Antibiotics part 2 Flashcards
In what circumstances would you need to monitor antibiotic therapies?
- narrow therapeutic index
- Risk for toxicity
- Risk for toxicity and poor outcome
Which antibiotic has risk of toxicity?
Aminoglycosides
Which antibiotic has risk of toxicity AND poor outcome?
Vancomycin
What is a peak and when should it be drawn?
Highest concentration achieved during the dosing interval. Should be measured at least 30 minutes after the end of the infusion.
What is a trough and when should it be drawn?
Minimum amount of medication present in the patient before the next dose is given. Ideally, it should be obtained just prior to giving the next dose but can be measured anytime within 30 minutes of a dose.
Level that is drawn at any point during dosing interval.
Random level
Levels drawn at least ____ half life/half lives apart can be used to calculate true peak and trough concentrations.
1 half life
Inhibits bacterial cell wall synthesis and is slowly bactericidal. Covers C. diff when taken orally but NO gram negatives.
Vancomycin
What agent causes red man syndrome?
Vancomycin
True or false: Vancomycin uses time-dependent killing.
True
True or false: It is recommended to obtain a trough and a peak whenever giving vancomycin.
False: Only recommended to obtain a trough (Cmin) because trough monitors efficacy and safety. Only obtain peak (cmax) if performing pt-specific PK.
Which agent targets the 30S subunit?
Tetracyclines
Which agent targets the 50S subunit?
Linezolid, clindamycin, erythromycin, chloramphenicol
Which agent targets both the 30S and 50S subunits?
Aminoglycosides
Which inhibitor of protein synthesis is generally used for empiric double-coverage of gram negative organisms?
Aminoglycosides
Aminoglycosides: Concentration-dependent killing or time dependent?
Concentration-dependent
True or false: It is recommended to obtain both a peak and a trough with aminoglycosides.
True. Peak monitors efficacy; trough monitors safety.
What is the goal amount for aminoglycosides?
<2 mcg/mL
What type of dosing is used with aminoglycosides?
Extended interval dosing (higher than conventional dosing, takes advantage of concentration-dependent killing through optimization of peak:MIC ratios and the post-antibiotic effect.
How do you monitor extended interval dosing?
Obtain random levels at specific time points after infusion of the first dose.
Which agent is effective against ESBL producers?
Aminoglycosides
Which agent is a broad spectrum antibiotic that binds to the 50S subunit and is used only for life-threatening infections?
Chloramphenicol
Blood dyscrasias (anemia, thrombocytopenia, granuloctyopenia) are an adverse reaction for what agent?
Chloramphenicol
What should you monitor in patients receiving chloramphenicol?
CBC
What binds 50S subunit and includes erythromycin, azithromycin, clarithryomycin, and clindamycin?
Macrolides
Which agent has a short half life and is commonly used as a prokinetic?
Erythromycin
Which agent has daily administration and is used for gram negative coverage?
Azithromycin (Z pak)
Which agent has drug-drug interactions of CYP3A4 inhibitor?
Clarithromycin
Which agent covers gram positive organisms and mainly oral anaerobes?
Clindamycin
Which agent covers Staph and enterococcus (including VRE)?
Linezolid
Which agent is contraindicated with SSRIs?
Linezolid
Which agent binds to the 30S subunit and is BACTERIOSTATIC?
tetracyclines
Which agent has the adverse effect of phototoxicity and is contraindicated in children <8 years due to permanent tooth discoloration? (can also cause REVERSIBLE delay of bone growth)
Tetracyclines
What is the most common cause of health-care associated diarrhea in the adult population?
Clostridium difficile
What are the first line and second line treatments for C. difficile?
first line: metronidazole (oral or IV)
second line: Oral vancomycin
Which agent inhibits topoisomerase and DNA-gyrase, thereby inhibiting DNA replication?
Fluoroquinolones
Which agent causes QTc prolongation and has drug-drug interactions with calcium, magnesium, and iron?
Fluoroquinolones
Precaution in children 60 years old with what agent?
Fluoroquinolones
Which agent is rarely used alone, but inhibits RNA polymerase and causes red-orange body fluids and is a CYP450 inducer?
Rifampin
Which agent combination inhibits steps in bacterial folic acid synthesis? It is effective against MRSA.
Trimethoprim and Sulfamethoxazole (TMP-SMZ)
Stevens-Johnson Syndrome, TENS, photosensitivty, and bone marrow suppression are adverse effects of what?
TMP-SMZ
Which agent covers oral and gut anaerobes, including C. diff?
Metronidazole (first line of defense for C.diff)
Describe the two regimens for H. Pylori treatment.
Triple therapy (PPI plus 2 antibiotics) Quadruple therapy (PPI, bismuth, 2 antibiotics)
Which two antibiotics are used in combination to treat H. pylori?
Metronidazole and tetracyclines
