OBJECT DRUGS

Quinolones:

• Ciprofloxacin (Cipro, etc.)
• Enoxacin (Penetrex)
• Gemifloxacin (Factive)
• Levofloxacin (Levaquin, etc.)
• Lomefloxacin (Maxaquin)
• Moxifloxacin (Avelox, etc.)
• Norfloxacin (Noroxin)
• Ofloxacin (Floxin, etc.)
• Sparfloxacin (Zagam)

PRECIPITANT DRUGS

Binding Agents:

• Antacids
• Calcium Polycarbophil (FiberCon)
• Didanosine (Videx, etc.)
• Iron Products
• Sucralfate (Carafate)
• Zinc

Comment:

The absorption of quinolones is markedly reduced by agents containing cations such as aluminum, magnesium, and to a lesser extent, iron and calcium. Ciprofloxacin and norfloxacin appear more susceptible to this effect than lomefloxacin or ofloxacin; iron has little effect on lomefloxacin and ofloxacin. Limited evidence suggests that the absorption of some quinolones may be affected by multivitamins with minerals.

Class 3: Assess Risk & Take Action if Necessary

• Consider Alternative: Calcium carbonate does not impair quinolone absorption as much as aluminum-magnesium antacids, but it would still be prudent to separate doses. Gatifloxacin absorption does not appear to be affected by calcium carbonate. Enteric coated didanosine (Videx EC) does not interact.
• Circumvent/Minimize: Giving the quinolone 2 hours before or 6 hours after the cation minimizes the interaction.
• Monitor: Watch for reduced quinolone antibiotic efficacy in patients taking di- or trivalent cations.