Montelukast Sodium

Class: Leukotriene Modifiers
VA Class: RE109
Chemical Name: [R - (E)] - 1 - [[[1 - [3 - [2 - (7 - chloro - 2 - quinolinyl)ethenyl]phenyl] - 3 - [2 - (7 - chloro - 2 - quinolinyl)ethenyl]phenyl] - 3 - [2 - (1 - hydroxy - 1 - methylethyl)phenyl]propyl]thio]methyl cyclopropane acetic acid sodium
Molecular Formula: C₃₅H₃₅ClNNaO₃S
CAS Number: 151767-02-1
Brands: Singulair

Introduction

Antiasthmatic agent; leukotriene modifier.^{1 2 3 4 5 6 7 8 9 10 11 12 13 14 30 31 44 45 53 54 71 105} Pharmacologically but not structurally related to zafirlukast.^{2 71}

Uses for Montelukast Sodium

Asthma

Prevention and long-term symptomatic management of asthma.^{1 31 40 43 45 51 53 54 55 56 57 58 59 60 69 70 105 108 109 119} Efficacy for this indication demonstrated when the drug was administered in the evening.^{1 31 45}

In patients with mild persistent asthma, low-dose orally inhaled corticosteroids considered first-line agents for long-term control.^{21 38 44 45 47 70 80 86 92 105 108 110 119} Alternative agents, including certain leukotriene modifiers (i.e., montelukast, zafirlukast), may be used^{38 44 70 80 86 87 88 91 98 99 105 108 110} but are less effective than inhaled corticosteroids³⁸ and are not preferred as initial therapy.^{108 110 119 121}

In patients with moderate persistent asthma, low-dose inhaled corticosteroids with a long-acting inhaled β₂-agonist bronchodilator (e.g., salmeterol, formoterol) or monotherapy with medium-dose inhaled corticosteroids is preferred for long-term control.^{38 108 110 119} However, consider use of long-acting inhaled β₂-agonists only as additional therapy in patients whose asthma is inadequately controlled with other asthma controller drugs or whose disease severity warrants treatment with 2 maintenance therapies.^{114 115 116 117 118 122 123 124}

Alternative agents, including certain leukotriene modifiers (i.e., montelukast, zafirlukast), can be added to a low dosage of inhaled corticosteroid for treatment of moderate persistent asthma, but these options are less effective.^{110 119} Considerations favoring combination with orally inhaled corticosteroids include intolerance to long-acting β₂-adrenergic agonists, marked preference for oral therapy, and demonstration of superior responsiveness to these leukotriene modifiers.^{38 108 119}

In adults and children ≥5 years of age with severe persistent asthma, maintenance therapy with inhaled corticosteroids at medium to high dosages and a long-acting inhaled β₂-agonist preferred.^{110 119} Alternatives to a long-acting inhaled β₂-agonist in such patients receiving medium-dose inhaled corticosteroids include certain leukotriene modifiers (i.e., montelukast, zafirlukast), but are generally not preferred.^{110 119} In infants and children ≤4 years of age, an inhaled corticosteroid at medium or high dosages and either a long-acting inhaled β₂-agonist or montelukast is the only preferred treatment.¹¹⁹

Maintenance therapy with montelukast may be considered in patients who are unable or unwilling to comply with therapy using inhaled corticosteroids (e.g., young children).¹¹⁹

Not recommended for relief of acute bronchospasm; however, may continue therapy during acute asthma exacerbations.^{1 53} (See Acute Asthma under Cautions.)

Exercise-induced Bronchospasm

Prevention of exercise-induced bronchospasm.^{1 48 49 50 52}

Leukotriene modifiers not included as first-line agents or as alternative agents to orally inhaled β₂-adrenergic agonists in current guidelines;^{22 70 92 110 119} addition of montelukast may provide additional measure of control in patients currently maintained on long-term controller therapy.^{88 98 99}

Manufacturer states that patients who experience exacerbations of asthma after exercise should have a short-acting orally inhaled β₂-adrenergic agonist available for rescue.^{1 98} Not established that daily administration of montelukast for chronic treatment of asthma prevents acute episodes of exercise-induced bronchospasm.¹

Allergic Rhinitis

Symptomatic management of seasonal or perennial allergic rhinitis.^{1 87 93 111} Efficacy for this indication demonstrated when the drug was administered in the morning or evening.¹

