Montelukast Sodium is indicated for:

• Prevention and long-term management of asthma
• Short-term prevention of exercise-induced bronchoconstriction (EIB)
• Relief of symptoms associated with allergic rhinitis (AR), including both seasonal and perennial types

Montelukast is a selective, orally active leukotriene receptor antagonist that blocks the cysteinyl leukotriene receptor (CysLT1). Cysteinyl leukotrienes (LTC₄, LTD₄, LTE₄) are derived from arachidonic acid metabolism and are released from cells such as mast cells and eosinophils. These leukotrienes play a key role in the pathophysiology of asthma and allergic rhinitis by promoting airway edema, bronchial smooth muscle contraction, and inflammatory cellular activity, all of which contribute to the clinical symptoms of asthma.

Adults and adolescents with asthma or seasonal allergic rhinitis: 

• The dosage for adults and adolescents 15 years of age and older: Montelukast 10 mg tablet once daily.

Pediatric patients with asthma or seasonal allergic rhinitis:

• The dosage for pediatric patients 6 to 14 years of age: Montelukast 5 mg tablet once daily.
• The dosage for pediatric patients 2 years to 5 years of age: Montelukast 4 mg tablet once daily.
• The dosage for pediatric patients 6 months to 5 years of age: Montelukast 4 mg oral granules once daily. This can be administered either directly in the mouth, or mixed with a spoonful of cold water or soft food at room temperature

Use in the pediatric patient: The safety and efficacy of Montelukast have been established in adequate and well-controlled studies in pediatric patients with asthma 6 months to 14 years of age. Safety and efficacy profiles in this age group are similar to those seen in adults.

Hepatic Insufficiency: No dosage adjustment is required in patients with mild-to-moderate hepatic insufficiency.

Renal Insufficiency: No dosage adjustment is recommended in patients with renal insufficiency.

Elderly use: The pharmacokinetic profile and the oral bioavailability of a single 10-mg oral dose of montelukast are similar in elderly and younger adults. The plasma half-life of montelukast is slightly longer in the elderly. No dosage adjustment in the elderly is required.

Montelukast can be safely used alongside other medications commonly prescribed for the prevention and long-term treatment of asthma, without a significant increase in adverse effects. At recommended doses, it does not produce clinically meaningful interactions with drugs such as theophylline, prednisone, prednisolone, oral contraceptives (norethindrone/ethinyl estradiol), terfenadine, digoxin, or warfarin. Clinical studies have also shown no notable adverse interactions when Montelukast is taken with a variety of commonly used medications, including thyroid hormones, sedative-hypnotics, nonsteroidal anti-inflammatory drugs (NSAIDs), benzodiazepines, and decongestants. However, enzyme inducers like phenobarbital can reduce Montelukast exposure (AUC) by about 40%. Despite this reduction, dose adjustment is generally not required. Still, careful clinical monitoring is advised when Montelukast is used with potent cytochrome P450 inducers such as phenobarbital or rifampin.

Montelukast is contraindicated in patients with known hypersensitivity to Montelukast or any of its components.

Common: Diarrhea, fever, gastrointestinal discomfort, headache, nausea, vomiting, skin reactions, and upper respiratory tract infections.

Uncommon: Akathisia, anxiety, joint pain (arthralgia), weakness (asthenia), abnormal behavior, depression, dizziness, drowsiness, dry mouth, bleeding, irritability, malaise, muscle complaints, edema, seizures, abnormal sensations, and sleep disturbances.

Rare: Angioedema, impaired concentration, disorientation, eosinophilic granulomatosis with polyangiitis, erythema nodosum, hallucinations, liver disorders, memory loss, palpitations, pulmonary eosinophilia, suicidal tendencies, and tremor.

Montelukast has been shown to cross the placenta in animal studies (rats and rabbits). However, there are no adequate and well-controlled studies in pregnant women. Therefore, it should be used during pregnancy only when clearly necessary. As many drugs are excreted in human breast milk, caution is advised when Montelukast is administered to breastfeeding mothers.

Montelukast is not intended for the relief of acute bronchospasm, including status asthmaticus, and patients should always have appropriate rescue medication available. Treatment with Montelukast may be continued during acute asthma exacerbations. Although the dose of inhaled corticosteroids may be gradually reduced under medical supervision, Montelukast should not be used as a sudden replacement for inhaled or oral corticosteroids. It is also not recommended as monotherapy for the prevention or management of exercise-induced bronchospasm. Patients with known aspirin sensitivity should continue to avoid aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) while taking Montelukast. While Montelukast can improve airway function in such patients, it does not prevent bronchoconstriction triggered by aspirin or other NSAIDs.

Most cases of Montelukast overdose have not been associated with serious adverse effects. When symptoms do occur, they are generally consistent with its known safety profile and may include abdominal pain, drowsiness, thirst, headache, vomiting, and psychomotor hyperactivity. In case of overdose, standard supportive measures should be taken, such as removing any unabsorbed drug from the gastrointestinal tract, monitoring the patient clinically, and providing supportive treatment as needed.

Leukotriene receptor antagonists

Store in a cool, dry place below 30°C, protected from light and moisture. Keep out of reach of children.