Anti-bacterial (B lactams) Flashcards
What are B lactams broadly know to do in their anti-bacterial mechanism?
Inhibit bacterial cell wall synthesis
What four categories can B lactams be divided into?
- Natural
- B-lactamase resistant
- Aminopenicillins
- Anti-pseudomonal
Name two Natural B lactams.
- Penicilin G (Benzylpenicillin)
2. Penicillin V (Phenoxymethyl-penicillin)
Name two B-lactamase resistant B lactams.
- Cloxacillin
2. Flucloxacillin
Name two Aminopenicillin B lactams.
- Ampicillin
2. Amoxicillin
Name one Anti-pseudomonal B lactam.
- Piperacillin
How can Penecillin G (Bezylpenicillin) be administered?
- IV
- IM
How can Penecillin V (Phenoxymethyl-penicillin) be administered?
- Oral
How can Cloxacillin be administered?
- Oral
- IV
- IM
How can Flucloxacillin be administered?
- Oral
How can Ampicillin be administered?
- Oral
- Parenteral
How can Amoxicillin be administered?
- Oral
- IV
- IM
How can Piperacillin be administered?
- Parentral
What is the MOA for Natural B lactams (Penicillin V and Penicillin V)?
- Bactericidal
- Targets growth and replication phase
- Inhibits transpeptidase enzyme (defects and rupturing of cell membrane)
- B-lactamase sensitive
- Acid labile
- Penicillin V less active
What is the MOA for B-lactamase resistant B lactams (Cloxacillin and Flucloxacillin)?
- Bactericidal
- B-lactamase resistance
- Acid stable
- Less active than Penicillin G
What is the MOA for Aminopenicillin B lactams (Ampicillin and Amoxicillin)?
- Bactericidal
- Absorption decreased by food
- Broad spectrum
- Co-amoxiclav (amoxicillin + clavulanic acid = B-lactamse resistant as clavulanic acid inhibits B-lactamse)
- B-lactamase sensitive
- Acid stable
- Cloxacillin + ampicillin = extends spectrum (additive interaction)
What is the MOA for Anti-pseudomonal B lactams (Piperacillin)?
- Bactericidal
What spectrum is Penicillin G (Benzylpenicillin)?
- Gram +ve cocci
- Anaerobes
- Narrow spectrum
- Enterococci (less susceptible) - add aminoglycoside
- Prophylaxis: streptococcal infections, rheumatic fever recurrence and surgical procedures of patients with valvular heart disease
- Penecillin G = initial therapy for serious infections and syphilis
What spectrum is Penicillin V (Phenoxymethyl-penicillin)?
- Streptococcal tonsilitis / pharyngitis
- Less serious infections
- Follow up treatment after serious infections
What spectrum are B-lactamase resistant B lactams (Cloxacillin and Flucloxacillin)?
- Mild B-lactamase +ve staphylococcal infections
What spectrum are Aminopenicillin B lactams (Ampicillin and Amoxycillin)?
- Gram +ve (especially enterococci and listeria)
- Gram -ve (hydrophilic amino-side chain gives penetration)
- Resistant organisms
- Prophylaxis: infective endocarditis
What spectrum are Anti-pseudomonal B lactams (Piperacillin)?
- Pseudomonas aeruginosa
- Extended spectrum
- Gram -ve when synergistic with tazobactam (B-lactamase inhibitor) and Aminoglycosides
What are the adverse effects of Penicillin G (Benzylpenicillin)?
- Neurotoxic effects (convulsions)
- Hypersensitivity
- Crosshypersensitivity
- Mild GIT disturbances
- Neutropaenia and agranulocytosis
- Superinfections
- Bleeding (decreased platelet aggregation)
- Fluid retention
What are the contra-indications of Penicillin G (Benzylpenicillin)?
- Elderly
- Neonates
- Allergic patients
