Ciprofloxacin

7 DRUG INTERACTIONS 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 8: 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 [see Contraindications ( 4.2 )] . 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 [see Warnings and Precautions ( 5.10 )]. 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) [see Warnings and Precautions ( 5.12 ) and Use in Specific Populations ( 8.5 )]. 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 [see Adverse Reactions ( 6.1 )]. 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 [see Warnings and Precautions ( 5.16 )] . 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 [see Clinical Pharmacology ( 12.3 )] . 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 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 ( 7 ) Warfarin Anticoagulant effect enhanced. Monitor prothrombin time, INR, and bleeding ( 7 ) Antidiabetic agents Hypoglycemia including fatal outcomes have been reported. Monitor blood glucose ( 7 ) Phenytoin Monitor phenytoin level ( 7 ) Methotrexate Monitor for methotrexate toxicity ( 7 ) Cyclosporine May increase serum creatinine. Monitor serum creatinine ( 7 )

Ciprofloxacin tablets are a fluoroquinolone antibacterial indicated in adults (18+ years) and select pediatric patients for treating infections including: skin/skin structure infections, bone and joint infections, complicated intra-abdominal infections, infectious diarrhea, typhoid fever, uncomplicated gonorrhea, inhalational anthrax post-exposure, plague, chronic bacterial prostatitis, lower respiratory tract infections, urinary tract infections, and acute sinusitis. The label emphasizes reserving use for patients with no alternative treatment options for certain conditions like acute uncomplicated cystitis and acute bronchitis exacerbations due to serious adverse risks.

