Quinolones and Tetracyclines

Question 1

Quinolones MOA:

Answer 1

Inhibit bacterial DNA gyrase and topoisomerase IV.

• PAE
• Bactericidal

Question 2

Quinolones (5):

Answer 2

• Ciprofloxacin.
• Ofloxacin.
• Levofloxacin.
• Moxifloxacin.
• Gemifloxacin.

Question 3

Quinolones ADRs (10):

Answer 3

• Hypersensitivity.
• Photosensitivity.
• Neutropenia.
• Eosinophilia.
• QT prolongation.
• N/V/D.
• Interstitial nephritis.
• CNS, especially in elderly and AKI.
• Arthropathy (< 18 yrs).
• Tendon rupture (> 60 yrs).

Question 4

Quinolones drug interactions (3):

Answer 4

• Ciprofloxacin can 2x theophylline levels.
• Antacids/iron/sucralfate/multivitamins - wait 2-4 hours.
• Warfarin: Increased INR.

Question 5

Quinolones spectrum of activity:

Answer 5

G+ (except cipro and ofloxacin)
G-:
- Cipro/Levo SPACE
- Moxi SACE 
Anaerobic: Moxi
Atypicals: Levo/Moxi/Cipro cover CML

Question 6

Quinolone that does NOT cover UTIs:

Answer 6

Moxifloxacin.

Question 7

Tetracyclines (6):

Answer 7

• Doxycycline.
• Minocycline.
• Demeclocycline.
• Oxytetracycline.
• Chlortetracycline.
• Tetracycline.

Question 8

Tetracycline MOA:

Answer 8

Reversibly binds to 30S ribosomal subunit.

• Bacteriostatic.
• Absorption increased by food.

Question 9

Tetracycline ADRs (5):

Answer 9

• Photosensitivity.
• Discoloration of developing teeth (during pregnancy - 8 yrs old).
• Reversible DI (demeclocycline).
• Vestibular side effects (minocycline).
• Fanconi-like syndrome.
  
  • N/V, lethargy, polydipsia, polyuria, proteinuria, acidosis, hypokalemia.
  • Expired citric acid formulation.

Question 10

Tetracycline drug interactions (2):

Answer 10

• Decreased absorption when co-administered with cations, antacids, dairy products.
• Enhances warfarin. Increased PT/INR.

Question 11

Tetracycline spectrum of activity:

Answer 11

• Gram +
• Gram -
• Atypicals
• Rickettsia (drug of choice)