ZILEUTON- zileuton tablet, multilayer, extended release
Natco Pharma USA LLC
HIGHLIGHTS OF PRESCRIBING INFORMATION
These highlights do not include all the information needed to use ZILEUTON EXTENDED-RELEASE TABLETS safely and effectively. See full prescribing information for ZILEUTON EXTENDED-RELEASE TABLETS.
ZILEUTON extended-release tablets, for oral use.
Initial U.S. Approval: 1996
INDICATIONS AND USAGE
DOSAGE AND ADMINISTRATION
Adults and children 12 years of age and older: The recommended dose of zileuton extended-release tablets are two 600 mg extended-release tablets twice daily, within one hour after morning and evening meals, for a total daily dose of 2400 mg. ( 2)
DOSAGE FORMS AND STRENGTHS
Extended-release tablets: 600 mg. ( 3)
WARNINGS AND PRECAUTIONS
Hepatotoxicity: Elevations of one or more hepatic function enzymes and bilirubin may occur with zileuton extended-release tablets. Assess hepatic function enzymes prior to initiation of zileuton extended-release tablets, monthly for the first 3 months, every 2-3 months for the remainder of the first year, and periodically thereafter. Use zileuton extended-release tablets with caution in patients who consume substantial quantities of alcohol and/or have a history of liver disease. ( 5.1)
Neuropsychiatric Events: Neuropsychiatric events, including sleep disorders and behavior changes, may occur with zileuton extended-release tablets. Instruct patients to be alert for neuropsychiatric events. Evaluate the risks and benefits of continuing treatment with zileuton extended-release tablets if such events occur. ( 5.2)
Most common adverse reactions (≥5%) included: sinusitis, nausea, and pharyngolaryngeal pain. ( 6.1)
To report SUSPECTED ADVERSE REACTIONS, contact DASH Pharmaceuticals LLC at 201-786-6500 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
USE IN SPECIFIC POPULATIONS
Hepatic Impairment: Zileuton extended-release tablets are contraindicated in patients with active liver disease and in patients with elevated hepatic function enzymes ≥3 times the upper limit of normal. ( 4, 5, 8.7)
See 17 for PATIENT COUNSELING INFORMATION.
FULL PRESCRIBING INFORMATION: CONTENTS*
Zileuton extended-release tablets are indicated for the prophylaxis and chronic treatment of asthma in adults and children 12 years of age and older.
Zileuton extended-release tablets are not indicated for use in the reversal of bronchospasm in acute asthma attacks. Therapy with zileuton extended-release tablets can be continued during acute exacerbations of asthma.
The recommended dosage of zileuton extended-release tablets for the treatment of patients with asthma is two 600 mg extended-release tablets twice daily, within one hour after morning and evening meals, for a total daily dose of 2400 mg. Tablets should not be chewed, cut or crushed. If a dose is missed, the patient should take the next dose at the scheduled time and not double the dose. Assess hepatic function enzymes prior to initiation of zileuton extended-release tablets and periodically during treatment [see Contraindications (4), Warnings and Precautions (5), and Use in Specific Populations (8.7)].
The use of zileuton extended-release tablets are contraindicated in patients with:
Elevations of one or more hepatic function enzymes and bilirubin may occur during zileuton extended-release tablets therapy. These laboratory abnormalities may progress to clinically significant liver injury, remain unchanged, or resolve with continued treatment, usually within three weeks. The ALT (SGPT) test is considered the most sensitive indicator of liver injury for zileuton extended-release tablets.
Assess hepatic function enzymes prior to initiation of, and during therapy with, zileuton extended-release tablets. Assess serum ALT before treatment begins, once a month for the first 3 months, every 2-3 months for the remainder of the first year, and periodically thereafter for patients receiving long-term zileuton extended-release tablets therapy. If clinical signs and/or symptoms of liver dysfunction develop (e.g., right upper quadrant pain, nausea, fatigue, lethargy, pruritus, jaundice, or "flu-like" symptoms) or transaminase elevations ≥5×ULN occur, discontinue zileuton extended-release tablets and follow hepatic function enzymes until normal.
