Montelukast Ab (Montelukast Sodium)

• Montelukast is used to treat conditions mediated by cysteinyl leukotrienes, primarily within the respiratory tract, and is effective in both chronic and episodic presentations.
• Asthma: reduces bronchoconstriction and airway inflammation, improves daily symptom control, and lowers the risk of asthma attacks.
• Exercise‑induced bronchoconstriction: prevents airway narrowing triggered by physical activity, enhances exercise tolerance, and reduces post‑exercise respiratory symptoms.
• Allergic rhinitis: alleviates nasal congestion, sneezing, itching and watery discharge by decreasing leukotriene‑mediated inflammation in the nasal mucosa.

• Montelukast selectively antagonizes the cysteinyl leukotriene receptor CysLT1 located on airway smooth‑muscle cells, mast cells and eosinophils. By blocking the binding of leukotriene D4 and related mediators, it prevents the cascade that leads to bronchial smooth‑muscle contraction, vascular permeability, mucus secretion and inflammatory cell recruitment, thereby reducing airway narrowing and inflammation.

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

Common Side Effects

• Headache: mild to moderate pain often transient.
• Upper respiratory tract infection: symptoms such as sore throat or nasal congestion.
• Abdominal pain: discomfort or cramping in the stomach area.
• Cough: persistent dry cough without infection.

Serious or Rare Side Effects

• Neuropsychiatric events: agitation, depression, or suicidal thoughts.
• Allergic reactions: rash, hives, swelling of the face or throat.
• Hepatic dysfunction: elevated liver enzymes or jaundice.

When prescribing Montelukast, clinicians should consider several safety and handling precautions.

• Assess patient history: review asthma severity and prior response to leukotriene modifiers.
• Monitor for neuropsychiatric symptoms: watch for mood changes, depression or suicidal ideation.
• Evaluate liver function: consider baseline tests in patients with hepatic disease.
• Use cautiously in pregnancy: discuss potential risks and benefits with the prescriber.
• Avoid in patients with known hypersensitivity to montelukast or excipients.
• Store at ambient temperature: keep below 25°C, protect from moisture and light in original packaging.

Montelukast can interact with other medicines, influencing its efficacy or safety profile.

Major Interactions (Avoid)

• Phenobarbital, carbamazepine, rifampin: strong enzyme inducers that may reduce montelukast plasma levels.
• Ritonavir or other potent CYP3A4 inhibitors: may increase exposure and risk of adverse effects.

Moderate Interactions (Monitor Closely)

• Warfarin: possible alteration of anticoagulant effect; monitor INR.
• Theophylline: combined use may enhance central nervous system side effects.
• Antidepressants (SSRIs, SNRIs): monitor for additive neuropsychiatric effects.