Antimicrobials Flashcards
A bactericidal drug often interferes with ____ or ____ synthesis.
- Cell wall
2. Nucleic acid
A bacteriostatic drug often interferes with ____ and ____.
- Protein synthesis
2. Metabolism
Which drugs are bacteriostatic?
“SulfTetMacChlor”
- Chloramphenicol
- Sulfanomides
- Trimethoprim
- Clindamycin
- Doxycycline
- Macrolides
Which drugs are bactericidal?
“BANF”
- Beta-lactams
- FQ
- Aminoglycosies
- TMS
- Vancomycin
- Metronidazole
What are 2 conditions in which you would want to use a drug that is bactericidal over one that is bacteriostatic?
- Immunosuppressed patient
2. Life-threatening infection
Lowest concentration of an AB that will inhibit growth of a microorganism after incubation with it.
MIC (minimum inhibitory concentration)
Residual effect of antibiotics after concentrations have gone below MIC.
Post-antibiotic effect (PAE)
Which will have more of a post-antibiotic effect, time-dependent antibiotics or concentration-dependent antibiotics?
Concentration-dependent antibiotics
Which is consistent with a time-dependent drug: (1) giving multiple doses daily or (2) giving a single high dose / day?
(1) giving multiple doses daily
Which is consistent with a concentration-dependent drug: (1) giving multiple doses daily or (2) giving a single high dose / day?
(2) giving a single high dose / day
Which drugs are time-dependent?
- Penicillins
- Cephalosporins
- Carbapenems
- Macrolides
- Lincosamides
- Tetracyclines
Which drugs are concentration-dependent?
- Aminoglycosides
- FQ
- Metronidazole
Are beta-lactams bactericidal or bacteriostatic?
Bactericidal
Are beta-lactams time-dependent or concentration-dependent?
Time-dependent
What is the MOA of beta-lactams?
Block cell wall synthesis
Will concentration of a beta-lactam be higher in the urine or in the serum?
Urine
How are beta-lactams excreted?
Via urinary system
Penicillins have excellent efficacy against gram ____ and ____.
- Gram (+)
2. Anaerobes
What makes up Clavamox (2 components)?
- Amoxicillin
2. Clavulanic acid
What makes up Unasyn (2 components)?
- Ampicillin
2. Sulbactam
Which generation of cephalosporin is Cefoxitin?
2nd
Which generation of cephalosporin is Cefepime?
4th
Which generation of cephalosporin is cephalexin?
1st
Which generation of cephalosporin is cefpodoxime?
3rd
Which generation of cephalosporin is cefovecin (convenia)?
3rd
Going from 1st generation cephalosporins to 4th generation cephalosporins, there is increasing action against what type of bacteria?
Gram (-)
What are the ONLY beta-lactams that have post-antibiotic effects?
Carbapenems
True or False: Carbapenems can be administered orally, IV, and SC.
FALSE - Carbapenems cannot be administered orally.
What is most widely used Glycopeptide?
Vancomycin
Is vancomycin bactericidal or bacteriostatic?
Bactericidal
What is the MOA of vancomycin?
Inhibits cell wall synthesis
Is vancomycin time-dependent or concentration-dependent?
Time-dependent
Are FQ bactericidal or bacteriostatic?
Bactericidal
Are FQ time or concentration-dependent?
Concentration-dependent
What is the MOA of FQ?
Disruption of DNA synthesis
Are FQ most effective against gram (+) or gram (-) bacteria?
Gram (-)
True or False: FQs have good efficacy against anaerobes.
FALSE
FQs are highly lipophilic, allow for excellent penetration of ____ and ____ infections.
- Prostatic
2. Respiratory
In which 2 animals should the use of FQs be avoided?
- Cats
2. Young animals
Why should FQs be avoided in cats?
Retinal degeneration
Why should FQs be avoided in young animals (less than 7 months)?
Cartilage/joint toxicity
Which of the following interferes with cytochrome P450 activity, Cephalosporins, Beta-lactams, or FQs?
FQs
Sulfonamides and Trimethoprim both inhibit what?
Folate metabolism
Trimethoprim, unlike the sulfonamides, inhibits what?
Dihydrofolate reductase
The sulfonamides, unlike Trimethoprim, are competitive inhibitors of what?
Pteridin synthase
What are the adverse effects associated with Sulfonamides?
- KCS
- Hepatotoxicity
- Bone marrow suppression
- Polyarthritis
- Immune-mediated thrombocytopenia
What 3 tests would you want to run to monitor side effects associated with sulfonamides?
- CBC
- Shirmer tear test
- Liver panel
What is amikacin?
Aminoglycoside
Name 3 other aminoglycosides.
- Gentamicin
- Tobramycin
- Neomycin
What are 2 adverse effects associated with aminoglycosides?
- Nephrotoxicity
2. Ototoxicity
What is the mechanism of chloramphenicol?
Inhibition of protein synthesis by binding to 50s
Is chloramphenicol bactericidal or bacteriostatic?
Bacteriostatic
What adverse effects are associated with chloramphenicol use in cats and dogs?
Bone marrow suppression (REVERSIBLE)
What is the MOA of tetracyclines?
Inhibition of protein synthesis by binding 30s
What are the adverse effects of tetracyclines?
- Vomiting
- Esophageal strictures (cats)
- Hepatopathy
- Dental discoloration
True or False: Dental discoloration has been reported with all tetracyclines.
FALSE - dental discoloration is NOT well reported with Doxycycline.
What type of AB is Clindamycin?
Lincosamide
What is the MOA of Lincosamides?
Inhibition of protein synthesis by binding 50s
Lincosamides will achieve high concentrations in what?
Leukocytes
What is the spectrum of Lincosamides like Clindamycin?
Gram (+)
Anaerobes
Protozoans (Toxoplasma, Neospora)
What is azithromycin?
Macrolide
Name 2 other Macrolides.
- Clarithromycin
2. Tylosin
What is the MOA of the Macrolides?
Inhibit protein synthesis by binding 50s
The Macrolides achieve high concentration in what?
Tissues
What is the spectrum of the Macrolides?
Gram (+) / some gram (-)
Mycobacterium
