Quinolones Flashcards
Which Antibiotics have been linked to deactivation of birth control?
- Rifampin
- Tetracyclines
- Ampicillin
What is the suspected mechanism of antibiotics leading to Birth control deactivation?
gut flora recycles Birth Control into patient’s system; killing gut flora expedites elimination of birth control
What are the 5 most common quinolones?
Ciprofloxacin
Levofloxacin
Moxifloxacin
Ofloxacin
Gemifloxacin
What is the Quinolone mechanism of action?
- DNA gyrase is essential for supercoiling of cellular DNA by a nicking, pass through, and resealing process.
- Quinolones inhibit the enzymatic activity of bacterial DNA gyrase and topoisomerase IV and promote the cleavage of DNA within the enzyme-DNA complex.
Are Quinolones Bacteriocidal or Bacteriostatic?
BACTERIOCIDAL
T/F
Quinolones, along with Aminoglycosides exhibit post-antibiotic-effect.
TRUE
Generally, how would you describe quinolone bioavailabilty?
REALLY high
Why wouldn’t you use Moxifloxacin, Gemifloxacin, or Ciprofloxacin to treat a UTI?
LOW RENAL excretion
What adverse reactions are associated with Quinolone usage?
- Photosensitivity
- QT Prolongation
- Headache, Dizziness, Mental Status Change
- Tendon Rupture (with steroids, over 60yrs)
Why was Gatifloxacin pulled off the market?
- SEVERE HYPOGLYCEMIA
- Kidney dysfunction
- Liver dysfunciton
What does literature say to give for disease states like Spontaneous Bacterial Peritonitis?
Ofloxacin (though more commonly Ciprofloxacin or Levofloxacin is given)
Why don’t you want to give Ciprofloxacin to a pt. already on Theophylline?
Ciprofloxacin can double theophylline levels
Levofloxacin is good though!
Why should you avoid taking Antacids, Iron, or multivitamins when also on a Quinolone?
these drugs bind up the quinolone, diminishing its absorption
Why don’t you want to give Ciprofloxacin to a pt. already on Warfarin?
Increased anticoagulant effect
Levofloxacin is good though!
Why would you want to use Levofloxacin, Gemifloxacin, or Moxifloxacin to treat Staph/Strep infection rather than Ofloxacin or Ciprofloxacin?
Older agents, Cipro/Oflo, don’t cover G+
What bugs are covered by Quinolones?
Staph. (Levo/Gemi/Moxi)
Strep. (Levo/Gemi/Moxi)
Haemophilus influenzae Salmonella Shigella Moraxella catarrhalis Morganella morganii Neisseria gonorrhoeae
Proteus mirabilis/vulgaris
Escherichia coli
Klebsiella pneumonia
SPACE (Cipro/Levo)
SACE (Moxi)
Anaerobes (Moxi)
Atypicals (Levo/Cipro/Moxi)
What is most potent of the quinolones against gram negatives?
What is most potent of the quinolones against pseudomonas?
Ciprofloxacin
Ciprofloxacin
What is the difference in SPACE bug coverage between Ciprofloxacin or Levofloxacin and Moxifloxacin?
SPACE (Cipro/Levo)
SACE (Moxi)
What is the difference in Anaerobe coverage between Ciprofloxacin or Levofloxacin and Moxifloxacin?
Anaerobes only covered by Moxifloxacin
What is the difference in Atypical coverage between Ciprofloxacin or Levofloxacin and Moxifloxacin?
Ciprofloxacin
Levofloxacin
Moxifloxacin
All target Atypicals (Chlamidia, Mycoplasma, Legionella)
Why is it easy to go PO rather than IV when prescribing quinolones?
EXCELLENT BIOAVAILABILITY
What is the difference in uses for Gemifloxacin and Moxifloxacin with Levofloxacin?
Gemi & Moxi dont get strong enough concentration in urine to treat UTI
Levofloxacin will. (Also Levo covers Pseudomonas)
What are mechanisms of resistance for quinolones?
- Volume of usage (used so ofted eg. animal feed, bound to cause resistance)
- altered DNA gyrase
- Altered drug permeability
- Efflux of drug from bacterial cell
What ABX is added to Ciprofloxacin very commonly for skin & soft tissues?
Clindamycin
Which Quinolone has unique indication of intra-abdominal infections?
Which Quinolone wouldn’t you use to treat a UTI?
Moxifloxacin
Moxifloxacin