In controlled and open-label clinical studies involving more than 5000 patients treated with zileuton immediate-release tablets, the overall rate of ALT elevation ≥3×ULN was 3.2%. In these trials, one patient developed symptomatic hepatitis with jaundice, which resolved upon discontinuation of therapy. An additional 3 patients with transaminase elevations developed mild hyperbilirubinemia that was less than 3×ULN. There was no evidence of hypersensitivity or other alternative etiologies for these findings.
Since treatment with zileuton extended-release tablets may result in increased hepatic function enzymes and liver injury, zileuton extended-release tablets should be used with caution in patients who consume substantial quantities of alcohol and/or have a past history of liver disease.
Neuropsychiatric events have been reported in adult and adolescent patients taking zileuton, the active ingredient in zileuton extended-release tablets and zileuton immediate-release tablets. Post-marketing reports with zileuton include sleep disorders and behavior changes. The clinical details of some post-marketing reports involving zileuton appear consistent with a drug-induced effect. Patients and prescribers should be alert for neuropsychiatric events. Patients should be instructed to notify their prescriber if these changes occur. Prescribers should carefully evaluate the risks and benefits of continuing treatment with zileuton extended-release tablets if such events occur [see Adverse Reactions (6.3)].
Hepatotoxicity: Elevations of one or more hepatic function enzymes and bilirubin may occur during zileuton extended-release tablets therapy [see Warnings and Precautions (5)].
The most commonly occurring adverse reactions (≥5%) with zileuton extended-release tablets are sinusitis, nausea, and pharyngolaryngeal pain.
The safety data described below reflect exposure to zileuton extended-release tablets in 199 patients for 12 weeks duration. In a 12-week, randomized, double-blind, placebo-controlled trial in adults and adolescents 12 years of age and older with asthma, patients received zileuton extended-release tablets two 600 mg tablets (n=199) or placebo (n=198) twice daily by mouth. Eighty-three percent of patients were white, 48% were male, and the mean age was 34 years.
Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.
The most commonly reported adverse reactions (occurring at a frequency of ≥5%) in zileuton extended-release tablets-treated patients and at a frequency greater than placebo-treated patients are reflected in Table 1.
Adverse Reactions with ≥5% Incidence in a 12‑Week Placebo-Controlled Trial in Patients with Asthma.
Zileuton Extended-Release Tablets
2 Tablets Twice Daily
Less common adverse reactions occurring at a frequency ≥1% and more often in the zileuton extended-release tablets group than in the placebo group included gastrointestinal disorders (upper abdominal pain, diarrhea, dyspepsia, vomiting), rash, hypersensitivity, and hepatotoxicity.
There were no differences in the incidence of adverse reactions based upon gender. The clinical trials did not include sufficient numbers of patients <18 years of age or non-Caucasians to determine whether there is any difference in adverse reactions based upon age or race.
In the 12-week placebo-controlled trial, the incidence of ALT elevations (≥3×ULN) was 2.5% (5 of 199) in the zileuton extended-release tablets group, compared to 0.5% (1 of 198) in the placebo group. In the zileuton extended-release tablets group, the majority of ALT elevations (60%) occurred in the first month of treatment, and in 2 of the 5 patients in the zileuton extended-release tablets group, ALT elevations were detected 14 days after completion of the 3-month study treatment. The levels returned to <2×ULN or normal within 9 and 12 days, respectively. The ALT elevations in the other 3 patients were observed to return to <2×ULN or normal within 15, 19, and 31 days after zileuton extended-release tablets discontinuation. There appeared to be no clinically relevant relationship between the time of onset and the magnitude of the first elevation or the magnitude of first elevation and time to resolution. The hepatic function enzyme elevations attributed to zileuton extended-release tablets did not result in any cases of jaundice, development of chronic liver disease, or death in this clinical trial.