Urticaria

Has been used successfully in patients with chronic idiopathic urticaria†; beneficial when added to existing therapy.⁸³

Montelukast Sodium Dosage and Administration

Administration

Oral Administration

Administer at regular intervals (once daily) without regard to meals.^{1 31 45}

Administer in the evening in patients with asthma with or without coexisting allergic rhinitis.^{1 31 45}

May individualize time of administration in patients with allergic rhinitis; administer at the same time each day.^{1 125}

Administer ≥2 hours before exercise in patients with exercise-induced bronchospasm; do not take an additional dose within 24 hours of previous dose.^{1 125}

Oral Granules

Generally used in children 12 months to 5 years of age.¹ Do not open packet until ready to use; administer full dose within 15 minutes of opening packet and without regard to meals.^{1 125}

Administer directly in the mouth alone or mix with a teaspoonful (5 mL) of cold or room temperature baby formula, breast milk, or soft food (i.e., applesauce, carrots, rice, ice cream).¹ Granules are not intended to be dissolved in liquid other than baby formula or breast milk prior to administration; however, liquids can be taken after administration of the granules.^{1 125} (See Stability.)

Do not store granules mixed with food for future use; discard any unused portion.^{1 125}

Dosage

Available as montelukast sodium; dosage expressed in terms of montelukast.¹

Pediatric Patients

Asthma With or Without Allergic Rhinitis

Oral

Children 12–23 months: 4 mg once daily as oral granules.¹

Children 2–5 years of age: 4 mg once daily as chewable tablets or oral granules.^{1 109}

Children 6–14 years of age: 5 mg once daily as chewable tablets.¹

Adolescents ≥15 years of age: 10 mg once daily as film-coated tablets.^{1 45}

Additional dosage not needed for treatment of allergic rhinitis in patients already receiving chronic therapy for asthma.¹

Exercise-induced Bronchospasm

Prevention

Oral

Children 6–14 years of age: 5 mg daily has been used for prevention of exercise-induced bronchospasm†.^{1 48 49 50 52 77 78}

Adolescents ≥15 years of age: 10 mg once daily as film-coated tablets.^{1 48 49 50 52 77 78}

Seasonal Allergic Rhinitis With or Without Asthma

Oral

Children 2–5 years of age: 4 mg once daily as chewable tablets or oral granules.¹

Children 6–14 years of age: 5 mg once daily as chewable tablets.¹

Adolescents ≥15 years of age: 10 mg once daily as film-coated tablets.¹

Perennial Allergic Rhinitis With or Without Asthma

Oral

Infants 6–23 months of age: 4 mg once daily as oral granules.¹

Children 2–5 years of age: 4 mg once daily as chewable tablets or oral granules.¹

Children 6–14 years of age: 5 mg once daily as chewable tablets.¹

Adolescents ≥15 years of age: 10 mg once daily as film-coated tablets.¹

Adults

Asthma With or Without Allergic Rhinitis

Oral

10 mg once daily as film-coated tablets.¹

Additional dosage not needed for treatment of allergic rhinitis in patients already receiving chronic therapy for asthma.¹

Exercise-induced Bronchospasm

Prevention

Oral

10 mg as film-coated tablets.^{1 48 49 50 52 77 78}

Seasonal Allergic Rhinitis With or Without Asthma

Oral

10 mg once daily as film-coated tablets.¹

Perennial Allergic Rhinitis With or Without Asthma

Oral

10 mg once daily as film-coated tablets.¹

Urticaria†

Oral

5–20 mg daily.⁸³

Special Populations

Hepatic Impairment

No dosage adjustment required in patients with mild to moderate hepatic impairment.¹ Not evaluated in patients with severe hepatic impairment or hepatitis.¹

Renal Impairment

No dosage adjustment required.¹

Geriatric Patients

No dosage adjustment required.¹

Cautions for Montelukast Sodium

Contraindications

• 
  

  Known hypersensitivity to montelukast or any ingredient in the formulation.¹

  
  

Warnings/Precautions

Sensitivity Reactions

Hypersensitivity Reactions

Hypersensitivity reactions, including anaphylaxis, angioedema, pruritus, urticaria, and, rarely, hepatic eosinophilic infiltration, reported.¹

