Montelukast sodium, USP the active ingredient in montelukast sodium chewable tablets, is a selective and orally active leukotriene receptor antagonist that inhibits the cysteinyl leukotriene CysLT 1 receptor. Montelukast sodium, USP is described chemically as 1-[[[(1R)-1-[3-[(1E)-2-(7-Chloro-2-quinolinyl) ethenyl] phenyl]-3-[2- (1-hydroxy-1-methylethyl) phenyl] propyl] thio] methyl] cyclopropane acetic acid, sodium salt. The empirical formula is C 35 H 35 ClNNaO 3 S, and its molecular weight is 608.17. The structural formula is: Montelukast sodium, USP is a hygroscopic, optically active, white or almost white colored powder. Montelukast sodium, USP is freely soluble in water and in methylene chloride, freely soluble to very soluble in alcohol. Each 4-mg and 5-mg chewable montelukast sodium tablets contain 4.16 and 5.2 mg montelukast sodium USP, respectively, which are equivalent to 4 mg and 5 mg of montelukast, respectively. Both chewable tablets contain the following inactive ingredients: art cherry flavor, aspartame, croscarmellose sodium, ferric oxide red, hydroxypropyl cellulose, magnesium stearate, mannitol and microcrystalline cellulose. structure

Montelukast sodium chewable tablets are a leukotriene receptor antagonist indicated for: • Prophylaxis and chronic treatment of asthma in patients 2 years of age and older. • Acute prevention of exercise-induced bronchoconstriction (EIB) in patients 6 years of age and older. • Relief of symptoms of allergic rhinitis (AR): seasonal allergic rhinitis (SAR) in patients 2 years of age and older, and perennial allergic rhinitis (PAR) in patients 2 years of age and older. Reserve use for patients who have an inadequate response or intolerance to alternative therapies

Asthma Montelukast sodium chewable tablets are indicated for the prophylaxis and chronic treatment of asthma in adults and pediatric patients 2 years of age and older

Exercise-Induced Bronchoconstriction (EIB) Montelukast sodium chewable tablets are indicated for prevention of exercise-induced bronchoconstriction (EIB) in patients 6 years of age and older

Allergic Rhinitis sodium chewable tablets are indicated for the relief of symptoms of seasonal allergic rhinitis in patients 2 years of age and older and perennial allergic rhinitis in patients 2 of age and older. Because the benefits of montelukast sodium chewable tablets may not outweigh the risk of neuropsychiatric symptoms in patients with allergic rhinitis , use for patients who have an inadequate response or intolerance to alternative therapies. Montelukast sodium chewable tablets are indicated for the relief of symptoms of seasonal allergic rhinitis in patients 2 years of age and older and perennial allergic rhinitis in patients 2 years of age and older. Because the benefits of montelukast sodium chewable tablets may not outweigh the risk of neuropsychiatric symptoms in patients with allergic rhinitis , reserve use for patients who have an inadequate response or intolerance to alternative therapies.

• Montelukast Sodium Chewable Tablets 4 mg are light pink to pink colored, speckled, oval, biconvex shaped, chewable tablets debossed with 'I' on one side and '112' on the other side. • Montelukast Sodium Chewable Tablets 5 mg are light pink to pink colored, speckled, round, biconvex shaped, chewable tablets debossed with 'I' on one side and '113' on the other side. • Chewable tablets: 4 mg and 5 mg.

Administration (by indications): • Asthma: Once daily in the evening for patients 2 years and older. • Acute prevention of EIB: One tablet at least 2 hours before exercise for patients 6 years of age and older. • Seasonal allergic rhinitis: Once daily for patients 2 years and older. • Perennial allergic rhinitis: Once daily for patients 2 years and older. Dosage (by age): • 15 years and older: one 10-mg tablet. • 6 to 14 years: one 5-mg chewable tablet. • 2 to 5 years: one 4-mg chewable tablet. Patients with both asthma and allergic rhinitis should take only one dose daily in the evening

Asthma Montelukast sodium should be taken once daily in the evening. The following doses are recommended: For adults and adolescents 15 years of age and older: one 10-mg tablet. For pediatric patients 6 to 14 years of age: one 5-mg chewable tablet. For pediatric patients 2 to 5 years of age: one 4-mg chewable tablet. Safety and effectiveness in pediatric patients less than 12 months of age with asthma have not been established. who miss a dose should take the next dose at their regular time and should not take 2 doses at the same time. There have been no clinical trials in patients with asthma to evaluate the relative efficacy of morning versus evening dosing. The pharmacokinetics of montelukast are similar whether dosed in the morning or evening. Efficacy has been demonstrated for asthma when montelukast was administered in the evening without regard to time of food ingestion. Montelukast sodium should be taken once daily in the evening. The following doses are recommended: For adults and adolescents 15 years of age and older: one 10-mg tablet. For pediatric patients 6 to 14 years of age: one 5-mg chewable tablet. For pediatric patients 2 to 5 years of age: one 4-mg chewable tablet. Safety and effectiveness in pediatric patients less than 12 months of age with asthma have not been established. Patients who miss a dose should take the next dose at their regular time and should not take 2 doses at the same time. There have been no clinical trials in patients with asthma to evaluate the relative efficacy of morning versus evening dosing. The pharmacokinetics of montelukast are similar whether dosed in the morning or evening. Efficacy has been demonstrated for asthma when montelukast was administered in the evening without regard to time of food ingestion