The safety of zileuton extended-release tablets was evaluated in one 6-month, randomized, double-blind, placebo-controlled clinical trial in adults and adolescents 12 years of age and older with asthma. Patients received two 600 mg zileuton extended-release tablets (n=619) or placebo (n=307) twice daily by mouth along with usual asthma care. Eighty-six percent of patients were white, 40% were male, and the overall mean age was 36.
The rate and type of adverse reactions observed in this study were comparable to the adverse reactions observed in the 12-week study. Other commonly reported adverse reactions (occurring at a frequency of ≥5%) in zileuton extended-release tablets-treated patients and at a frequency greater than placebo-treated patients included the following: headache (23%), upper respiratory tract infection (9%), myalgia (7%), and diarrhea (5%) compared to 21%, 7%, 5% and 2%, respectively, in the placebo-treated group.
ALT elevations (≥3×ULN) were observed in 1.8% of patients treated with zileuton extended-release tablets compared to 0.7% in patients treated with placebo. The majority of elevations (82%) were reported within the first 3 months of treatment and resolved within 21 days for most of these patients after discontinuation of the drug. The hepatic function enzyme elevations attributed to zileuton extended-release tablets did not result in any cases of jaundice, development of chronic liver disease, or death in this clinical trial.
Occurrences of low white blood cell (WBC) count (<3.0 × 109/L) were observed in 2.6% (15 of 619) of the zileuton extended-release tablets treated patients and in 1.7% (5 of 307) of the placebo-treated patients. The WBC counts returned to normal or baseline following discontinuation of zileuton extended-release tablets. The clinical significance of these findings is not known.
The following adverse reactions have been identified during post-approval use of zileuton immediate-release tablets and may be applicable to zileuton extended-release tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship.
Cases of severe hepatic injury have been reported in patients taking zileuton immediate-release tablets. These cases included death, life-threatening liver injury with recovery, symptomatic jaundice, hyperbilirubinemia, and elevations of ALT >8×ULN.
Cases of sleep disorders and behavior changes have also been reported [see Warnings and Precautions (5.2)].
The following study results were obtained using zileuton immediate-release tablets but the conclusions also apply to zileuton extended-release tablets.
In a drug-interaction study in 16 healthy subjects, co-administration of multiple doses of zileuton immediate-release tablets (800 mg every 12 hours) and theophylline (200 mg every 6 hours) for 5 days resulted in a significant decrease (approximately 50%) in steady-state clearance of theophylline, an approximate doubling of theophylline AUC, and an increase in theophylline Cmax (by 73%). The elimination half-life of theophylline was increased by 24%. Also, during co-administration, theophylline-related adverse reactions were observed more frequently than after theophylline alone. Upon initiation of zileuton extended-release tablets in patients receiving theophylline, the theophylline dosage should be reduced by approximately one-half and plasma theophylline concentrations monitored. Similarly, when initiating therapy with theophylline in a patient receiving zileuton extended-release tablets, the maintenance dose and/or dosing interval of theophylline should be adjusted accordingly and guided by serum theophylline determinations.
Concomitant administration of multiple doses of zileuton immediate-release tablets (600 mg every 6 hours) and warfarin (fixed daily dose obtained by titration in each subject) to 30 healthy male subjects resulted in a 15% decrease in R-warfarin clearance and an increase in AUC of 22%. The pharmacokinetics of S-warfarin were not affected. These pharmacokinetic changes were accompanied by a clinically significant increase in prothrombin times. Monitoring of prothrombin time, or other suitable coagulation tests, with the appropriate dose titration of warfarin is recommended in patients receiving concomitant zileuton extended-release tablets and warfarin therapy.
