Montelukast Paediatric (Montelukast)

Montelukast is used to treat conditions mediated by leukotrienes, primarily within the respiratory and allergic disease spectrum.

• Asthma: reduces frequency of attacks and improves symptom control in pediatric patients.
• Exercise‑induced bronchoconstriction: prevents airway narrowing triggered by physical activity.
• Allergic rhinitis: alleviates nasal congestion, sneezing and itching caused by seasonal allergens.

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1 on airway smooth‑muscle cells, mast cells and eosinophils. By antagonizing this receptor, it prevents leukotriene‑mediated bronchoconstriction, mucus secretion and inflammatory cell recruitment, thereby reducing airway hyper‑responsiveness and allergic inflammation. The inhibition is reversible and does not affect prostaglandin pathways, allowing normal physiological responses to persist while specifically targeting the leukotriene cascade implicated in asthma and allergic rhinitis.

Montelukast may be associated with a range of adverse reactions, which are classified by frequency and severity.

Common Side Effects

• Headache: mild to moderate headache reported in many patients.
• Abdominal pain: occasional stomach discomfort or cramps.
• Cough: transient cough without infection.
• Diarrhoea: loose stools occurring during treatment.
• Nausea: feeling of sickness.
• Fever: low‑grade temperature elevation.

Serious or Rare Side Effects

• Neuropsychiatric events: agitation, anxiety, depression or suicidal thoughts.
• Allergic reactions: rash, urticaria or angioedema.
• Hepatic enzyme elevation: rare increase in liver transaminases.

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

• Assess asthma control: verify that the patient’s asthma is not uncontrolled before initiating therapy.
• Monitor mental health: observe for changes in mood, behavior or suicidal thoughts.
• Evaluate liver function: consider baseline hepatic enzymes in patients with liver disease.
• Use with caution in the elderly: adjust monitoring as pharmacokinetics may differ.
• Avoid in known hypersensitivity: discontinue if rash or angioedema develops.
• Store at ambient temperature: keep below 25 °C, protect from moisture and keep in original packaging.

Montelukast can interact with other medicines, altering its effectiveness or increasing the risk of adverse effects.

Major Interactions (Avoid)

• Phenobarbital: enzyme induction may reduce montelukast plasma concentrations.
• Rifampin: strong CYP3A4 inducer that can lower therapeutic levels.
• St. John’s wort: herbal inducer that may decrease drug exposure.

Moderate Interactions (Monitor Closely)

• Antidepressants (e.g., fluoxetine): may increase risk of neuropsychiatric side effects.
• Antihistamines: additive sedative effects are uncommon but should be observed.
• Warfarin: occasional reports of altered INR; monitor coagulation parameters.