Antibiotics And Modes Of Action Flashcards
What are the five categories of antibiotic agents?
1 Inhibition of cell wall synthesis 2 Altering of bacterial cell membrane 3 Inhibition of protein synthesis 4 Inhibition of DNA or RNA synthesis 5 Inhibition of other metabolic processes
What types of drugs inhibit cell wall synthesis?
Penicillins Cephalosporins Carbapenemss (Monobactems) Glycopeptides (Lipopeptides)
Drugs that inhibit cell wall are also called?
Except glycopeptides
Beta-lactams
Which type of org is inherently resistant to beta lactams?
Orgs without cell walls
Are beta lactams more effective against g+ or g-?
Gram positive
Are beta lactams bacteriocidal or bacteriostatic?
Bacteriocidal
How to beta lactams fxn?
Inhibit cell wall synthesis by inhibiting enzymes needed for peptidoglycan formation
How do glycopeptides like vancomycin fxn?
Interfere with crosslinking of the peptidoglycan
What are the 4 groups of penicillins?
Natural penicillins
Penicillinase-resistant
Extended spectrum
Others
What are the two natural penicillins?
Penicillin G
Penicillin V
What are Penicillin G and penicillin V used for?
Mostly streptococcus, but also gram positive other than staphylococcus and enterococcus
What are the penicillinase-resistant drugs?
Methicillin
Oxacillin
(Nafcillan)
“I met a nasty ox with a beta lactam ring around its neck”
What are the penicillinase-resistant drugs used for?
Gram positive including MSSA but nit Enterococcus
What are the extended spectrum penicillin drugs?
Ampilicillin and amoxicillin
What are extended spectrum penicillin used for?
Gram positive Gram negative (they do not work as well as regular penicillins for GPcocci)
its a little better G neg
What are other penicillins (Piperacillin and Ticarcillin) used for?
Gram negative
What are the four groups of cephalosporins?
First generation
second generation
Third generation
Fourth generation
What makes natural penicillins?
Occur from mold Penicillium notatum
How are penicillinase resistant penicillins produced?
side-chains are added to the drug to allow the antibiotic to be effective against orgs that produce a penicillinase
How do extended-spectrum penicillins functions?
can penetrate the gram negative cell wall
What are penicillin combo drugs?
include a penicillin with a beta lactamase
What are the three Penicillin combo drugs?
augmentim–(amoxicillin with clavulanic acid)
(piperacillin/tazobactam)
(ampicillin/subactam)
what is another name for beta lactamase?
penicillinase
Uses of 1st generation cephalosporins?
GPC, but not MRSA or Enterococcus
Enterobacteriaceae and Anaerobes, but not B. fragillis
better for GP
Uses of 2nd Generation cephalosporins?
BEtter than first generation for for Enterobacteriaceae and other GNB, but less active for Staph
First generation cephalosporins can be inactivated by?
Beta lactamase
SEcond generation is more resistant than first generation to ?
Beta lactamase
First Generation cephalosporin drugs?
Cephalothin
Cefazolin
Cephalexin
Second Generation of Cephalosporin drugs?
Cefoxitin
Cefotetan
Cefuroxime
Third Generation of cephalosporin drugs>
Cefotaxime
Ceftriaxone
ceftazidime
cefixime
4th generation of cephalosporine drugs?
cefepime
Third generation cephalosporin uses?
really good against GNB including Pseudomonas.
Not very good against GP.
Good for multi-drug resistant organisms.
4th generation cephalosporin uses?
GNB that are resistant to 3rd generation.
Carbapenems (beta lactam) drugs?
Imipenem
Meropenem
Doripenem
Ertapenem
Uses of carbapenems?
Really against GNB including Pseudomonas
Good against GP, but not MRSA or VRE
Used when resistant to cephalosporins–mostly GN
Drugs that alter bacterial cell membrane permeability
Bacitracin
Polymyxins
–extremely toxic and used only on the surface of body
Polymyxin drugs?
Polymyxin B and E (colistin)
Use of Bacitracin?
Mostly GP including Staph (for external use only)
Use of Polymyxins?
Mostly GN
used as last resort to resistant GNB
Which drug types inhibit protein synthesis?
Aminoglycosides
Tetracyclines
Macrolides
Choroamphenicol
What drugs are aminoglycosides?
Streptomycin
Gentamycin
Tobramycin
Amikacin
What are special characteristics of aminoglycosides
- There is no oral option because of poor GI absorption.
- Used in combination with beta lactams or vanco to allow bacterial uptake.
- narrow therapeutic index
- toxic to ears and kidneys
- Peaks and troughs are monitored
Use of Aminoglycosides?
Bacteriocidal GP and GN
Tetracycline Drugs
Minocycline
Doxycycline
Use of Tetracyclines
Broad spectrum bacteriostatic
Macrolide drugs
Erythromycin
Clindamycin
Special characteristic of macrolides?
can penetrate WBC so useful in intracellular infections
Uses of macrolides
GP only
These cannot penetrate GN cell wall.
Chloramphenicol special characteristic?
bone marrow toxicity
Choramphenicol mode of actions?
Inhibit protein synthesis
Use of Choramphenicol?
GP and GN
Action of streptomycin?
Inhibit protein synthesis
Action of Bacitracin?
Alter bacterial cell membrane permeability
Action of polymyxin B?
Alter bacterial cell membrane permeability
Action of polymyxin E (Colistin)?
Alter bacterial cell membrane permeability
Action of gentamycin?
inhibit protein sythesis
Action of Tobramycin
Inhibit protein synthesis
Action of Amikacin
Inhibit protein synthesis
What drug type is minocycline?
Tetracyclines
What drug type is doxycycline?
Tetracycline
What drug type is Erythromycine?
Macrolide
What drug type is Clindamycin?
Macrolide
Which drug types inhibit DNA or RNA synthesis?
Fluoroquinolones
Metronidazole
Rifamycin
Use of Fluoroquinolones?
Broad spectrum.
Good for complicated UTI and ear infection.
Not great for Strep or Enterococcus.
Drugs that are Drug type Fluoroquinolone?
Ciprofloxacin
Levofloxacin
Drug that is Drug type metronidazole?
Metronidazole
Rifampin Treatment for?
Tuberculosis
Use of metroniodazole?
Anaerobes
Which drug types inhibit other metabolic processes?
Sulfonamides
Trimethoprim
Nitrofurantoin
Drug action of Sulfoamides?
Inhibits folic acid synthesis
Drug action of Trimethoprim?
Inhibits folic acid synthesis
Drug action of Nitrofurantoin?
Inhibits bacterial enzymes
Use of Sulfonamides ?
GP and GN, but not Psuedomonas
Use of Trimethroprim?
GP and GN
Nitrofurantoin Use?
Most GP and GN UTI drug
