Ciprofloxacin (Page 8 of 11)

8.5 Geriatric Use

Geriatric patients are at increased risk for developing severe tendon disorders including tendon rupture when being treated with a fluoroquinolone such as ciprofloxacin. This risk is further increased in patients receiving concomitant corticosteroid therapy. Tendinitis or tendon rupture can involve the Achilles, hand, shoulder, or other tendon sites and can occur during or after completion of therapy; cases occurring up to several months after fluoroquinolone treatment have been reported. Caution should be used when prescribing ciprofloxacin to elderly patients especially those on corticosteroids. Patients should be informed of this potential adverse reaction and advised to discontinue ciprofloxacin and contact their healthcare provider if any symptoms of tendinitis or tendon rupture occur [see Boxed Warning, Warnings and Precautions (5.2), and Adverse Reactions (6.2)].

Epidemiologic studies report an increased rate of aortic aneurysm and dissection within two months following use of fluoroquinolones, particularly in elderly patients [see Warnings and Precautions (5.9)].

In a retrospective analysis of 23 multiple-dose controlled clinical trials of ciprofloxacin encompassing over 3500 ciprofloxacin-treated patients, 25% of patients were greater than or equal to 65 years of age and 10% were greater than or equal to 75 years of age. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals on any drug therapy cannot be ruled out. Ciprofloxacin is known to be substantially excreted by the kidney, and the risk of adverse reactions may be greater in patients with impaired renal function. No alteration of dosage is necessary for patients greater than 65 years of age with normal renal function. However, since some older individuals experience reduced renal function by virtue of their advanced age, care should be taken in dose selection for elderly patients, and renal function monitoring may be useful in these patients [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3)].

In general, elderly patients may be more susceptible to drug-associated effects on the QT interval. Therefore, precaution should be taken when using ciprofloxacin with concomitant drugs that can result in prolongation of the QT interval (for example, class IA or class III antiarrhythmics) or in patients with risk factors for torsade de pointes (for example, known QT prolongation, uncorrected hypokalemia) [see Warnings and Precautions (5.12)].

8.6 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 [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3)].

8.7 Hepatic Impairment

In preliminary studies in patients with stable chronic liver cirrhosis, no significant changes in ciprofloxacin pharmacokinetics have been observed. The pharmacokinetics of ciprofloxacin in patients with acute hepatic insufficiency, have not been studied.

10 OVERDOSAGE

In the event of acute overdosage, reversible renal toxicity has been reported in some cases. Observe the patient carefully and give supportive treatment, including monitoring of renal function, urinary pH and acidify, if required, to prevent crystalluria. Adequate hydration must be maintained. Only a small amount of ciprofloxacin (less than 10%) is removed from the body after hemodialysis or peritoneal dialysis.

In mice, rats, rabbits and dogs, significant toxicity including tonic/clonic convulsions was observed at intravenous doses of ciprofloxacin between 125 mg/kg and 300 mg/kg.

11 DESCRIPTION

Ciprofloxacin Injection, USP (in 5% Dextrose Injection) is a synthetic antimicrobial agent for intravenous (IV) administration. Ciprofloxacin, a fluoroquinolone, is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid. Its empirical formula is C17 H18 FN3 O3 and its chemical structure is:

Chemical Structure
(click image for full-size original)

Ciprofloxacin is a faint to light yellow crystalline powder with a molecular weight of 331.4. It is soluble in dilute (0.1N) hydrochloric acid and is practically insoluble in water and ethanol. Ciprofloxacin Injection, USP solution is a sterile 0.2% ready-for-use infusion solution in 5% Dextrose Injection. The formula contains lactic acid as a solubilizing agent and hydrochloric acid for pH adjustment. The pH range for the 0.2% ready-for-use infusion solutions is 3.5 to 4.6.

The plastic container is not made with natural rubber latex and is fabricated from a specially formulated polyvinyl chloride. Solutions in contact with the plastic container can leach out certain of its chemical components in very small amounts within the expiration period, for example, Cyclohexanone and Chlorobenzene, up to 115 and 0.09 parts per million, respectively. The suitability of the plastic has been confirmed in tests in animals according to USP biological tests for plastic containers as well as by tissue culture toxicity studies.

The glucose content for the 100 mL bag is 5 g and 10 g for the 200 mL flexible container.

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Ciprofloxacin is a member of the fluoroquinolone class of antibacterial agents [see Microbiology (12.4)].

