Montelukast Mylan (Montelukast)

Montelukast is a leukotriene‑blocking agent used in chronic respiratory and allergic conditions.

• Asthma: improves control of persistent asthma and reduces exacerbations.
• Allergic rhinitis: relieves nasal congestion, sneezing and itching caused by seasonal or perennial allergens.
• Exercise‑induced bronchoconstriction: prevents airway narrowing that occurs during or after physical activity.

• Montelukast selectively antagonizes the cysteinyl leukotriene receptor CysLT1, blocking the action of leukotriene D4. This inhibition reduces leukotriene‑mediated bronchoconstriction, vascular permeability, and inflammatory cell recruitment in the airways, thereby improving airflow and decreasing allergic inflammation.

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

Common Side Effects

• Headache: mild to moderate pain often reported during early therapy.
• Abdominal pain: discomfort or cramping in the stomach region.
• Nausea: feeling of queasiness without vomiting.
• Diarrhoea: loose, watery stools.
• Cough: transient irritation of the throat.
• Fatigue: unusual tiredness or lack of energy.

Serious or Rare Side Effects

• Allergic reactions: rash, urticaria, or angioedema requiring medical attention.
• Mood changes: depression, anxiety, or suicidal thoughts.
• Hepatic enzyme elevation: abnormal liver function tests.
• Stevens‑Johnson syndrome: severe skin blistering and mucosal involvement.
• Eosinophilic granulomatosis with polyangiitis: rare vasculitic disorder.
• Hemorrhagic events: unusual bruising or bleeding.

Montelukast should be used with awareness of specific safety considerations.

• Monitor liver function: periodic testing is advised for patients with hepatic disease.
• Caution in psychiatric history: observe for mood alterations or suicidal ideation.
• Adjust in renal impairment: dose may need modification in severe kidney dysfunction.
• Avoid in known hypersensitivity: discontinue if allergic reaction occurs.
• Use in pregnancy only if benefit outweighs risk: limited data are available.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Montelukast may interact with other medicines, requiring attention to the level of interaction.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole): may increase montelukast plasma concentrations.
• Phenobarbital or rifampin: can markedly reduce montelukast effectiveness.
• Warfarin: concurrent use may enhance anticoagulant effect, requiring INR monitoring.

Moderate Interactions (Monitor Closely)

• Antidepressants (SSRIs, SNRIs): may increase risk of neuropsychiatric events.
• Beta‑agonists: additive bronchodilator effect may occur.
• Theophylline: monitor for possible changes in respiratory symptoms.