Co-administration of zileuton immediate-release tablets and propranolol results in a significant increase in propranolol concentrations. Administration of a single 80 mg dose of propranolol in 16 healthy male subjects who received zileuton immediate-release tablets 600 mg every 6 hours for 5 days resulted in a 42% decrease in propranolol clearance. This resulted in an increase in propranolol Cmax, AUC, and elimination half-life by 52%, 104%, and 25%, respectively. There was an increase in β-blockade as shown by a decrease in heart rate associated with the co-administration of these drugs. Patients concomitantly on zileuton extended-release tablets and propranolol should be closely monitored and the dose of propranolol reduced as necessary. No formal drug-drug interaction studies between zileuton and other beta-adrenergic blocking agents (i.e., β-blockers) have been conducted. It is reasonable to employ appropriate clinical monitoring when these drugs are co-administered with zileuton extended-release tablets.
Drug-drug interaction studies conducted in healthy subjects between zileuton immediate-release tablets and prednisone and ethinyl estradiol (oral contraceptive), drugs known to be metabolized by the CYP3A4 isoenzyme, have shown no significant interaction. However, no formal drug-drug interaction studies between zileuton and CYP3A4 inhibitors, such as ketaconazole, have been conducted. It is reasonable to employ appropriate clinical monitoring when these drugs are co-administered with zileuton extended-release tablets.
Drug-drug interaction studies in healthy subjects have been conducted with zileuton immediate-release tablets and digoxin, phenytoin, sulfasalazine, and naproxen. There was no significant interaction between zileuton and any of these drugs.
Information on specific populations is based on studies conducted with zileuton immediate-release tablets and is applicable to zileuton extended-release tablets.
The safety and effectiveness of zileuton extended-release tablets in pediatric patients under 12 years of age have not been established. FDA has not required pediatric studies in patients under the age of 12 years due to the risk of hepatotoxicity. Zileuton extended-release tablets are not appropriate for children less than 12 years of age.
Subgroup analysis of controlled and open-label clinical studies with zileuton immediate-release tablets suggests that females ≥65 years of age appear to be at increased risk of ALT elevations. In zileuton extended-release tablets placebo-controlled studies there were no discernable trends in ALT elevations noted in subset analyses for patients ≥65 years of age, although the database may not have been sufficiently large to detect a trend [see Pharmacokinetics (12.3)].
Dosing adjustment in patients with renal dysfunction or patients undergoing hemodialysis is not necessary [see Pharmacokinetics (12.3)].
Human experience of acute overdose with zileuton is limited. A patient in a clinical study took between 6.6 and 9.0 grams of zileuton immediate-release tablets in a single dose. Vomiting was induced and the patient recovered without sequelae. Zileuton is not removed by dialysis. Should an overdose occur, the patient should be treated symptomatically and supportive measures instituted as required. If indicated, elimination of unabsorbed drug should be achieved by emesis or gastric lavage; usual precautions should be observed to maintain the airway. A Certified Poison Control Center should be consulted for up-to-date information on management of overdose with zileuton extended-release tablets.
Zileuton is an orally active inhibitor of 5-lipoxygenase, the enzyme that catalyzes the formation of leukotrienes from arachidonic acid. Zileuton has the chemical name (±)-1-(1-Benzo[b]thien-2-ylethyl)-1-hydroxyurea and the following chemical structure:
Zileuton has the molecular formula C 11H 12N 2O 2S and a molecular weight of 236.29. It is a racemic mixture (50:50) of R(+) and S(-) enantiomers. Zileuton is a practically odorless, white, crystalline powder that is soluble in methanol and ethanol, slightly soluble in acetonitrile, and practically insoluble in water and hexane. The melting point ranges from 144.2°C to 145.2°C.