12.3 Pharmacokinetics

Absorption

Following 60-minute intravenous infusions of 200 mg and 400 mg ciprofloxacin to normal volunteers, the mean maximum serum concentrations achieved were 2.1 and 4.6 mcg/mL, respectively; the concentrations at 12 hours were 0.1 and 0.2 mcg/mL, respectively (Table 9).

Table 9: Steady-state Ciprofloxacin Serum Concentrations (mcg/mL) After 60-minute INTRAVENOUS Infusions every 12 hours.
Time after starting the infusion
Dose 30 minutes 1 hour 3 hour 6 hour 8 hour 12 hour
200 mg 1.7 2.1 0.6 0.3 0.2 0.1
400 mg 3.7 4.6 1.3 0.7 0.5 0.2

The pharmacokinetics of ciprofloxacin are linear over the dose range of 200 mg to 400 mg administered intravenously. Comparison of the pharmacokinetic parameters following the 1st and 5th intravenous dose on an every 12 hour regimen indicates no evidence of drug accumulation.

The absolute bioavailability of oral ciprofloxacin is within a range of 70 to 80% with no substantial loss by first pass metabolism. An intravenous infusion of 400-mg ciprofloxacin given over 60 minutes every 12 hours has been shown to produce an area under the serum concentration time curve (AUC) equivalent to that produced by a 500-mg oral dose given every 12 hours. An intravenous infusion of 400 mg ciprofloxacin given over 60 minutes every 8 hours has been shown to produce an AUC at steady-state equivalent to that produced by a 750-mg oral dose given every 12 hours. A 400-mg intravenous dose results in a Cmax similar to that observed with a 750-mg oral dose (Table 10). An infusion of 200 mg ciprofloxacin given every 12 hours produces an AUC equivalent to that produced by a 250-mg oral dose given every 12 hours.

Table 10: Steady–state Pharmacokinetic Parameters Following Multiple Oral and Intravenous Doses (adults)

* AUC 0-12h x 2

** AUC 0-8h x 3

Parameters 500 mg 400 mg 750 mg 400 mg
every 12 hours, orally every 12 hours, intravenously every 12 hours, orally every 8 hours,intravenously
AUC (0-24h),ss (mcg•h/mL) 27.4* 25.4* 31.6* 32.9**
Cmax,ss (mcg/mL) 2.97 4.56 3.59 4.07

Distribution

After intravenous administration, ciprofloxacin is widely distributed throughout the body. Tissue concentrations often exceed serum concentrations in both men and women, particularly in genital tissue including the prostate. Ciprofloxacin is present in active form in the saliva, nasal and bronchial secretions, mucosa of the sinuses, sputum, skin blister fluid, lymph, peritoneal fluid, bile, and prostatic secretions. Ciprofloxacin has also been detected in lung, skin, fat, muscle, cartilage, and bone. The drug diffuses into the cerebrospinal fluid (CSF); however, CSF concentrations are generally less than 10% of peak serum concentrations. Low levels of the drug have been detected in the aqueous and vitreous humors of the eye.

Metabolism

After intravenous administration, three metabolites of ciprofloxacin have been identified in human urine which together account for approximately 10% of the intravenous dose. The metabolites have antimicrobial activity, but are less active than unchanged. 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 [see Contraindications (4.2), Warnings and Precautions (5.10, 5.16) and Drug Interactions (7)].

Excretion

The serum elimination half-life is approximately 5 to 6 hours and the total clearance is around 35 L/hr. After intravenous administration, approximately 50% to 70% of the dose is excreted in the urine as unchanged drug. Following a 200-mg intravenous dose, concentrations in the urine usually exceed 200 mcg/mL 0 to 2 hours after dosing and are generally greater than 15 mcg/mL 8 to 12 hours after dosing. Following a 400 mg intravenous dose, urine concentrations generally exceed 400 mcg/mL 0 to 2 hours after dosing and are usually greater than 30 mcg/mL 8 to 12 hours after dosing. The renal clearance is approximately 22 L/hr. The urinary excretion of ciprofloxacin is virtually complete by 24 hours after dosing.

Although bile concentrations of ciprofloxacin are several fold higher than serum concentrations after intravenous dosing, only a small amount of the administered dose (less than 1%) is recovered from the bile as unchanged drug. Approximately 15% of an intravenous dose is recovered from the feces within 5 days after dosing.

