Antimicrobials 1 Flashcards
Name the primary class of drugs that affect cell wall synthesis.
Beta lactams
What are the four subclasses of beta lactam antibiotics?
Penicillins (4 categories)
Cephalosporins (5 generations)
Carbapenems
Monobactams
To be effective, what four criteria must be met for beta lactams to be effective?
- evade bacterial defenses 2. penetrate outer cell layers to inner cytoplasmic membrane 3. keep the beta lactam ring intact 4. bind to transpeptidase
What is the ultimate method of action of beta-lactams?
They bind to active site of the PBP enzyme to prevent transpeptidation (terminal step in cell wall synthesis)
What is the only true naturally occurring penicillin?
Penicillin G
What two antimicrobials are natural penicillins?
Pen G, Pen V (aka Pen VK)
What are natural penicillins effective against?
sensitive strains of Gram + cocci (Pen G also active against some gram - Neisseria and anaerobes)
Are Natural penicillins narrow or broad spectrum?
Narrow spectrum
What are two Aminopenicillin antimicrobials?
Ampicillin, Amoxicillin
Since activity is extended compared to natural penicillins, aminopenicillins are referred to as what?
Extended spectrum penicillins
better Gram negative coverage than natural penicillins
Aminopenicillins are administered with B-lactamase inhibitors such as? (3 names)
Clavulanate, Sulbactam, or Tazobactam
What is augmentin?
Amoxicillin + Clavulanate
Ampicillin should not be consumed with?
food, because the food binds to the drug and disables it
What are aminopenicillins effective against?
Sensitive Gram + and sensitive Gram - bacteria like H. flu, E. coli, Salmonella, Shigella
What is the drug of choice for standard prophylaxis for infective endocarditis?
Amoxicillin
if allergic, can take cephalexin, or non-B-lactams
What three things interact with Ampicillin activity?
Hydrocortison (inactivates ampicillin), Oral contraceptives (inactivates contraceptive), and Probenecid (slows clearance of ampicillin)
What four antimicrobials are Penicillinase-resistant Penicillins (PRPs)?
methicillin, nafcillin, oxacillin, and dicloxacillin
PRPs are effective against what?
staphylococci, streptococci
NOT enterococci, anaerobic bacteria, gram - cocci or rods
What two PRPs are normally acid stable (given PO) with a reduced risk of interstitial nephritis?
Oxacillin, Dicloxacillin
also undergo biliary excretion, not renal
What is the drug of choice for serious Staphylococcus aureus infections that are non-methicillin resistant (non-MRSA)?
Nafcillin
Naf for Staph