Montelucaste Accord (Montelukast)

Montelukast is used in the management of leukotriene‑mediated respiratory conditions.

• Asthma: improves control of persistent symptoms and reduces the frequency of exacerbations.
• Exercise‑induced bronchoconstriction: prevents airway narrowing triggered by physical activity.
• Allergic rhinitis: alleviates nasal congestion, sneezing and itchy eyes associated with seasonal allergies.

• Montelukast selectively blocks the cysteinyl leukotriene receptor type 1 (CysLT1) on airway smooth‑muscle cells, sub‑mucosal glands and inflammatory cells. By preventing leukotriene D4 and related mediators from binding, it inhibits bronchoconstriction, mucus secretion and eosinophilic inflammation, thereby improving airway patency and reducing allergic inflammation. The antagonism is dose‑dependent and does not affect prostaglandin pathways, allowing it to be combined with inhaled corticosteroids or bronchodilators for additive benefit.

Montelukast is generally well tolerated, but several adverse reactions have been reported.

Common Side Effects

• Headache: mild to moderate pain often transient.
• Abdominal pain: discomfort or cramps in the stomach area.
• Cough: dry or productive cough unrelated to infection.
• Upper respiratory tract infection: symptoms such as sore throat or nasal congestion.
• Fever: low‑grade temperature increase.
• Diarrhea: loose stools or increased bowel movements.
• Dyspepsia: indigestion or upset stomach.
• Taste disturbance: altered sense of taste.

Serious or Rare Side Effects

• Neuropsychiatric events: agitation, depression, suicidal thoughts or behavior.
• Allergic reactions: rash, pruritus, angioedema or anaphylaxis.
• Hepatic dysfunction: elevated liver enzymes or hepatitis.

When prescribing Montelukast, clinicians should consider several safety precautions.

• Neuropsychiatric monitoring: observe patients for mood changes, depression or suicidal ideation.
• Hepatic impairment: use with caution in patients with liver disease and monitor liver function tests.
• Acute asthma: not indicated for immediate relief of bronchospasm; provide rescue inhaler instead.
• Pregnancy: category B; discuss potential risks and benefits with the patient.
• Drug interactions: review concomitant medications that may alter montelukast exposure.
• Store below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Montelukast may interact with other medicines that affect its metabolism or pharmacodynamic profile.

Major Interactions (Avoid)

• Rifampin, phenobarbital, phenytoin, carbamazepine: strong CYP3A4 inducers that can markedly reduce montelukast plasma concentrations.
• Ketoconazole, itraconazole, fluconazole: potent CYP3A4 inhibitors that may increase exposure and risk of adverse effects.
• Warfarin: concurrent use may enhance anticoagulant effect; monitor INR closely.

Moderate Interactions (Monitor Closely)

• Erythromycin, clarithromycin: moderate CYP3A4 inhibitors; consider dose adjustment or clinical monitoring.
• Oral contraceptives: may slightly increase montelukast levels; monitor for side effects.
• Theophylline: additive bronchodilator effect; observe for excessive bronchodilation.