Ciprofloxacininteractions

Ciprofloxacin is an inhibitor of human cytochrome P450 1A2 (CYP1A2) mediated metabolism. Co-administration of ciprofloxacin with other drugs primarily metabolized by CYP1A2 results in increased plasma concentrations of these drugs and could lead to clinically significant adverse events of the co-administered drug.

Table 11: Drugs That are Affected by and Affecting Ciprofloxacin Drugs That are Affected by Ciprofloxacin Drug(s) Recommendation Comments Tizanidine Contraindicated Concomitant administration of tizanidine and ciprofloxacin is contraindicated due to the potentiation of hypotensive and sedative effects of tizanidine. Theophylline Avoid Use (Plasma Exposure Likely to be Increased and Prolonged) Concurrent administration of ciprofloxacin with theophylline may result in increased risk of a patient developing central nervous system (CNS) or other adverse reactions. If concomitant use cannot be avoided, monitor serum levels of theophylline and adjust dosage as appropriate. Drugs Known to Prolong QT Interval Avoid Use Ciprofloxacin may further prolong the QT interval in patients receiving drugs known to prolong the QT interval (for example, class IA or III antiarrhythmics, tricyclic antidepressants, macrolides, antipsychotics). Oral antidiabetic drugs Use with caution Glucose-lowering effect potentiated Hypoglycemia sometimes severe has been reported when ciprofloxacin and oral antidiabetic agents, mainly sulfonylureas (for example, glyburide, glimepiride), were co-administered, presumably by intensifying the action of the oral antidiabetic agent. Fatalities have been reported. Monitor blood glucose when ciprofloxacin is co-administered with oral antidiabetic drugs. Phenytoin Use with caution Altered serum levels of phenytoin (increased and decreased) To avoid the loss of seizure control associated with decreased phenytoin levels and to prevent phenytoin overdose-related adverse reactions upon ciprofloxacin discontinuation in patients receiving both agents, monitor phenytoin therapy, including phenytoin serum concentration during and shortly after co-administration of ciprofloxacin with phenytoin. Cyclosporine Use with caution (transient elevations in serum creatinine) Monitor renal function (in particular serum creatinine) when ciprofloxacin is co-administered with cyclosporine. Anti-coagulant drugs Use with caution (Increase in anticoagulant effect) The risk may vary with the underlying infection, age and general status of the patient so that the contribution of ciprofloxacin to the increase in INR (international normalized ratio) is difficult to assess. Monitor prothrombin time and INR frequently during and shortly after co-administration of ciprofloxacin with an oral anti-coagulant (for example, warfarin). Methotrexate Use with caution Inhibition of methotrexate renal tubular transport potentially leading to increased methotrexate plasma levels Potential increase in the risk of methotrexate associated toxic reactions. Therefore, carefully monitor patients under methotrexate therapy when concomitant ciprofloxacin therapy is indicated. Ropinirole Use with caution Monitoring for ropinirole-related adverse reactions and appropriate dose adjustment of ropinirole is recommended during and shortly after co-administration with ciprofloxacin. Clozapine Use with caution Careful monitoring of clozapine associated adverse reactions and appropriate adjustment of clozapine dosage during and shortly after co-administration with ciprofloxacin are advised. NSAIDs Use with caution Non-steroidal anti-inflammatory drugs (but not acetyl salicylic acid) in combination of very high doses of quinolones have been shown to provoke convulsions in pre-clinical studies and in postmarketing. Sildenafil Use with caution Two-fold increase in exposure Monitor for sildenafil toxicity. Duloxetine Avoid Use Five-fold increase in duloxetine exposure If unavoidable, monitor for duloxetine toxicity Caffeine/Xanthine Derivatives Use with caution Reduced clearance resulting in elevated levels and prolongation of serum half-life Ciprofloxacin inhibits the formation of paraxanthine after caffeine administration (or pentoxifylline containing products). Monitor for xanthine toxicity and adjust dose as necessary. Zolpidem Avoid Use Co-administration with ciprofloxacin may increase blood levels of zolpidem, concurrent use is not recommended. Drug(s) Affecting Pharmacokinetics of Ciprofloxacin Antacids, Sucralfate, Multivitamins and Other Products Containing Multivalent Cations (magnesium/aluminum antacids; polymeric phosphate binders (for example, sevelamer, lanthanum carbonate); sucralfate; Videx ® (didanosine) chewable/buffered tablets or pediatric powder; other highly buffered drugs; or products containing calcium, iron, or zinc and dairy products) Ciprofloxacin should be taken at least two hours before or six hours after Multivalent cation-containing products administration Decrease ciprofloxacin absorption, resulting in lower serum and urine levels Probenecid Use with caution (interferes with renal tubular secretion of ciprofloxacin and increases ciprofloxacin serum levels) Potentiation of ciprofloxacin toxicity may occur. Interacting Drug Interaction Theophylline Serious and fatal reactions. Avoid concomitant use. Monitor serum level Warfarin Anticoagulant effect enhanced. Monitor prothrombin time, INR, and bleeding Antidiabetic agents Hypoglycemia including fatal outcomes have been reported. Monitor blood glucose Phenytoin Monitor phenytoin level Methotrexate Monitor for methotrexate toxicity Cyclosporine May increase serum creatinine. Monitor serum creatinine Multivalent cation-containing products including antacids, metal cations or didanosine Decreased ciprofloxacin absorption. Take ciprofloxacin 2 hours before or 6 hours after administration of multivalent cation containing drugs