Exercise-lnduced Bronchoconstriction (EIB) For prevention of EIB, a single dose of montelukast sodium should be taken at least 2 hours before exercise. The following doses are recommended: For adults and adolescents 15 years of age and older: one 10-mg tablet. For pediatric patients 6 to 14 years of age: one 5-mg chewable tablet. An additional dose of montelukast sodium should not be taken within 24 hours of a previous dose. Patients already taking montelukast sodium daily for another indication (including chronic asthma) should not take an additional dose to prevent EIB. All patients should have available for rescue a short-acting β-agonist. Safety and efficacy in patients younger than 6 years of age have not been established. Daily administration of montelukast sodium for the chronic treatment of asthma has not been established to prevent acute episodes of EIB

Allergic Rhinitis For allergic rhinitis, montelukast sodium should be taken once daily. Efficacy was demonstrated for seasonal allergic rhinitis when montelukast was administered in the morning or the evening without regard to time of food ingestion. The time of administration may be individualized to suit patient needs. The following doses for the treatment of symptoms of seasonal allergic rhinitis are recommended: For adults and adolescents 15 years of age and older: one 10-mg tablet. For pediatric patients 6 to 14 years of age: one 5-mg chewable tablet. For pediatric patients 2 to 5 years of age: one 4-mg chewable tablet. Safety and effectiveness in pediatric patients younger than 2 years of age with seasonal allergic rhinitis have not been established. The following doses for the treatment of symptoms of perennial allergic rhinitis are recommended: For adults and adolescents 15 years of age and older: one 10-mg tablet. For pediatric patients 6 to 14 years of age: one 5-mg chewable tablet. For pediatric patients 2 to 5 years of age: one 4-mg chewable tablet. For allergic rhinitis, montelukast sodium should be taken once daily. Efficacy was demonstrated for seasonal allergic rhinitis when montelukast was administered in the morning or the evening without regard to time of food ingestion. The time of administration may be individualized to suit patient needs. The following doses for the treatment of symptoms of seasonal allergic rhinitis are recommended: For adults and adolescents 15 years of age and older: one 10-mg tablet. For pediatric patients 6 to 14 years of age: one 5-mg chewable tablet. For pediatric patients 2 to 5 years of age: one 4-mg chewable tablet. Safety and effectiveness in pediatric patients younger than 2 years of age with seasonal allergic rhinitis have not been established. The following doses for the treatment of symptoms of perennial allergic rhinitis are recommended: For adults and adolescents 15 years of age and older: one 10-mg tablet. For pediatric patients 6 to 14 years of age: one 5-mg chewable tablet. For pediatric patients 2 to 5 years of age: one 4-mg chewable tablet. Safety and effectiveness in pediatric patients younger than 6 months of age with perennial allergic rhinitis have not been established. who miss a dose should take the next dose at their regular time and should not take 2 doses at the same time. Safety and effectiveness in pediatric patients younger than 6 months of age with perennial allergic rhinitis have not been established. Patients who miss a dose should take the next dose at their regular time and should not take 2 doses at the same time

Asthma and Allergic Rhinitis Patients with both asthma and allergic rhinitis should take only one montelukast sodium dose daily in the evening. Patients with both asthma and allergic rhinitis should take only one montelukast sodium dose daily in the evening. who miss a dose should take the next dose at their regular time and should not take 2 doses at the same time. Patients who miss a dose should take the next dose at their regular time and should not take 2 doses at the same time.

• Do not prescribe montelukast sodium to treat an acute asthma attack. • Advise patients to have appropriate rescue medication available. • Inhaled corticosteroid may be reduced gradually. Do not abruptly substitute montelukast sodium for inhaled or oral corticosteroids. • Patients with known aspirin sensitivity should continue to avoid aspirin or non-steroidal anti-inflammatory agents while taking montelukast sodium. • Systemic eosinophilia, sometimes presenting with clinical features of vasculitis consistent with Churg-Strauss syndrome, has been reported. These events have been sometimes associated with the reduction of oral corticosteroid therapy ( 5.5 and 6.2 ). • Inform patients with phenylketonuria that the 4-mg and 5-mg chewable tablets contain phenylalanine

