Levofloxin-Natrapharm Drug Interactions

Drugs That Prolong QT Interval: Potential pharmacologic interaction (additive effects on QT interval prolongation). Avoid concomitant use with class IA (e.g., quinidine, procainamide) or class III (e.g., amiodarone, sotalol) antiarrhythmic agents.
Antacids: Potential pharmacokinetic interaction (decreased levofloxacin absorption). Administer levofloxacin at least 2 hours before or 2 hours after antacids containing magnesium or aluminum.
Antiarrhythmic Agents: Potential pharmacologic interaction (additive effect on QT interval prolongation).
Levofloxacin should be avoided in those receiving class IA (e.g., quinidine, procainamide) or class III (e.g., amiodarone, sotalol) antiarrhythmic agents. Pharmacokinetic interaction with procainamide (increased half-life and decreased clearance of procainamide).
Antidepressants: Potential pharmacologic interaction with fluoxetine or imipramine (additive effect on QT interval prolongation).
Antidiabetic Agents: Potential pharmacodynamic interaction (altered blood glucose concentrations and symptomatic hyperglycemia or hypoglycemia) in diabetic patients receiving concomitant levofloxacin and antidiabetic therapy (e.g., insulin, glyburide). Careful monitoring of blood glucose concentrations recommended; discontinue levofloxacin if a hypoglycemic reaction occurs.
Cimetidine: Potential pharmacokinetic interaction (slightly increased levofloxacin AUC and half-life). Not considered clinically important; levofloxacin dosage adjustments are not recommended.
Corticosteroids: Concomitant use of corticosteroids increases the risk of severe tendon disorders (e.g., tendinitis, tendon rupture), especially in geriatric patients older than 60 years of age.
Cyclosporine and Tacrolimus: Possible pharmacokinetic interactions with cyclosporine or tacrolimus (increased AUC of the immunosuppressive agent). Manufacturer of levofloxacin states that dosage adjustments are not required; some clinicians suggest that plasma concentrations of the immunosuppressive agent be monitored if used concomitantly with levofloxacin.
Didanosine: Potential pharmacokinetic interaction (decreased levofloxacin absorption). Administer levofloxacin at least 2 hours before or 2 hours after buffered didanosine (pediatric oral solution admixed with antacid).
Digoxin: Pharmacokinetic interaction unlikely; no clinically important effect on pharmacokinetics of digoxin or levofloxacin.
Iron, Multivitamins and Mineral Supplements: Potential pharmacokinetic interaction (decreased levofloxacin absorption). Administer levofloxacin at least 2 hours before or 2 hours after ferrous sulfate or dietary supplements containing zinc, calcium, magnesium or iron.
Nonsteroidal Anti-inflammatory Agents (NSAIAs): Potential pharmacologic interaction (possible increased risk of CNS stimulation and seizures). Animal studies suggest risk may be less than that associated with some other fluoroquinolones and that risk varies depending on the specific NSAIA.
Probenecid: Potential pharmacokinetic interaction (increased levofloxacin AUC and half-life). Not considered clinically important; dosage adjustments are not required.
Sucralfate: Potential pharmacokinetic interaction (decreased levofloxacin absorption); no pharmacokinetic interaction if given 2 hours apart. Administer levofloxacin at least 2 hours before or 2 hours after sucralfate.
Theophylline: Pharmacokinetic interaction unlikely. However, pharmacokinetic interaction (increased theophylline half-life and increased risk of theophylline-related adverse effects) occurs with some other quinolones. Closely monitor serum theophylline concentrations and adjust theophylline dosage accordingly; consider that adverse theophylline effects (e.g., seizures) may occur with or without elevated theophylline concentrations.
Warfarin: Potential pharmacologic interaction (increased prothrombin time). Monitor prothrombin time or other suitable coagulation tests and monitor for bleeding.