Ciprofloxacin drug interactions

All quinolones interact with multivalent cations, forming chelation complexes resulting in reduced absorption. Major offenders are antacids vitamins containing calcium and iron can also be problematic. All fluoroquinolones interact with warfarin, didanosine (ddi), and phenytoin, resulting in decreased absorption or metabolism. Ciprofloxacin and other second-generation drugs interact with theophylline by decreasing its clearance, which leads to theophylline toxicity. 

About a week later, the patient was admitted to the hospital with acute onset of confusion and possible seizurelike activity. His wife states that he is compliant with medications and even felt well after initiation of antibiotics. Possible ciprofloxacin-induced acute CNS toxicity or drug interaction was suspected, and all his medications were discontinued. Which of the following is the possible explanation for the patient s acute onset of CNS toxicity ... 

B) Acute alcohol withdrawal was precipitated by ciprofloxacin due to an alcohol-drug interaction. 

Drug interactions The effect of antacids and cations on the absorption of these agents was considered above. Ciprofloxacin, ofloxacin and enoxacin can increase the serum levels of theophylline by inhibiting its metabolism. They also may raise levels of warfarin, caffeine and cyclosporine. Cimetidine interferes with the... 

The drug interactions with rifampicin and ciprofloxacin would also need to be taken into account if hormonal methods were used [19, 36]. 

Polk RE. Drug-drug interactions with ciprofloxacin and other fluoroquinolones. Am J Med 1989 87(suppl 5A) 76S-81S. 

Pharmacokinetic interaction the drugs interact remotely from the target site to alter plasma (and other tissue) concentrations so that the amount of the drug at the target site of clinical effect is altered, e.g. enzyme induction by rifampicin will reduce the plasma concentration of warfarin enzyme inhibition by ciprofloxacin will elevate the concentration of theophylline. 

Spivey JM, Cummings DM, Pierson NR. Failure of prostatitis treatment secondary to probable ciprofloxacin-sucralfate drug interaction. Pharmacotherapy 1996 16(2) 314-16. 

Because finasteride and dutasteride are metabolized primarily by CYP3A4, the CYP3A4 inhibitors, such as ritonavir, ketoconazole, verapamil, diltiazem, cimetidine, and ciprofloxacin, may increase the drugs blood levels and, possibly, cause drug-drug interactions. Clinical drug interaction studies have shown no pharmacokinetic or pharmacodynamic interactions between dutasteride and tamsulosin or terazosin, warfarin, digoxin, and cholestyramine. 

Rollof J, Vinge E. Neurological adverse effects during concomitant tteatment with ciprofloxacin, NSAIDS, andchloroquine possible drug interaction. AnnPharmaco er(1993)27, 1058-9. 

The known potential for quinolones to induce seizures suggests that these antibacterials should either be avoided in epileptics, or only used when the benefits of treatment outweigh the potential risks of seizures. Some of the reactions seem to be drug-disease interactions rather than drug-drug interactions, the usual outcome being that the control of epilepsy is worsened. However, it appears that ciprofloxacin may also alter (usually decrease) phenytoin levels, and if this combination is used it would be prudent to consider monitoring phenytoin levels. Enoxacin appears not to alter phenytoin levels. 

Cleary JD. Ciprofloxacin (CEPRO) and pentoxifylline (PTF) a clinically significant drug interaction. Pharmacotherapy (1992) 12, 259-60. 

Loi C-M, Parker BM, Cusack BJ, Vestal RE. Aging and drug interactions.III. Individual and combined effects of cimetidine and ciprofloxacin on theophyUine metabolism in healthy male and female nortsmoktrs. J Pharmacol Exp Ther 99T) 280,627-37. 

Momo K, Homma M, Kohda Y, Ohkoshi N, Yoshizawa T, Tamaoka A. Drug interaction of tizanidine and ciprofloxacin case report Clin Pharmacol Ther 2006) 80, 717-9. 

Drug-drug interactions A case series of four patients reported elevation in clozapine serum levels with the coadministration of perazine, possibly through the inhibition of CYP1A2 [137 ]. Self-medication with St John s wort Hypericum perforatum), an inducer of CYP1A2, led to a reduction in clozapine levels and decompensation in a stable patient [138 ]. An increase in clozapine concentration is reported in a patient being treated for an infection with ciprofloxacin [139 ]. Pregabalin-associated increase of clozapine levels has been described [140 ]. 

Absorption of antimicrobial agents such as fluoroquinolones and tetracyclines that can be bound by divalent and trivalent cations potentially could be compromised by administration with EN formulas containing these cations. The fluoroquinolones (e.g., levofloxacin and ciprofloxacin) have been best studied in this regard, and results of studies are not consistent. Mechanisms for an interaction between fluoroquinolones and EN formulas other than chelation by cations have been postulated.40 Some institutions hold tube feedings for 30 to 60 minutes or more before and after enteral dosages of fluoroquinolones. Because ciprofloxacin absorption has been shown to be decreased with jejunal administration, this drug probably should not be given by jejunal tube.41... 

The fluorinated 4-quinoline antibiotic ciprofloxacin (295) is known to interact with iron-containing drugs and mineral supplements. Stability constants have been determined for complex formation of iron(III) with ciprofloxacin, presumably acting as a bidentate 0,(9-donor, in aque-ous " and in micellar media. 

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