Antibiotics I (lecture) Flashcards
What is the cell target of penicillins?
Cell wall synth (Beta lactam)
What is the cell target of Cephalosporins?
Cell wall synth
What is the cell target of monolactams?
Cell wall synth
What is the cell target of Carbapenems?
Cell wall synth
What is the cell target of Glycopeptides?
Cell wall synth
What enzyme is targeted by all B-lactams?
transpeptidase
What amino acid pattern is targeted by B-lactams?
D-Ala-D-Ala
What type of bacteria is primarily targeted by PCN?
Gram +
What are the two penicillinase-resistant penicillins available in the US?
Nafcillin and cloxacillin
Ampicillin and amoxicillin are examples of _______ _______ penicillins?
Extended range
What is the only antipseudomonal pcn available in the US?
Ticarcillin
What pcn is used to target Enterobacter, Proteus, and Pseudomonuas?
Ticarcillin
What is the spectrum of first generation cephalosporins?
Narrow spectrum G+ - staph and strep
What cephalosporin is used prophylactically for surgery?
Cefazolin
What is the difference in use between the generations of cephalosporins?
As we move from 1st to 4th generation the drug goes from primarily targeting G + to G - (i.e. 1st generation is more G + and 4th is more G -)
What classification of Abx end in “-penem”?
Carbapenems
What carbapenem is good for E. coli, S. aureus, Klebsiella, Enterobacter and H. influenzae?
Imipenem
What are two contraindication of Imipenem?
PCN allergy, renal disease
What is the main benefit of Meropenem and Doripenem compared to Imipenem?
Reduced nephrotoxicity
What is the main benefit of Ertapenem compared to Imipenem?
Longer t1/2 - one / day dosing
What generation of cephalosporins is used to target pseudomonas?
3rd
What cephalosporin is used to target N. meningitidis?
Ceftriaxone
What drug class is Aztreonam?
Monobactam
What is used for targeting P. aeruginosa in CF patients?
Aztreonam
What class of Abxs are known to cause Vit-K deficiency (bleeding side effects)?
Cephalosporins
What is a side effect unique to Cefoxitin?
2nd generation Ceph: Inhibit Aldehyde DH –> build up of acetaldehyde
How can ticarcillin lead to cardio toxicity?
Induce hypokalemia
What are the three mechanisms of Beta-lactam resistance?
- B-lactamases
- decreased PBP affinity
- Decreased membrane permeability
What is clavulanic acid and why is it used?
B-lactamase inhibitor given with pcn drugs to overcome resistance
What is the primary resistance factor against B-lactams in gram - bacteria?
Mutations in pore sizes prevents the entry of B-lactams
What are the two Glycopeptide Abx from lecture?
Vancomycin
Teicoplanin
What is the first line Rx against MRSA?
Vanomycin
How is vancomycin typically administered? What is the exception?
IV: It has a low oral availability
The exception is C. difficile colitis
What Abx causes red man syndrome?
Vancomycin
What is the site of action of Vancomycin?
Bind D-Ala-D-Ala tail of NAM –> preventing cross linking of cell wall
What are the adverse effect advantages of Teicoplanin over Vancomycin?
Less histamine release (red man)
Less nephrotoxicity
No ototoxicity
What is the MoA of Daptomycin?
Bind intracellular ion channels and promote ion leakage.
What is first line treatment for Acinetobacter?
Polymixin B
What is the MoA of Polymixins?
Disruption of membranes (G -)
