Montelukast Sandoz (Montelukast)

Montelukast Sandoz belongs to the leukotriene receptor antagonist class and is used to manage conditions driven by leukotriene‑mediated inflammation.

• Asthma: improves control of chronic airway inflammation and reduces frequency of bronchospasm episodes.
• Allergic rhinitis: alleviates nasal congestion, sneezing and itchy eyes caused by seasonal or perennial allergens.
• Exercise‑induced bronchoconstriction: prevents airway narrowing that occurs during or after physical activity.

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1 on airway smooth muscle and inflammatory cells. By antagonizing this receptor, it inhibits leukotriene‑induced bronchoconstriction, mucus secretion, vascular permeability and eosinophil recruitment, thereby reducing airway inflammation and hyper‑responsiveness.

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

Common Side Effects

• Headache: mild to moderate pain often resolving without intervention.
• Abdominal pain: discomfort or cramps in the stomach area.
• Cough: transient irritation of the throat.
• Diarrhoea: loose stools that may be self‑limiting.
• Rash: mild skin redness or itching.
• Dizziness: occasional sensation of light‑headedness.

Serious or Rare Side Effects

• Stevens‑Johnson syndrome: severe skin reaction requiring immediate medical attention.
• Angioedema: rapid swelling of face, lips or tongue.
• Hepatic injury: abnormal liver function tests or jaundice.
• Neuropsychiatric events: agitation, depression or suicidal thoughts.
• Anaphylaxis: life‑threatening allergic response.
• Blood dyscrasias: rare cases of neutropenia or thrombocytopenia.

Before initiating therapy, consider the following safety measures.

• Assess liver function: monitor hepatic enzymes in patients with pre‑existing liver disease.
• Review psychiatric history: observe for mood changes or suicidal ideation, especially in adolescents.
• Evaluate concomitant drugs: check for interactions that may alter montelukast exposure.
• Use in pediatric patients: follow age‑specific dosing recommendations provided by the prescriber.
• Avoid in known hypersensitivity: discontinue if allergic reaction occurs.
• Store below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Montelukast may interact with other medicines; clinical relevance varies.

Major Interactions (Avoid)

• Phenobarbital: strong enzyme inducer that can lower montelukast plasma concentrations.
• Rifampin: reduces drug exposure through hepatic CYP3A4 induction.
• St. John’s wort: may decrease effectiveness by increasing metabolic clearance.

Moderate Interactions (Monitor Closely)

• Erythromycin: modest inhibition of metabolism, may increase montelukast levels.
• Fluconazole: can raise drug concentrations slightly.
• Warfarin: occasional reports of altered anticoagulant effect; monitor INR as needed.