Eosinophilia and Churg-Strauss Syndrome

Systemic eosinophilia, sometimes presenting with clinical features of vasculitis consistent with Churg-Strauss syndrome, reported rarely in patients receiving leukotriene modifiers;^{1 33 39 61 62 63 64 65 66 67 72 85 96} in almost all cases, these events were associated with reduction (tapered dosage) or withdrawal of oral or high-dose inhaled corticosteroid therapy.^{1 33 39 61 62 63 64 65 66 67 72 96}

Be alert to the development of eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, and/or neuropathy;^{1 31 39 72 96} causal relationship not established.^{1 31 33 39 61 62 63 64 65 66 67 72 96} Advise patients to report symptoms (i.e., feeling of pins and needles, numbness of extremities, flu-like symptoms, rash, sinusitis) immediately to their clinician.¹²⁵

General Precautions

Acute Asthma

Do not use for the relief of acute bronchospasm (including status asthmaticus); montelukast can be continued during acute exacerbations of asthma, but it will not provide immediate symptomatic relief.¹

Concomitant Corticosteroid Therapy

Do not abruptly substitute montelukast for oral or inhaled corticosteroids.¹ Orally inhaled corticosteroid requirements may be reduced during montelukast therapy; undertake only gradual (e.g., at 2-week intervals) reduction of corticosteroid dosage.^{1 40 98 99}

Exercise-induced Bronchospasm

Do not use as monotherapy for prevention of exercise-induced bronchospasm; patients who experience exacerbations of asthma after exercise should continue their usual regimen of inhaled β₂-adrenergic agonist for prophylaxis and have a short-acting orally inhaled β₂-adrenergic agonist available for rescue.¹

Aspirin Sensitivity

Patients in whom asthma is precipitated by aspirin or other NSAIAs should continue to avoid aspirin and NSAIAs.^{1 81} Montelukast can improve airway function in asthmatic patients with aspirin sensitivity; however, the drug has not been shown to truncate the bronchoconstrictor response to aspirin or other NSAIAs.¹

Phenylketonuria

Montelukast chewable tablets contain aspartame (NutraSweet), which is metabolized in the GI tract to provide 0.674 mg of phenylalanine per 4-mg chewable tablet or 0.842 mg of phenylalanine per 5-mg chewable tablet.^{1 125}

Neuropsychiatric Effects

Neuropsychiatric events reported with montelukast during postmarketing experience.^{120 125 126 127} Data from placebo-controlled trials with leukotriene modifiers indicate that suicidal ideation occurred in 0.01% of 9929 patients treated with montelukast and in none of those receiving other leukotriene modifiers; no completed suicide occurred during therapy with any leukotriene modifier.¹²⁶ FDA concluded that some neuropsychiatric events reported with montelukast (e.g., agitation, aggressive behavior or hostility, anxiousness, depression, dream abnormalities, hallucinations, insomnia, irritability, somnambulism, restlessness, tremor) appear consistent with a drug-induced effect.^{1 127}

Be alert to the potential for neuropsychiatric events in patients receiving the drug.^{1 125 127} Instruct patients to contact their clinician if behavior or mood changes occur.^{1 125 127} Carefully evaluate the risks and benefits of continuing montelukast therapy in patients who develop neuropsychiatric symptoms.^{1 127}

Specific Populations

Pregnancy

Category B.¹

Pregnancy registry at 800-986-8999.¹ ACOG generally recommends use of leukotriene receptor antagonists (i.e., montelukast, zafirlukast) as alternatives to a long-acting β₂-agonist in pregnant women with moderate persistent asthma who are inadequately controlled with low to medium dosages of an inhaled corticosteroid.¹⁰⁷ (See Asthma under Uses.)

Lactation

Distributed into milk in rats; not known whether distributed into human milk.¹ Use with caution.¹

Pediatric Use

Safety and efficacy for treatment of asthma in infants <12 months of age not established.^{1 31} Safety and efficacy for prevention of exercise-induced bronchospasm in children and adolescents <15 years of age not established.¹ Safety demonstrated in infants and children 12 months to 5 years of age with asthma; efficacy extrapolated from demonstrated efficacy in children ≥6 years of age based on similar pharmacokinetic data (systemic exposure), the similarity of the disease course, pathophysiology, and effects of the drug among these populations.^{1 85} Efficacy also supported by exploratory efficacy assessments from pediatric safety studies.^{1 109}

