Montelukast Almus Pharmaceuticals (Montelukast Sodium)

Montelukast, a leukotriene receptor antagonist, is used to manage respiratory allergic conditions by blocking leukotriene-mediated inflammation.

• Asthma: reduces airway inflammation and bronchoconstriction, helping achieve better control of persistent asthma symptoms and decreasing the frequency of exacerbations.
• Allergic rhinitis: alleviates nasal congestion, sneezing and itching associated with seasonal or perennial allergic rhinitis, and improves daily nasal airflow.
• Exercise‑induced bronchoconstriction: prevents bronchospasm triggered by physical activity, allowing improved exercise tolerance and reducing post‑exercise respiratory symptoms.
• Pediatric asthma: assists in controlling symptoms and reducing nighttime awakenings in children aged 2‑12 years.

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1 on airway smooth‑muscle cells, mast cells and eosinophils. By antagonizing this receptor, it prevents leukotriene D4 from binding, thereby inhibiting leukotriene‑mediated bronchoconstriction, mucus secretion, vascular permeability and inflammatory cell recruitment that contribute to asthma and allergic rhinitis symptoms. It also reduces airway hyper‑responsiveness and stabilises mast‑cell activity, contributing to overall symptom control.

Montelukast may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Headache: mild to moderate headache reported in many patients.
• Abdominal pain: discomfort or pain in the stomach area.
• Cough: occasional dry cough.
• Nausea: feeling of sickness or urge to vomit.
• Dizziness: transient light‑headedness.
• Fatigue: general tiredness or lack of energy.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips, tongue or throat that may compromise breathing.
• Mood changes: depression, anxiety, or suicidal thoughts.
• Hepatic enzyme elevation: increased liver function test results.
• Stevens‑Johnson syndrome: severe skin reaction with blistering and detachment.
• Eosinophilic pneumonia: inflammation of lung tissue with eosinophil accumulation.
• Anaphylaxis: life‑threatening allergic reaction.

Before prescribing Montelukast, clinicians should consider several precautionary measures to ensure safe use.

• Assess asthma control: verify that current therapy is optimized before adding Montelukast.
• Monitor neuropsychiatric symptoms: watch for depression, anxiety or suicidal ideation during treatment.
• Use caution in hepatic impairment: adjust use if liver disease is present.
• Avoid in known hypersensitivity: discontinue if allergic reaction to Montelukast occurs.
• Store at room temperature: keep in original packaging, protect from moisture and heat.

Montelukast can interact with other medicines, affecting its plasma levels or therapeutic effect.

Major Interactions (Avoid)

• Ritonavir: may increase montelukast concentrations, raising risk of side effects.
• Phenobarbital: may lower montelukast levels, reducing efficacy.
• Carbamazepine: can markedly decrease montelukast exposure.

Moderate Interactions (Monitor Closely)

• Fluconazole: may modestly increase montelukast levels; monitor for adverse effects.
• Warfarin: potential alteration of INR; regular coagulation monitoring advised.
• Theophylline: possible additive bronchospasm; observe respiratory status.