Montelukast is a potent, selective, and orally active leukotriene receptor antagonist (LTRA) that blocks the action of cysteinyl leukotrienes (CysLTs) at the CysLT1 receptor. It is a cornerstone in the prophylactic and chronic treatment of asthma and allergic rhinitis, offering a non-steroidal anti-inflammatory option. It is particularly valued for its once-daily dosing, oral bioavailability, and favorable safety profile in the Indian context.
Adult: 10 mg once daily in the evening for asthma and allergic rhinitis. For EIB, a single 10 mg dose at least 2 hours before exercise; no additional dose within 24 hours.
Note: Can be taken with or without food. The tablet should be swallowed whole with water. For granules: Can be administered directly in the mouth, dissolved in 5 mL of cold or room temperature baby formula/breast milk, or mixed with a spoonful of soft food (applesauce, carrots, rice, ice cream). Do not dissolve in liquid other than specified. Once opened, the entire sachet must be used immediately.
Montelukast selectively and competitively inhibits the cysteinyl leukotriene type 1 (CysLT1) receptor. Cysteinyl leukotrienes (LTC4, LTD4, LTE4) are potent inflammatory eicosanoids released from mast cells, eosinophils, and other cells in the airway. By blocking their receptor, montelukast inhibits the bronchoconstrictor and pro-inflammatory effects of these mediators.
Pregnancy: Pregnancy Category B (US FDA). Animal studies show no risk, but adequate and well-controlled studies in pregnant women are lacking. Use only if clearly needed, weighing potential benefits against risks. Indian guidelines recommend caution.
Driving: Montelukast has been reported to cause dizziness and drowsiness in some patients. Patients should assess their individual response before driving or operating machinery.
| Phenobarbital, Rifampicin | Inducers of CYP450 enzymes may decrease montelukast plasma concentrations. Clinical significance is unclear but monitor for reduced efficacy. | Moderate |
| Gemfibrozil | Inhibitor of CYP2C8/CYP2C9; may increase montelukast plasma concentration. Monitor for increased side effects. | Moderate |
| Prednisone, other systemic corticosteroids | Montelukast allows for a reduction in steroid dose in some patients. Taper steroids cautiously under medical supervision. | Moderate |
| Aspirin, NSAIDs | No direct pharmacokinetic interaction. Montelukast is used to treat reactions in aspirin-exacerbated respiratory disease. | None |