Singulair (montelukast sodium) is a leukotriene receptor antagonist (LTRA) prescription medication specifically formulated for the prophylactic and chronic treatment of asthma, the relief of symptoms of seasonal allergic rhinitis (hay fever), and the prevention of exercise-induced bronchoconstriction (EIB). Its mechanism of action targets a key inflammatory pathway, offering a non-steroidal option for managing respiratory inflammation and bronchospasm. This oral tablet, chewable, or granule formulation provides a convenient once-daily dosing regimen, making it a cornerstone in long-term management plans for appropriate patient populations. Clinical evidence supports its efficacy in reducing airway inflammation and improving overall pulmonary function and quality of life.

Features

• Active Pharmaceutical Ingredient: Montelukast sodium.
• Available Formulations: Film-coated tablets (10 mg), chewable tablets (4 mg and 5 mg), and oral granules (4 mg packet).
• Pharmacologic Class: Selective and orally active leukotriene receptor antagonist that inhibits the cysteinyl leukotriene (CysLT1) receptor.
• Dosing Regimen: Administered once daily in the evening for asthma and allergic rhinitis; taken at least 2 hours before exercise for EIB prevention.
• Prescription Status: Available by prescription only.

Benefits

• Provides targeted inhibition of leukotrienes, key mediators of the inflammatory response in asthma and allergies, leading to reduced airway inflammation.
• Effectively prevents asthma symptoms, including nighttime awakening, and reduces the need for rescue inhaled beta2-agonists.
• Offers significant relief from the symptoms of seasonal allergic rhinitis, such as sneezing, nasal congestion, runny nose, and itching.
• Serves as a proven prophylactic agent to prevent exercise-induced bronchoconstriction, allowing for improved physical activity.
• Presents a non-steroidal oral alternative or adjunctive therapy to inhaled corticosteroids, potentially simplifying treatment regimens for some patients.
• Improves overall asthma control and quality of life metrics by providing consistent, 24-hour coverage with a single daily dose.

Common use

Singulair is commonly prescribed for the chronic treatment of asthma in adults and pediatric patients 12 months of age and older. It is indicated for the prophylaxis and chronic treatment of asthma, and it should not be used for the immediate relief of acute asthma attacks. Furthermore, it is approved for the relief of symptoms of seasonal allergic rhinitis in patients aged 2 years and older and for the prevention of exercise-induced bronchoconstriction in patients 6 years of age and older. It is often used as part of a comprehensive asthma management plan, which may include other controller medications.

Dosage and direction

The dosage of Singulair is based on the indication and the age of the patient. It is to be taken orally once a day.

• Asthma and Allergic Rhinitis:
  • Adults and Adolescents (15 years and older): One 10 mg tablet daily.
  • Pediatric Patients (6 to 14 years): One 5 mg chewable tablet daily.
  • Pediatric Patients (2 to 5 years): One 4 mg chewable tablet or one 4 mg packet of oral granules daily.
  • Pediatric Patients (12 to 23 months): One 4 mg chewable tablet or one 4 mg packet of oral granules daily.
• Exercise-Induced Bronchoconstriction:
  • Adults and Adolescents (15 years and older): One 10 mg tablet at least 2 hours before exercise.
  • Pediatric Patients (6 to 14 years): One 5 mg chewable tablet at least 2 hours before exercise.
  • Patients already taking a daily dose for asthma should not take an additional dose for EIB.

The granules can be administered directly in the mouth, dissolved in 5 mL (one teaspoon) of cold or room temperature baby formula or breast milk, or mixed with a spoonful of one of the following soft foods: applesauce, mashed carrots, rice, or ice cream. The entire dose must be administered within 15 minutes of preparation.

Precautions

Patients should be advised that Singulair is not a bronchodilator and should not be used to treat acute episodes of asthma. Acute asthma attacks require an inhaled short-acting beta2-agonist. Patients should have such rescue medication available at all times. Healthcare providers should monitor patients for neuropsychiatric events, as serious side effects affecting behavior and mood have been reported. Patients and caregivers should be instructed to be alert for changes in behavior or thinking, and to report these immediately. Caution is advised in patients with phenylketonuria (PKU), as the chewable tablets contain aspartame, a source of phenylalanine. The oral granules contain sucrose and should be used with caution in patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption, or sucrase-isomaltase insufficiency.

