Antibiotics Flashcards
Resistant enterobacteriaceae
Esp E. coli and K. pneumoniae
- Extended spectrum beta-lactamase (ESBL) producers - Carbapenemase producing enterobacteriaceae (CPE)
- Kiebsiella producing carbapenemases (KPC)
Antimicrobial stewardship
- The long-term effects of antimicrobial selection, dosage, and duration of treatment on resistance development should be a part of every antimicrobial treatment decision
Amoxicillin
Amoxicillin is a penicillin. Specifically it is an aminopenicillin (good oral bioavailability, longer half-life than penicillin V, better activity against some Gram negative bacteria)
What is amoxicillin used to treat
It is used in the treatment of S. pyogenes infections (sore throat, skin infections), pneumococcal infections (respiratory tract) and coliform infections (urinary tract infection).
Amoxicillin mechanism of action
Inhibition of bacterial cell wall synthesis
Amoxicillin adverse effects
- Allergy
- Damage to commensal microflora
Amoxicillin standard dose
250-1000mg 8 hourly
Amoxicillin oral bioavailability
good
Amoxicillin half-life
1 hr
Amoxicillin excretion
urine
Amoxicillin interactions
Can increase levels of other protein bound drugs
Sore throat infection
Amoxicillin
Common side effect of penicillins in a patient with glandular fever
- Giving penicillins can cause a rash
Pseudomonas treatment
- Piperacillin anti-pseudomonas antibiotic
Penicillin allergy classification
Immediate/accelerated - type 1(0.02% of courses)
Delayed - mixed mechanisms (2-3% of courses)
Penicillin allergy - immediate/accelerated - type 1
- 0-72 hrs after exposure
- IgE mediated, mast-cell mediated
- Urticaria, wheeze, life threatening
Penicillin allergy - delayed mechanisms(2-3% of courses)
> 72 hrs after exposure
- Will worsen with repeated exposure
- Does not become immediate type
Cephalosporin allergy
Very complicated - lots of potential haptens involved
- Not a class effect
- Penicillin X-reactivity more with 1st and 2nd generations
Risk - 8% if previous penicillin allergy
- Less with 3rd generation
Clarythromycin
- Is a similar spectrum of action to amoxicillin and is used for patients with penicillin allergy
What is clarythromycin used to treat
Treatment of S.pyogenes infections(sore throat, skin infections), pneumococcal infections(resp tract) and coliform infections(urinary tract infection)
- Also active against cell-wall deficient bacteria(e.g. chlamydia) which cause penumonia and genitourinary infections
Clarythromycin mechanism of action
- Inhibition of protein synthesis in the bacterial ribosome (50S subunit)
Clarythromycin - oral bioavailability
good
Clarythromycin - metabolism
hepatic