Penicillins Flashcards
Penicillin MOA:
Inhibit bacterial cell wall synthesis.
- Blocks crosslinking of adjacent peptidoglycan strands resulting in lysis.
PCN-binding proteins (PBPs) are targets of Beta-lactam antibiotics.
- Peptidoglycan transpeptidase.
PCN most important route of elimination:
Renal excretion.
- High concentrations in the urine.
PCN absorption:
Food delays and decreases absorption.
- Except amoxicillin, Pen V and carbencillin.
PCN in brain:
Poor distribution to brain and CSF (unless inflammation present).
- Insoluble in lipid.
Most common hypersensitivity reaction:
Maculopapular rash on abdomen/trunk.
Adverse effects of methicillin:
Interstitial nephritis.
Uses for Pen G/VK:
Gram positive organisms:
- Staph - 99% resistant.
- Strep pneumoniae resistance.
- Gonorrhea resistance occurring.
Anti-Staph PCNs (5):
IV: - Methicillin - Oxacillin - Nafcillin PO: - Cloxacillin - Dicloxacillin
Aminopenicillins (2):
- Ampicillin
- Amoxicillin
Aminopenicillins spectrum of activity (8):
Strep, enterococcus, piddly, PEK:
- Streptococcus.
- Enterococcus (drug of choice).
- Haemophilus.
- Salmonella.
- Shigella.
- Proteus.
- E. Cola.
- +/- Klebsiella.
Carboxypenicillins (2):
- Carbenicillin (not made anymore).
- Ticarcillin
Spectrum of activity for carboxypenicilins (4):
- Streptococcus.
- G- piddly.
- G- PEK.
- G- SPACE (pseudomonas req’s high concentrations).
ADRs for carboxypenicillins (3):
- Hypersensitivity.
- Platelet dysfunction (dose dependent).
- Na+ overload.
Ureidopenicillins (2):
- Mezlocillin
- Pipercillin
Ureidopenicillins spectrum of activity (5):
- Bacteriodes fagilis.
- Streptococcus.
- Enterococcus.
- G- PEK
- G- SPACE