Zileuton extended-release tablets for oral administration are bi-layer tablets comprised of an immediate-release layer and an extended-release layer. Zileuton extended-release tablets are white to off-white color, oblong shaped film coated tablets debossed with D130 on one side and plain on another side. Each tablet contains 600 mg of zileuton and the following inactive ingredients: colloidal silicon dioxide, crospovidone, hydroxypropyl cellulose, hypromellose, magnesium stearate, mannitol, microcrystalline cellulose, polyethylene glycol, pregelatinised starch, sodium lauryl sulfate, sodium starch glycolate.
Zileuton is an inhibitor of 5-lipoxygenase and thus inhibits leukotriene (LTB 4, LTC 4, LTD 4 and LTE 4) formation. Both the R(+) and S(-) enantiomers are pharmacologically active as 5-lipoxygenase inhibitors in in vitro and in vivo systems. Leukotrienes are substances that induce numerous biological effects including augmentation of neutrophil and eosinophil migration, neutrophil and monocyte aggregation, leukocyte adhesion, increased capillary permeability, and smooth muscle contraction. These effects contribute to inflammation, edema, mucus secretion, and bronchoconstriction in the airways of asthmatic patients. LTB 4, a chemoattractant for neutrophils and eosinophils, and cysteinyl leukotrienes (LTC 4, LTD 4, LTE 4) can be measured in a number of biological fluids including bronchoalveolar lavage fluid (BALF), blood, urine and sputum from asthmatic patients.
Zileuton is an orally active inhibitor of ex vivo LTB 4 formation in several species, including mice, rats, rabbits, dogs, sheep, and monkeys. Zileuton inhibits arachidonic acid-induced ear edema in mice, neutrophil migration in mice in response to polyacrylamide gel, and eosinophil migration into the lungs of antigen-challenged sheep. In a mouse model of allergic inflammation, zileuton inhibited neutrophil and eosinophil influx, reduced the levels of multiple cytokines in the BALF, and reduced serum IgE levels. Zileuton inhibits leukotriene-dependent smooth muscle contractions in vitro in guinea pig and human airways. The compound inhibits leukotriene-dependent bronchospasm in antigen and arachidonic acid-challenged guinea pigs. In antigen-challenged sheep, zileuton inhibits late-phase bronchoconstriction and airway hyperreactivity. The clinical relevance of these findings is unknown.
Zileuton is an orally active inhibitor of ex vivo LTB 4 formation in humans. The inhibition of LTB 4 formation in whole blood is directly related to zileuton plasma levels. In patients with asthma, the IC 50 is estimated to be 0.46 µg/mL, and maximum inhibition ≥80% is reached at a zileuton concentration of 2 µg/mL. In patients with asthma receiving zileuton immediate-release tablets 600 mg four times daily, peak plasma levels averaging 5.9 µg/mL were associated with a mean LTB 4 inhibition of 98%. Zileuton inhibits the synthesis of cysteinyl leukotrienes as demonstrated by reduced urinary LTE 4 levels.
Information on the pharmacokinetics of zileuton following the administration of zileuton immediate-release tablets is available in healthy subjects. The results of two clinical pharmacology studies using zileuton extended-release tablets are described below.
A three-way crossover study was conducted in healthy male and female subjects (n=23) with a mean age of 33 (range 20-55) following single dose of 1200 mg (2 × 600 mg) zileuton extended-release tablets under fasted and fed conditions, and two doses of 600 mg zileuton immediate-release tablets every 6 hours under fasted conditions. Food increased the peak mean plasma concentrations (Cmax) and the mean extent of absorption (AUC) of zileuton extended-release tablets by 18 and 34%, respectively, and prolonged Tmax from 2.1 hours to 4.3 hours. The relative bioavailability of zileuton extended-release tablets to zileuton immediate-release tablets with respect to Cmax and AUC under fasted conditions were 0.39 (90% CI: 0.36, 0.43) and 0.57 (90% CI: 0.52, 0.62), respectively. Similarly, relative bioavailability of zileuton extended-release tablets to zileuton immediate-release tablets with respect to Cmax and AUC under fed conditions were 0.45 (90% CI: 0.41, 0.49) and 0.76 (90% CI: 0.70, 0.83), respectively.