Safety and efficacy in infants <6 months of age with perennial allergic rhinitis not established.¹ Safety and efficacy in infants <2 years of age with seasonal allergic rhinitis not established.¹ Efficacy in children 2–14 years of age or 6 months to 14 years of age with seasonal or perennial allergic rhinitis, respectively, extrapolated from demonstrated efficacy in adolescents ≥15 years of age and the similarity of the disease course, pathophysiology, and effects of the drug among these populations.¹ Safety in pediatric patients 2–14 years of age with allergic rhinitis supported by data from studies in children from this age group with asthma.¹ Safety in infants 6–23 months of age with perennial allergic rhinitis supported by data from studies in infants with asthma and by pharmacokinetic data comparing systemic exposure in such pediatric patients with that in adults.¹

No effect of long-term therapy (56 weeks) on growth rate in pediatric patients (6–8 years of age) with mild asthma.^{1 112}

Geriatric Use

No substantial differences in safety and efficacy relative to younger adults; however, increased sensitivity in some older patients cannot be ruled out.¹

Hepatic Impairment

Exposure to montelukast may be increased.¹ (See Special Populations under Pharmacokinetics and see Special Populations under Dosage and Administration.)

Common Adverse Effects

Headache, influenza, abdominal pain, cough.^{1 125}

Interactions for Montelukast Sodium

Metabolized by CYP3A4 and CYP2C9.^{1 12}

Does not inhibit CYP3A4, 2C9, 1A2, 2A6, 2C19, or 2D6.¹ Inhibits CYP2C8 in vitro; ¹ does not inhibit CYP2C8 in vivo.^{1 113}

Drugs Affecting Hepatic Microsomal Enzymes

CYP3A4 or CYP2C9 inducers: Potential pharmacokinetic interaction (decreased plasma concentrations of montelukast).¹

CYP3A4 or CYP2C9 inhibitors: Potential pharmacokinetic interaction (increased plasma concentrations of montelukast).¹

Specific Drugs

Drug	Interaction	Comments
Benzodiazepines	No increase in adverse effects noted1
Contraceptives, oral (fixed combination of ethinyl estradiol-norethindrone)	No alteration in contraceptive pharmacokinetics1 104
Corticosteroids (prednisone, prednisolone)	No clinically important effects on corticosteroid pharmacokinetics1
Decongestants	No increase in adverse effects noted1
Digoxin	No alteration in digoxin pharmacokinetics1 74
NSAIAs	No increase in adverse effects noted1
Paclitaxel	No effect anticipated on paclitaxel metabolism1 113
Phenobarbital	Decreased AUC of montelukast1 102	Montelukast dosage adjustment not recommended;1 monitor for alterations in clinical response and/or adverse effects1
Repaglinide	No effect anticipated on repaglinide metabolism1 113
Rifampin	Potential for decreased montelukast concentrations1	Monitor for alterations in clinical response and/or adverse effects1
Rosiglitazone	No effect anticipated on rosiglitazone pharmacokinetics1 113
Sedative-hypnotics	No increase in adverse effects noted1
Terfenadine (no longer commercially available in US)	No alteration in terfenadine pharmacokinetics; no effect on QTc interval1 103
Theophylline	No clinically important effects on theophylline pharmacokinetics at usual montelukast dosage1 76 Decreased plasma concentrations, AUC, and half-life of theophylline at higher than recommended montelukast dosages76
Thyroid hormones	No increase in adverse effects noted1
Warfarin	No clinically important effects on warfarin pharmacokinetics; no alteration in PT or INR1 73

Montelukast Sodium Pharmacokinetics

Absorption

Bioavailability

Rapidly absorbed from the GI tract; peak plasma concentrations attained within 3–4, 2–2.5, or 2 hours following oral administration in the fasted state of a single 10-mg film-coated tablet (in adults), 5-mg chewable tablet (in adults), or 4-mg chewable tablet (in children 2–5 years of age), respectively.^{1 13 14 37 53}

Oral bioavailability of the 10-mg tablet in adults is 58–66%; bioavailability of the 5-mg chewable tablet in fasting adults is 73%.¹

Plasma concentration profile following oral administration of montelukast 10 mg in adolescents ≥15 years of age is similar to that in young adults.¹

Plasma concentration profile following oral administration of 4- or 5-mg chewable tablet in children 2–5 or 6–14 years of age, respectively, is similar to the profile in adults receiving 10-mg film-coated tablet.^{1 37 101}