2 DOSAGE AND ADMINISTRATION Ciprofloxacin injection should be administered intravenously at dosages described in the appropriate Dosage Guidelines tables. Adult Dosage Guidelines Infection Dose Frequency Duration Skin and Skin Structure 400 mg every 8 to 12 hours 7 to 14 days Bone and Joint 400 mg every 8 to 12 hours 4 to 8 weeks Complicated Intra-Abdominal 400 mg every 12 hours 7 to 14 days Nosocomial Pneumonia 400 mg every 8 hours 10 to 14 days Empirical Therapy In Febrile Neutropenic Patients 400 mg and Piperacillin 50 mg/kg every 8 hours every 4 hours 7 to 14 days Inhalational anthrax (post-exposure) 400 mg every 12 hours 60 days Plague 400 mg every 8 to 12 hours 14 days Chronic Bacterial prostatitis 400 mg every 12 hours 28 days Lower Respiratory Tract 400 mg every 8 to 12 hours 7 to 14 days Urinary Tract 200 to 400 mg every 8 to 12 hours 7 to 14 days Acute Sinusitis 400 mg every 12 hours 10 days Adults with creatinine clearance 5 to 29 mL/min 250 to 500 mg q 18 h ( 2.3 ) Pediatric Intravenous Dosing Guidelines Infection Dose Frequency Duration Complicated UTI and Pyelonephritis (patients from 1 to 17 years of age) 6 mg/kg to 10 mg/kg (maximum 400 mg per dose) Every 8 hours 10 to 21 days 1 Inhalational Anthrax (Post-Exposure) 10 mg/kg (maximum 400 mg per dose) Every 12 hours 60 days Plague 10 mg/kg (maximum 400 mg per dose) Every 8 to 12 hours 14 days 2.1 Dosage in Adults The determination of dosage and duration for any particular patient must take into consideration the severity and nature of the infection, the susceptibility of the causative microorganism, the integrity of the patient's host-defense mechanisms, and the status of renal and hepatic function. Table 1: Adult Dosage Guidelines 1. Due to the designated pathogens (see Indications and Usage.) 2. Used in conjunction with metronidazole. 3. Begin administration as soon as possible after suspected or confirmed exposure. Infection 1 Dose Frequency Usual Duration Skin and Skin Structure 400 mg every 8 to 12 hours 7 to 14 days Bone and Joint 400 mg every 8 to 12 hours 4 to 8 weeks Complicated Intra-Abdominal 2 400 mg every 12 hours 7 to 14 days Nosocomial Pneumonia 400 mg every 8 hours 10 to 14 days Empirical Therapy In Febrile Neutropenic Patients Ciprofloxacin 400 mg and Piperacillin 50 mg/kg every 8 hours every 4 hours 7 to 14 days Inhalational Anthrax (Post-Exposure) 3 400 mg every 12 hours 60 days Plague 3 400 mg every 8 to 12 hours 14 days Chronic Bacterial Prostatitis 400 mg every 12 hours 28 days Lower Respiratory Tract Infections 400 mg every 8 to 12 hours 7 to 14 days Urinary Tract Infections 200 mg to 400 mg every 8 to 12 hours 7 to 14 days Acute Sinusitis 400 mg every 12 hours 10 days Conversion of Intravenous to Oral Dosing in Adults Patients whose therapy is started with ciprofloxacin injection may be switched to ciprofloxacin tablets or oral suspension when clinically indicated at the discretion of the physician ( Table 2 ) [see Clinical Pharmacology ( 12.3 )] . Table 2: Equivalent AUC Dosing Regimens Ciprofloxacin Oral Dosage Equivalent Ciprofloxacin Injection Dosage 250 mg Tablet every 12 hours 200 mg intravenous every 12 hours 500 mg Tablet every 12 hours 400 mg intravenous every 12 hours 750 mg Tablet every 12 hours 400 mg intravenous every 8 hours 2.2 Dosage in Pediatric Patients Dosing and initial route of therapy (that is, IV or oral) for cUTI or pyelonephritis should be determined by the severity of the infection. Table 3: Pediatric Dosage Guidelines 1. The total duration of therapy for cUTI and pyelonephritis in the clinical trial was determined by the physician. The mean duration of treatment was 11 days (range 10 to 21 days). 2. Begin drug administration as soon as possible after suspected or confirmed exposure. 3. Begin drug administration as soon as possible after suspected or confirmed exposure to Y. pestis . Infection Dose (mg/kg) Frequency Total Duration Complicated Urinary Tract or Pyelonephritis (patients from 1 to 17 years of age) 1 6 mg/kg to 10 mg/kg (maximum 400 mg per dose; not to be exceeded even in patients weighing more than 51 kg) Every 8 hours 10 to 21 days 1 Inhalational Anthrax (Post-Exposure) 2 10 mg/kg (maximum 400 mg per dose) Every 12 hours 60 days Plague 2,3 10 mg/kg (maximum 400 mg per dose) Every 8 to 12 hours 14 days 2.3 Dosage Modifications in Patients with Renal Impairment Ciprofloxacin is eliminated primarily by renal excretion; however, the drug is also metabolized and partially cleared through the biliary system of the liver and through the intestine. These alternative pathways of drug elimination appear to compensate for the reduced renal excretion in patients with renal impairment. Nonetheless, some modification of dosage is recommended, particularly for patients with severe renal dysfunction. Dosage guidelines for use in patients with renal impairment are shown in Table 4 . Table 4: Recommended Starting and Maintenance Doses for Adult Patients with Impaired Renal Function Creatinine Clearance (mL/min) Dose >30 See Usual Dosage. 5 to 29 200 to 400 mg every 18 to 24 hours When only the serum creatinine concentration is known, the following formulas may be used to estimate creatinine clearance: Men - Creatinine clearance (mL/min) = Weight (kg) × (140 - age) 72 × serum creatinine (mg/dL) Women - 0.85 × the value calculated for men. The serum creatinine should represent a steady state of renal function. In patients with severe infections and severe renal impairment and hepatic insufficiency, careful monitoring is suggested. Pediatric patients with moderate to severe renal insufficiency were excluded from the clinical trial of cUTI and pyelonephritis. No information is available on dosing adjustments necessary for pediatric patients with moderate to severe renal insufficiency (that is, creatinine clearance of < 50 mL/min/1.73m 2 ). 2.4 Preparation of Ciprofloxacin Injection for Administration Flexible Containers Ciprofloxacin injection is available as a 0.2% premixed solution in 5% dextrose in flexible containers of 100 mL or 200 mL. The solutions in flexible containers do not need to be diluted and may be infused as described above. Caution: After removing the overwrap check for minute leaks by squeezing the inner bag firmly. If leaks are found, discard container as sterility may be compromised. Use only if solution is clear and the container is undamaged. 2.5 Important Administration Instructions Intravenous Infusion Ciprofloxacin injection should be administered by intravenous infusion over a period of 60 minutes. Slow infusion of a dilute solution into a larger vein will minimize patient discomfort and reduce the risk of venous irritation. Hydration of Patients Receiving Ciprofloxacin Injection Adequate hydration of patients receiving ciprofloxacin injection should be maintained to prevent the formation of highly concentrated urine. Crystalluria has been reported with quinolones [see Warnings and Precautions ( 5.17 ), Adverse Reactions ( 6.1 ), Nonclinical Toxicology ( 13.2 ) and Patient Counseling Information ( 17 )].

Most frequent adverse reactions from clinical trials were: nausea (2.5%), diarrhea (1.6%), abnormal liver function tests (1.3%), vomiting (1%), and rash (1%).