Specific Populations

Elderly

Pharmacokinetic studies of the oral (single dose) and intravenous (single and multiple dose) forms of ciprofloxacin indicate that plasma concentrations of ciprofloxacin are higher in elderly subjects (older than 65 years) as compared to young adults. Although the Cmax is increased 16% to 40%, the increase in mean AUC is approximately 30%, and can be at least partially attributed to decreased renal clearance in the elderly. Elimination half-life is only slightly (~20%) prolonged in the elderly. These differences are not considered clinically significant [see Use in Specific Populations (8.5)].

Renal Impairment

In patients with reduced renal function, the half-life of ciprofloxacin is slightly prolonged. Dosage adjustments may be required [see Use in Specific Populations (8.6) and Dosage and Administration (2.3)].

Hepatic Impairment

In preliminary studies in patients with stable chronic liver cirrhosis, no significant changes in ciprofloxacin pharmacokinetics have been observed. The kinetics of ciprofloxacin in patients with acute hepatic insufficiency, have not been fully studied.

Pediatrics

Table 11 summarizes pharmacokinetic parameters in pediatric patients aged less than 1 to less than 12 years of age receiving intravenous treatment.

Table 11: Estimated AUC0–24,ss and Cmax,ss for Intravenous Treatment (1-h infusion) in Pediatric Patients following a Multiple Dosing Regimen of 10 mg/kg, Three Times Daily

* 3 x AUC0-8,ss

Age AUC 0-24,ss (mg•h/L) C max,ss (mg/L)
Less than 1 year 30.9* 2.8*
1 to less than 2 years 27.8* 3.6*
2 to less than 6 years 28.9* 2.7*
6 to less than 12 years 20.4* 2.0*

These values are within the range reported for adults at therapeutic doses. Based on population pharmacokinetic analysis of pediatric patients with various infections, the predicted mean half-life in children is approximately 4 hours to 5 hours, and the bioavailability of the oral suspension is approximately 60%.

Drug-Drug Interactions

Metronidazole

The serum concentrations of ciprofloxacin and metronidazole were not altered when these two drugs were given concomitantly.

Tizanidine

In a pharmacokinetic study, systemic exposure of tizanidine (4 mg single dose) was significantly increased (Cmax 7-fold, AUC 10-fold) when the drug was given concomitantly with ciprofloxacin (500 mg twice a day for 3 days). Concomitant administration of tizanidine and ciprofloxacin is contraindicated due to the potentiation of hypotensive and sedative effects of tizanidine [see Contraindications (4.2)].

Ropinirole

In a study conducted in 12 patients with Parkinson’s disease who were administered 6 mg ropinirole once daily with 500 mg ciprofloxacin twice-daily, the mean Cmax and mean AUC of ropinirole were increased by 60% and 84%, respectively. 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

Following concomitant administration of 250 mg ciprofloxacin with 304 mg clozapine for 7 days, serum concentrations of clozapine and N-desmethylclozapine were increased by 29% and 31%, respectively. Careful monitoring of clozapine associated adverse reactions and appropriate adjustment of clozapine dosage during and shortly after co-administration with ciprofloxacin are advised.

Sildenafil

Following concomitant administration of a single oral dose of 50 mg sildenafil with 500 mg ciprofloxacin to healthy subjects, the mean Cmax and mean AUC of sildenafil were both increased approximately two-fold. Use sildenafil with caution when co-administered with ciprofloxacin due to the expected two-fold increase in the exposure of sildenafil upon co-administration of ciprofloxacin.

Duloxetine

In clinical studies it was demonstrated that concomitant use of duloxetine with strong inhibitors of the CYP450 1A2 isozyme such as fluvoxamine, may result in a 5-fold increase in mean AUC and a 2.5-fold increase in mean Cmax of duloxetine.

Lidocaine

In a study conducted in 9 healthy volunteers, concomitant use of 1.5 mg/kg IV lidocaine with 500 mg ciprofloxacin twice daily resulted in an increase of lidocaine Cmax and AUC by 12% and 26%, respectively. Although lidocaine treatment was well tolerated at this elevated exposure, a possible interaction with ciprofloxacin and an increase in adverse reactions related to lidocaine may occur upon concomitant administration.

All MedLibrary.org resources are included in as near-original form as possible, meaning that the information from the original provider has been rendered here with only typographical or stylistic modifications and not with any substantive alterations of content, meaning or intent.

This site is provided for educational and informational purposes only, in accordance with our Terms of Use, and is not intended as a substitute for the advice of a medical doctor, nurse, nurse practitioner or other qualified health professional.

Privacy Policy | Copyright © 2021. All Rights Reserved.