A three-way crossover study was conducted in healthy male and female subjects (n=24) with a mean age of 35 (range 19-56) following multiple doses of 1200 mg (2 × 600 mg) zileuton extended-release tablets administered every 12 hours under fasted and fed conditions, and 600 mg zileuton immediate-release tablets every 6 hours under fed conditions until steady state zileuton levels were achieved. Food increased AUC and Cmin of zileuton extended-release tablets by 43% and 170%, respectively, but had no effect on Cmax. Therefore, zileuton extended-release tablets are recommended to be administered with food [see Dosage and Administration (2)]. At steady state, relative bioavailability of zileuton extended-release tablets to zileuton immediate-release tablets with respect to Cmax, Cmin, and AUC were 0.65 (90% CI: 0.60, 0.71), 1.05 (90% CI: 0.88, 1.25) and 0.85 (90% CI: 0.78, 0.92) respectively. These data indicate that at steady state under fed conditions the Cmax of zileuton extended-release tablets is about 35% lower than that of zileuton immediate-release tablets but the Cmin and AUC are similar for both formulations.
The apparent volume of distribution (V/F) of zileuton is approximately 1.2 L/kg. Zileuton is 93% bound to plasma proteins, primarily to albumin, with minor binding to α1 acid glycoprotein.
Elimination of zileuton is predominantly via metabolism with a mean terminal half-life of 3.2 hours. Apparent oral clearance (CL/F) of zileuton is 669 mL/min. Zileuton activity is primarily due to the parent drug. Studies with radiolabeled drug have demonstrated that orally administered zileuton is well absorbed into the systemic circulation with 94.5% and 2.2% of the radiolabeled dose recovered in urine and feces, respectively.
In vitro studies utilizing human liver microsomes have shown that zileuton and its N-dehydroxylated metabolite can be oxidatively metabolized by CYP1A2, CYP2C9 and CYP3A4.
Several zileuton metabolites have been identified in human plasma and urine. These include two diastereomeric O-glucuronide conjugates (major metabolites) and an N-dehydroxylated metabolite (A-66193) of zileuton. The urinary excretion of the inactive A-66193 metabolite and unchanged zileuton each accounted for less than 0.5% of the single radiolabeled dose. Multiple doses of 1200 mg zileuton extended-release tablets twice daily resulted in peak plasma levels of 4.9 µg/mL of the inactive metabolite A-66193 with an AUC of 93 µg·hr/mL, showing large inter-subject variability. This inactive metabolite has been shown to be formed by the gastrointestinal microflora prior to the absorption of zileuton and its formation increases with delayed absorption of zileuton.
The pharmacokinetics of zileuton immediate-release tablets were similar in healthy subjects and in subjects with mild, moderate, and severe renal insufficiency. In subjects with renal failure requiring hemodialysis, zileuton pharmacokinetics were not altered by hemodialysis and a very small percentage of the administered zileuton dose (<0.5%) was removed by hemodialysis. Hence, dosing adjustment in patients with renal dysfunction or undergoing hemodialysis is not necessary.
The pharmacokinetics of zileuton immediate-release tablets were compared between subjects with mild and moderate chronic hepatic insufficiency. The mean apparent plasma clearance of total zileuton in subjects with hepatic impairment was approximately half the value of the healthy subjects. The percent binding of zileuton to plasma proteins after multiple dosing was significantly reduced in patients with moderate hepatic impairment. Zileuton extended-release tablets are contraindicated in patients with active liver disease or persistent ALT elevations ≥3×ULN [see Warnings and Precautions (5)].
The pharmacokinetics of zileuton immediate-release tablets were investigated in healthy elderly subjects (ages 65 to 81 years, 9 males, 9 females) and healthy young subjects (ages 20 to 40 years, 5 males, 4 females) after single and multiple oral doses of 600 mg zileuton every 6 hours. Zileuton pharmacokinetics were similar in healthy elderly subjects (≥65 years) compared to healthy younger adults (20 to 40 years).