Systemic exposure and variability of plasma concentrations with 4-mg granule formulation in infants 6–11 months of age are greater than the exposure and variability with the 10-mg film-coated tablet in adults.¹ Systemic exposure with 4-mg granule formulation in infants 12–23 months of age is less variable than that with the same formulation in younger children but is still greater than that with the 10-mg film-coated tablet in adults.¹

4-mg oral granule formulation and 4-mg chewable tablet are bioequivalent (fasting adults).¹

Bioequivalence of the 10-mg film-coated tablet versus two 5-mg chewable tablets not evaluated.¹

Onset

Improvement in asthma symptoms and/or lung function test results and decreased use of β-agonist bronchodilators are evident after the first dose.^{1 31 45}

Duration

Therapeutic effects persist for at least 24 hours.^{1 31 45}

Food

10-mg tablets: Food does not affect absorption.¹

5-mg chewable tablet: Food decreases extent of absorption.¹ Bioavailability is 63% when administered with a standard meal in the morning.¹

4-mg oral granule formulation: High-fat meal decreases rate of absorption and peak plasma concentration; no effect on AUC.¹ Applesauce does not appear to have a clinically important effect on the pharmacokinetics of montelukast granules.¹

Special Populations

In patients with mild to moderate hepatic impairment, AUC increased 41%.¹

Distribution

Extent

Not fully characterized.^{98 99}

Crosses the placenta in animals (rats, rabbits); not known whether montelukast crosses the placenta in humans.¹

Distributed into milk in rats; not known whether distributed into human milk.¹

Plasma Protein Binding

99%.¹

Elimination

Metabolism

Extensively metabolized in the GI tract and/or liver.^{1 12 20} Several pathways have been identified, including acyl glucuronidation and oxidation catalyzed by CYP3A4 and CYP2C9.^{1 12 20}

Elimination Route

Excreted principally in feces (about 86%) via bile as unchanged drug and metabolites.^{1 12 20}

Half-life

Children 6–14 years of age: 3.4–4.2 hours.³⁷

Adults 19–48 years of age: 2.7–5.5 hours.^{1 13 14 37 51}

Special Populations

In patients with mild to moderate hepatic impairment, elimination half-life prolonged (7.4 hours).^{1 13 51} Pharmacokinetics not evaluated in patients with severe hepatic impairment or hepatitis.¹

In geriatric adults 65–73 years of age, elimination half-life prolonged (6.6 hours).^{1 13 51}

Stability

Storage

Oral

Granules

25°C (may be exposed to 15–30°C).^{1 125} Protect from moisture and light.^{1 125}

Do not store opened packets or granules mixed with food, baby formula, or breast milk for future use.^{1 125} Administer contents within 15 minutes of opening packet.^{1 125}

Tablets, Chewable or Film-coated

25°C (may be exposed to 15–30°C).^{1 125} Protect from moisture and light.^{1 125}

Compatibility

For information on systemic interactions resulting from concomitant use, see Interactions.

Oral

Granules

Granules may be mixed with cold or room temperature soft food; based on stability studies, only applesauce, carrots, rice, or ice cream should be used.^{1 125}

ActionsActions

• 
  

  Selective, competitive leukotriene-receptor antagonist.^{1 2 3 4 5 6 7 8 9 10 11 12 13 14 30 31 44 45 51 53 54 55 56 57 58 105}

  
  


• 
  

  Binds selectively and with high affinity to a group of cysteinyl leukotriene receptors (CysLT₁) in airway smooth muscle ^{1 2 4 5 6 7 8 9 10 11 12 13 14 30 45 51} and competitively inhibits the action of LTD₄ (a cysteinyl leukotriene) at these receptors.^{1 2 4 5 6 7 8 9 10 11 12 13 14 30 51 58 100}

  
  


• 
  

  Modification of leukotriene activity may be used to reduce symptoms of asthma,^{1 2 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 30 44 45 47 58} since cysteinyl leukotrienes are especially important in the pathogenesis of asthma, causing increased mucus secretion and vascular permeability, airway edema, bronchoconstriction, and altered cellular activity associated with the inflammatory process.^{1 2 4 5 23 24 30 53 57 58}

  
  


• 
  

  Inhibits bronchoconstriction induced by exposure to known precipitating factors (e.g., allergens, cold and/or dry air, exercise);^{80 89} inhibits both the acute bronchoconstrictor response and the delayed inflammatory response to inhaled antigen.^{1 30 41 44 47 51 55}

  
  


