indication, duration or review date, route and dose
4) Obtain cultures (to go from broad->narrow spectrum treatment and to know when to stop antibiotics if a culture suggests an infection is unlikely)
5) Prescribe single-dose antibiotics for surgical prophylaxis (surgical action taken to prevent disease) (if antibiotics have been shown to be effective)
6) Review the clinical diagnosis and the continuing need for antibiotics within 48 hours from the first antibiotic dose and make a clear plan of action
7) Clearly document the review and the subsequent decision in the person’s medical notes
List the five principles of antimicrobial stewardship recommended for primary care
- Only prescribe an antibiotic if there is likely to be a clear clinical benefit 2. Consider a no or delayed antibiotic strategy for acute self-limiting upper resp tract infections 3. Limit prescribing over the phone (except in exceptional cases) 4. Use simple generic antibiotics if possible (avoid broad-spectrum antibiotics if narrow-spectrum remains effective) 5. Avoid widespread use of topical antibiotics
List the 3 main distinctive diagnostic features of Staph.aureus?
1) Production of an extracellular enzyme, coagulase; which converts plasma fibrinogen into fibrin with the assistance of an activator found in plasma
2) Production of thermostable nucleases that break down DNA
3) Production of a surface-associated protein known as clumping factor or bound coagulase that reacts with fibrinogen
How have strains of S.aureus acquired resistance to methicillin?
Strains have acquired the MecA gene which encodes for a novel penicillin-binding protein PBP-2a
This protein shows a low affinity for methicillin and takes over the functions of PBPs when they are inactivated by the antibiotic
Name five different types of infections caused by MRSA, how are infections transmitted?
Transmitted by direct contact
1) Skin
2) Bone and joint
3) Pneumonia
4) Infective endocarditis
5) TSS
How do the majority of community aquired MRSA infections begin?
Who is particularly vulnerable to hospital aquired MRSA?
As skin infections.
Those particularly vulnerable to HA-MRSA include those in ICU, those who have undergone major surgery and those who are immunocomprimised
What are MRSA strains resistant to?
What would you choose to treat an MRSA infection with?
All beta lactam antibiotics and often other agents like aminoglycosides and fluoroquinolones.
Glycopeptides are the agents of choice when treating a systemic MRSA infection.
What can isolates of MRSA have that makes them less susceptible or fully resistant to glycopeptide antibiotics?
Name one antibiotic that can be given to treat glycopeptide resistant MRSA
Thickened cell walls = reduced susceptibility
VanA gene = fully resistant
GR-MRSA can be treated with linezolid
Name two antibiotics that might be given to treat an MRSA infection if the patient is allergic to penicillin
Erythromycin, vancomycin