In 2-year carcinogenicity studies, increases in the incidence of liver, kidney, and vascular tumors in female mice and a trend toward an increase in the incidence of liver tumors in male mice were observed at 450 mg/kg/day (providing approximately 5 times [females] or 8 times [males] the systemic exposure [AUC=64 µg·hr/mL] achieved at the MRHD). No increase in the incidence of tumors was observed at 150 mg/kg/day (providing approximately 2-3 times the systemic exposure [AUC] achieved at the MRHD). In rats, an increase in the incidence of kidney tumors was observed in both sexes at 170 mg/kg/day (providing approximately 8 times [males] or 16 times [females] the systemic exposure [AUC] achieved at the MRHD). No increased incidence of kidney tumors was seen at 80 mg/kg/day (providing approximately 4 times [males] or 7 times [females] the systemic exposure [AUC] achieved at the MRHD). Although a dose-related increased incidence of benign Leydig cell tumors was observed, Leydig cell tumorigenesis was prevented by supplementing male rats with testosterone.
Zileuton was negative in genotoxicity studies including bacterial reverse mutation (Ames) using S. typhimurium and E. coli, chromosome aberration in human lymphocytes, in vitro unscheduled DNA synthesis (UDS), in rat hepatocytes with or without zileuton pretreatment and in mouse and rat kidney cells with zileuton pretreatment, and mouse micronucleus assays. However, a dose-related increase in DNA adduct formation was reported in kidneys and livers of female mice treated with zileuton. Although some evidence of DNA damage was observed in a UDS assay in hepatocytes isolated from Aroclor-254-treated rats, no such finding was noticed in hepatocytes isolated from monkeys, where the metabolic profile of zileuton is more similar to that of humans.
In reproductive performance/fertility studies, zileuton produced no effects on fertility in rats at oral doses up to 300 mg/kg/day (providing at least 10 times [male rats] and greater than 20 times [female rats] the systemic exposure [AUC] achieved at the MRHD). However, reduction in fetal implants was observed at oral doses of 150 mg/kg/day and higher (providing approximately 20 times the systemic exposure [AUC] achieved at the MRHD). Comparative systemic exposure (AUC) is based on measurements in male rats or nonpregnant female rats obtained from the comparable doses of 3-month or 1-year general toxicity study at similar dosages. Increases in gestation length, prolongation of estrus cycle, and increases in stillbirths were observed at oral doses of 75 mg/kg/day and higher (providing approximately 7 times the systemic exposure [AUC] achieved at the MRHD on an AUC basis with data obtained from the comparable doses of 2-year dietary carcinogenicity study). No adverse effects were observed at 15 mg/kg/day in the study at estimated exposure similar to that at the MRHD.
The efficacy of zileuton extended-release tablets was evaluated in a randomized, double-blind, parallel-group, placebo-controlled, multicenter trial of 12 weeks duration in patients 12 years of age and older with asthma. The 12-week trial included 199 patients randomized to zileuton extended-release tablets (two 600 mg tablets twice daily) and 198 to placebo. Eighty-three percent of patients were white, 48% were male, and the mean age was 34 years. The mean baseline FEV1 percent predicted was 58.5%.
Assessment of efficacy was based upon forced expiratory volume in one second (FEV 1) at 12 weeks. Zileuton extended-release tablets demonstrated a significantly greater improvement in mean change from baseline trough FEV 1 at 12 weeks compared to placebo (0.39 L vs. 0.27 L; p=0.021). The mean change from baseline FEV 1 over the course of the 12-week study is shown in Figure 1. Secondary endpoints (PEFR and rescue beta-agonist use) were supportive of efficacy.
Examination of gender subgroups did not identify differences in response between men and women. The database was not large enough to assess whether there were differences in response in age or racial subgroups.