Neuropsychiatric Events Serious neuropsychiatric (NP) events have been reported with of montelukast sodium. These postmarketing reports have been highly variable and included, but were not limited to, agitation, aggressive behavior or hostility, , depression, disorientation, disturbance in attention, dream abnormalities, dysphemia (stuttering), hallucinations, insomnia, irritability, memory impairment, -compulsive symptoms, restlessness, somnambulism, suicidal thoughts and behavior (including suicide), tic, and tremor. NP events have been reported in adult, , and pediatric patients with and without a previous history of psychiatric disorder. NP events have been reported mostly during montelukast sodium treatment, but were reported after montelukast sodium discontinuation. Animal studies showed that montelukast distributes into the brain in rats ; , the mechanisms underlying montelukast sodium-associated NP events are currently not well understood. Based upon the available data, it is difficult to identify risk for or quantify the risk of NP events with montelukast sodium use. Because of the risk NP events, the benefits of montelukast sodium may not outweigh the risks in some patients, particularly when the symptoms of disease may be mild and adequately with alternative therapies. Reserve use of montelukast sodium for patients with allergic rhinitis who have an inadequate response or intolerance to alternative . In patients with asthma or exercise-induced bronchoconstriction, consider the benefits and risks before prescribing montelukast sodium. Discuss the benefits and of montelukast sodium use with patients and caregivers when prescribing montelukast sodium. Advise patients and/or caregivers to be alert for changes in behavior or new NP symptoms when taking montelukast sodium. If changes in behavior are observed, or if new NP symptoms or suicidal thoughts and/or behavior occur, advise to discontinue montelukast sodium and contact a healthcare provider immediately. In many cases, symptoms resolved after stopping montelukast sodium therapy; , in some cases symptoms persisted after discontinuation of montelukast sodium. Therefore, continue to monitor and provide supportive care until symptoms . Re-evaluate the benefits and risks of restarting treatment with montelukast sodium if such events occur. Serious neuropsychiatric (NP) events have been reported with use of montelukast sodium. These postmarketing reports have been highly variable and included, but were not limited to, agitation, aggressive behavior or hostility, anxiousness, depression, disorientation, disturbance in attention, dream abnormalities, dysphemia (stuttering), hallucinations, insomnia, irritability, memory impairment, obsessive-compulsive symptoms, restlessness, somnambulism, suicidal thoughts and behavior (including suicide), tic, and tremor. NP events have been reported in adult, adolescent, and pediatric patients with and without a previous history of psychiatric disorder. NP events have been reported mostly during montelukast sodium treatment, but some were reported after montelukast sodium discontinuation. Animal studies showed that montelukast distributes into the brain in rats ; however, the mechanisms underlying montelukast sodium-associated NP events are currently not well understood. Based upon the available data, it is difficult to identify risk factors for or quantify the risk of NP events with montelukast sodium use. Because of the risk of NP events, the benefits of montelukast sodium may not outweigh the risks in some patients, particularly when the symptoms of disease may be mild and adequately treated with alternative therapies. Reserve use of montelukast sodium for patients with allergic rhinitis who have an inadequate response or intolerance to alternative therapies . In patients with asthma or exercise-induced bronchoconstriction, consider the benefits and risks before prescribing montelukast sodium. Discuss the benefits and risks of montelukast sodium use with patients and caregivers when prescribing montelukast sodium. Advise patients and/or caregivers to be alert for changes in behavior or for new NP symptoms when taking montelukast sodium. If changes in behavior are observed, or if new NP symptoms or suicidal thoughts and/or behavior occur, advise patients to discontinue montelukast sodium and contact a healthcare provider immediately. In many cases, symptoms resolved after stopping montelukast sodium therapy; however, in some cases symptoms persisted after discontinuation of montelukast sodium. Therefore, continue to monitor and provide supportive care until symptoms resolve. Re-evaluate the benefits and risks of restarting treatment with montelukast sodium if such events occur

Acute Asthma Montelukast sodium is not indicated for use in the reversal of bronchospasm in acute asthma attacks, including status asthmaticus. Patients should be advised to have appropriate rescue medication available. Therapy with montelukast sodium can be continued during acute exacerbations of asthma. Patients who have exacerbations of asthma after exercise should have available for rescue a short-acting inhaled β-agonist

Concomitant Corticosteroid Use While the dose of inhaled corticosteroid may be reduced gradually under medical supervision, montelukast sodium should not be abruptly substituted for inhaled or oral corticosteroids

Aspirin Sencitivity Patients with known aspirin sensitivity should continue avoidance of aspirin or non-steroidal anti-inflammatory agents while taking montelukast sodium. Although montelukast sodium is effective in improving airway function in asthmatics with documented aspirin sensitivity, it has not been shown to truncate bronchoconstrictor response to aspirin and other non-steroidal anti-inflammatory drugs in aspirin-sensitive asthmatic patients

Eosinophilic Conditions Patients with asthma on therapy with montelukast sodium may present with systemic eosinophilia, sometimes presenting with clinical features of vasculitis consistent with Churg-Strauss syndrome, a condition which is often treated with systemic corticosteroid therapy. These events have been sometimes associated with the reduction of oral corticosteroid therapy. Physicians should be alert to eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, and/or neuropathy presenting in their patients. A causal association between montelukast sodium and these underlying conditions has not been established

Phenylketonuria Phenylketonuric patients should be informed that the 4-mg and 5-mg chewable tablets contain phenylalanine (a component of aspartame), 0.672 and 0.84 mg per 4-mg and 5-mg chewable tablet, respectively.

No dose adjustment is needed when montelukast sodium is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, terfenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers .