Montelukast Alter (Montelukast Sodium)

Montelukast is indicated for conditions involving leukotriene‑mediated airway inflammation and bronchoconstriction.

• Asthma: reduces frequency of asthma exacerbations and improves overall lung function.
• Allergic rhinitis: alleviates nasal congestion, sneezing and itchy eyes caused by seasonal or perennial allergens.
• Exercise‑induced bronchoconstriction: prevents airway narrowing during or after physical activity.

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1, preventing leukotriene D4 from binding to airway smooth‑muscle and inflammatory cells. By inhibiting this pathway, it reduces leukotriene‑induced bronchoconstriction, mucus secretion, vascular permeability, and eosinophilic inflammation, thereby improving airway patency and decreasing allergic responses. The antagonism also diminishes recruitment of inflammatory mediators, contributing to long‑term control of chronic respiratory symptoms and improves patient quality of life.

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

Common Side Effects

• Headache: mild to moderate pain often reported.
• Upper respiratory tract infection: symptoms such as sore throat or nasal congestion.
• Abdominal pain: discomfort or cramps in the stomach area.
• Cough: occasional dry or productive cough.
• Dizziness: feeling light‑headed or unsteady.
• Diarrhea: loose stools.

Serious or Rare Side Effects

• Allergic reactions: rash, itching, swelling, or anaphylaxis.
• Neuropsychiatric events: mood changes, depression, or suicidal thoughts.
• Hepatic dysfunction: elevated liver enzymes or hepatitis.
• Blood disorders: neutropenia or eosinophilia.
• Angioedema: rapid swelling of face, lips, or tongue.

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

• Pregnancy: safety not fully established; use only if benefits outweigh risks.
• Breastfeeding: limited data; monitor infant for possible effects.
• Age restrictions: not recommended for children under 12 months for asthma; follow local labeling.
• Concomitant medications: assess for potential drug interactions, especially with CYP450 modulators.
• Hepatic impairment: use with caution in patients with liver disease.
• Store at ambient temperature: keep below 25°C, protect from moisture and light in original packaging.

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

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce montelukast plasma levels.
• Phenobarbital: may decrease therapeutic effect.

Moderate Interactions (Monitor Closely)

• Fluconazole: potential increase in montelukast exposure.
• Warfarin: monitor INR as montelukast may affect anticoagulation.
• Beta‑agonists: additive bronchodilation effect; monitor for excessive relief.