Contraindications

Singulair is contraindicated in patients with known hypersensitivity to montelukast or any other component of the formulation. Hypersensitivity reactions, including anaphylaxis, angioedema, rash, and eosinophilia, have been reported.

Possible side effect

Clinical trials and post-marketing experience have identified a range of possible side effects. Common side effects may include headache, ear infection, sore throat, upper respiratory infection, fever, sinusitis, cough, nausea, diarrhea, otitis media, influenza, rhinorrhea, sinus headache, and wheezing. Serious side effects require immediate medical attention and include:

• Neuropsychiatric events: Agitation, aggressive behavior or hostility, anxiety, depression, disorientation, disturbance in attention, dream abnormalities, hallucinations, insomnia, irritability, memory impairment, obsessive-compulsive symptoms, restlessness, sleepwalking, suicidal thinking and behavior (suicidality), tremor, tic.
• Systemic eosinophilia: Rare cases of eosinophilic conditions, including Churg-Strauss syndrome (a systemic vasculitis), have been reported, often but not exclusively associated with the reduction of oral corticosteroid therapy.
• Allergic reactions: Hypersensitivity reactions including anaphylaxis, angioedema (swelling of the face, lips, tongue, and/or throat), rash, and hives.

Drug interaction

Formal drug interaction studies have shown Singulair to have no clinically significant interactions with a wide range of common medications, including prednisone, digoxin, warfarin, terfenadine, theophylline, and oral contraceptives. It is extensively metabolized by cytochrome P450 enzymes. Phenobarbital, which induces CYP enzyme activity, has been shown to decrease the AUC of montelukast; however, no dosage adjustment is recommended. Rifampin, another potent enzyme inducer, may also reduce systemic exposure. It is always imperative to inform your healthcare provider of all prescription, over-the-counter, and herbal products you are taking.

Missed dose

If a dose is missed, it should be taken as soon as it is remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped and the regular dosing schedule resumed. Patients should not take a double dose to make up for a missed one.

Overdose

In the event of an overdose, supportive and symptomatic treatment is recommended. There is no specific antidote. Clinical experience with overdose is limited. The most frequently reported symptoms included thirst, sleepiness, vomiting, psychomotor hyperactivity, and headache. The pharmacokinetics of montelukast are linear, and it is not dialyzable via peritoneal or hemodialysis. Standard measures to eliminate unabsorbed drug from the GI tract should be employed if appropriate.

Storage

Singulair should be stored at room temperature, 20°C to 25°C (68°F to 77°F), in the original container or package. It must be protected from moisture and light. The oral granules must be used within 15 minutes of opening the packet and should not be stored once mixed with food or liquid. Keep all medications out of the reach of children and pets.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read here. The information provided is not exhaustive and may not cover all possible uses, directions, precautions, interactions, or adverse effects.

Reviews

• Clinical Efficacy (4.5/5): “As an adjunct therapy in moderate persistent asthma, montelukast consistently demonstrates a statistically significant improvement in morning PEFR and a reduction in beta-agonist use across multiple double-blind, placebo-controlled studies. Its effect is more pronounced in aspirin-exacerbated respiratory disease (AERD) and exercise-induced phenotypes.” – Pulmonary Specialist
• Patient Adherence (4.7/5): “The once-daily oral dosing is a significant advantage in pediatric and adolescent populations where adherence to inhaled regimens is often suboptimal. The chewable and granule formulations are particularly well-accepted.” – Pediatric Allergist
• Safety Profile (4.0/5): “While generally well-tolerated from a somatic perspective, the black box warning for neuropsychiatric events necessitates careful patient selection, thorough pre-treatment counseling, and vigilant post-marketing surveillance. The benefits typically outweigh the risks, but this requires an informed and proactive approach to patient management.” – Clinical Pharmacologist