• 
  

  May be used to reduce symptoms associated with allergic rhinitis, since cysteinyl leukotrienes are released from the nasal mucosa after allergen exposure during the early- and late-phase reactions and are associated with symptoms of allergic rhinitis.¹

  
  


• 
  

  Has essentially no affinity for prostanoid, cholinergic or β-adrenergic receptors.^{1 30}

  
  

Advice to Patients

• 
  

  Importance of patient and/or caregiver reading the manufacturer's patient information prior to initiation of therapy and with each prescription refill.¹²⁵

  
  


• 
  

  Importance of taking montelukast exactly as prescribed and not exceeding recommended frequency of use.¹²⁵

  
  


• 
  

  Importance of taking montelukast at regular intervals, when asymptomatic as well as during periods of worsening asthma.^{1 125}

  
  


• 
  

  Importance of taking montelukast at least 2 hours prior to exercise for prevention of exercise-induced bronchospasm.¹²⁵

  
  


• 
  

  Importance of advising patients who are receiving montelukast for chronic asthma or allergic rhinitis not to use an additional dose for the prevention of exercise-induced bronchospasm.¹²⁵

  
  


• 
  

  Importance of contacting clinician promptly if asthma is not well controlled; seek medical attention if short-acting, inhaled β₂-adrenergic bronchodilators are needed more often than usual or if the maximum number of inhalations for a 24-hour period are exceeded.^{1 125}

  
  


• 
  

  Importance of not using montelukast for the relief of acute bronchospasm.^{1 125} Patients should be provided with and instructed in the use of a short-acting, inhaled β₂-adrenergic bronchodilator as supplemental therapy for acute asthma symptoms.^{1 125}

  
  


• 
  

  Importance of not discontinuing or reducing the dosage of other antiasthmatic agents unless instructed to do so by the clinician.¹

  
  


• 
  

  In patients with known aspirin sensitivity, importance of continuing to avoid aspirin and NSAIAs.^{1 81 125}

  
  


• 
  

  Importance of informing clinicians immediately if symptoms of Churg-Strauss syndrome (e.g., feeling of pins and needles or numbness of extremities, flu-like symptoms, rash, sinusitis) occur.¹²⁵

  
  


• 
  

  Importance of informing clinicians if behavior or mood changes occur.^{1 125 127}

  
  


• 
  

  Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.^{1 125}

  
  


• 
  

  Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses (e.g., allergies).^{1 125}

  
  


• 
  

  Importance of informing patients of other important precautionary information.¹ (See Cautions.)

  
  

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Montelukast Sodium

Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Granules	4 mg (of montelukast) per packet	Singulair	Merck
	Tablets, chewable	4 mg (of montelukast)	Singulair	Merck
		5 mg (of montelukast)	Singulair	Merck
	Tablets, film-coated	10 mg (of montelukast)	Singulair	Merck

Comparative Pricing

This pricing information is subject to change at the sole discretion of DS Pharmacy. This pricing information was updated 03/2011. Actual costs to patients will vary depending on the use of specific retail or mail-order locations and health insurance copays.

Singulair 10MG Tablets (MERCK SHARP &amp; DOHME): 30/$140.36 or 90/$405.14

Singulair 4MG Chewable Tablets (MERCK SHARP &amp; DOHME): 30/$143.99 or 90/$400.99

Singulair 4MG Packet (MERCK SHARP &amp; DOHME): 30/$145.66 or 90/$422.39

Singulair 5MG Chewable Tablets (MERCK SHARP &amp; DOHME): 30/$144.53 or 90/$400.24

Disclaimer

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. and Drugs.com represent that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. and Drugs.com make no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. and Drugs.com do not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS Drug Information. © Copyright, 1959-2011, Selected Revisions July 2010. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.

† Use is not currently included in the labeling approved by the US Food and Drug Administration.

References

1. Merck & Co. Singulair (montelukast sodium) tablets, chewable tablets, and oral granules prescribing information. Whitehouse Station, NJ; 2009 Aug.

2. Hay DWP. Pharmacology of leukotriene receptor antagonists: more than inhibitors of bronchoconstriction. Chest. 1997; 111(Suppl):35-45S.

3. Thibert R, Mach H, Clas SD et al. Characterization of the self-association properties of a leukotriene D₄ receptor antagonist, MK-0476. Int J Pharm. 1996; 134:59-70.

4. Drazen JM. Pharmacology of leukotriene receptor antagonists and 5-lipoxygenase inhibitors in