Mean Change from Baseline in Trough FEV 1 in
12-Week Clinical Trial in Patients with Asthma.
*p ≤0.050. Endpoint analysis based on last-observation-carried-forward (LOCF) methodology.
Zileuton extended-release white to off-white color oblong shaped film coated tablets are debossed with D130 on one side and plain on another side; they are available in bottles of 120 tablets with child-resistant closure. (NDC 69339-130-12).
Patients should be told that:
Zileuton (zye LOO ton) extended-release tablets
Read the Patient Information that comes with zileuton extended-release tablets carefully before you start taking it and read it each time you get a refill. There may be new information. This leaflet does not take the place of talking with your health care provider about your medical condition or your treatment.
What are zileuton extended-release tablets?
Zileuton extended-release tablets are the medicine that are used to prevent asthma attacks and for long-term management of asthma in adults and children 12 years of age and older. Zileuton extended-release tablets blocks the production of leukotrienes. Leukotrienes are substances that may contribute to your asthma.
Zileuton extended-release tablets are not the rescue medicine (that are not the bronchodilators) and should not be used if you need relief right away for an asthma attack.
Who should not take zileuton extended-release tablets?
Do not take zileuton extended-release tablets if you have:
What should I tell my health care provider before taking zileuton extended-release tablets?
Zileuton extended-release tablets may not be right for you. Tell your health care provider if you:
Tell your health care provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Zileuton extended-release tablets and other medicines may affect each other causing side effects. Your health care provider may need to adjust the doses of certain medicines while you are taking zileuton extended-release tablets. Talk with your health care provider before starting or stopping any prescription or nonprescription medicine.
Know the medicines you take. Keep a list of your medicines and show it to your health care provider and pharmacist when you get a new medicine.
How should I take zileuton extended-release tablets?
What are the possible side effects of zileuton extended-release tablets?
Zileuton extended-release tablets can cause serious side effects.
Liver problems.Liver function enzymes and bilirubin can increase while taking zileuton extended-release tablets, and severe liver injury can occur.
Sleep disorders and changes in your behavior can happen while you take zileuton extended-release tablets. Tell your healthcare provider if you have any sleep problems or changes in behavior.
Some of the most common side effects are:
Allergic reactions can happen while taking zileuton extended-release tablets. Tell your health care provider right away if you get any of the following signs or symptoms: rash or hives.
Tell your health care provider if you have any new or unusual symptoms that bother you or do not go away while taking zileuton extended-release tablets.
These are not all of the possible side effects of zileuton extended-release tablets. For more information, ask your health care provider or pharmacist.
How should I store zileuton extended-release tablets?
Keep zileuton extended-release tablets and all medicines out of the reach of children.
General Information about zileuton extended-release tablets:
Medicines are sometimes prescribed for conditions that are not mentioned in the patient leaflet. Do not use zileuton extended-release tablets for a condition for which it was not prescribed. Do not give zileuton extended-release tablets to other people, even if they have the same symptoms you have. It may harm them.
This patient information leaflet summarizes the most important information about zileuton extended-release tablets. If you would like more information about zileuton extended-release tablets, talk with your health care provider or pharmacist. You can ask your health care provider or pharmacist for information about zileuton extended-release tablets that is written for health professionals.
For more information, call 201-786-6500.
What are the ingredients in zileuton extended-release tablets?
Active ingredient: zileuton
Inactive ingredients: colloidal silicon dioxide, crospovidone, hydroxypropyl cellulose, hypromellose, magnesium stearate, mannitol, microcrystalline cellulose, polyethylene glycol, pregelatinised starch, sodium lauryl sulfate, sodium starch glycolate.
Aizant Drug Research Solutions Pvt. Ltd.,
DASH Pharmaceuticals LLC,
Upper Saddle River, NJ 07458, USA.
zileuton tablet, multilayer, extended release
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