Montelukast Pensa (Montelukast Sodium)

Montelukast, a leukotriene receptor antagonist, is used to manage conditions mediated by cysteinyl leukotrienes.

• Asthma (maintenance therapy): reduces the frequency of asthma attacks and improves overall disease control.
• Allergic rhinitis: alleviates nasal congestion, sneezing, itching and rhinorrhea associated with seasonal or perennial allergies.
• Exercise‑induced bronchoconstriction: prevents bronchospasm triggered by physical activity, allowing better exercise tolerance.

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1, preventing leukotriene D4 and related mediators from binding. By inhibiting this pathway, it reduces bronchoconstriction, mucus secretion, vascular permeability, and inflammatory cell recruitment in the airways, thereby improving respiratory function and allergic symptom control.

Montelukast is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Headache: mild to moderate intensity.
• Abdominal pain: occasional discomfort or cramping.
• Cough: transient dry cough.
• Sore throat: mild irritation of the throat.
• Nausea: occasional upset stomach.
• Dizziness: brief episodes of light‑headedness.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips, tongue or throat.
• Stevens‑Johnson syndrome: severe skin rash with blistering.
• Anaphylaxis: rapid onset of life‑threatening allergic reaction.
• Neuropsychiatric events: mood changes, depression or suicidal thoughts.
• Hepatic injury: abnormal liver function tests.
• Eosinophilic granulomatosis with polyangiitis: rare vasculitic disorder.

Before prescribing Montelukast, clinicians should consider several safety aspects.

• Neuropsychiatric monitoring: watch for mood changes, depression or suicidal ideation.
• Hepatic function: use with caution in patients with liver impairment.
• Hypersensitivity: avoid in individuals with known allergy to montelukast or any excipients.
• Pregnancy and lactation: prescribe only if potential benefit outweighs risk.
• Pediatric use: follow age‑specific labeling and monitor growth parameters.
• Store at below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Montelukast may interact with other medicines that affect its metabolism or pharmacodynamic profile.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir): may increase montelukast plasma concentrations.
• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce therapeutic effect.
• Phenobarbital: significant reduction in montelukast exposure.

Moderate Interactions (Monitor Closely)

• Fluconazole: modest increase in montelukast levels.
• Warfarin: potential alteration of anticoagulant effect; monitor INR.
• Theophylline: possible additive bronchodilator effect; observe for enhanced respiratory response.