Montelukast Al (Montelukast)

• Montelukast acts on the leukotriene pathway to control inflammation and bronchoconstriction in respiratory disorders.
• Asthma: improves long‑term control by decreasing airway inflammation and reducing the frequency of wheezing episodes, night symptoms, and the need for rescue inhalers.
• Allergic rhinitis: alleviates nasal congestion, sneezing, and itchy eyes by blocking leukotriene‑mediated inflammation in the nasal mucosa.
• Exercise‑induced bronchoconstriction: prevents narrowing of the airways that occurs during or after physical activity, allowing better tolerance of exercise.

• Montelukast selectively binds to the cysteinyl leukotriene receptor type 1 (CysLT1) on airway smooth‑muscle cells, macrophages, and eosinophils. By blocking the action of leukotrienes C4, D4 and E4, it prevents receptor‑mediated bronchoconstriction, mucus secretion, and inflammatory cell recruitment, thereby reducing airway edema and hyper‑responsiveness. The antagonism is competitive and reversible, leading to sustained inhibition of the leukotriene cascade throughout the dosing interval.

Common Side Effects

• Headache: mild to moderate intensity, often transient.
• Abdominal pain: discomfort in the stomach area, usually resolves without intervention.
• Nausea: feeling of queasiness, may be accompanied by loss of appetite.
• Diarrhea: loose stools that are generally self‑limiting.
• Cough: occasional dry cough reported by some patients.
• Sore throat: irritation or scratchy feeling in the throat.

Serious or Rare Side Effects

• Allergic reactions: rash, angioedema, or anaphylaxis requiring immediate medical attention.
• Neuropsychiatric events: mood changes, agitation, or rare suicidal thoughts.
• Hepatic injury: signs of liver dysfunction such as jaundice or elevated enzymes.
• Severe bronchospasm: paradoxical worsening of breathing difficulty.
• Blood dyscrasias: rare cases of eosinophilia or neutropenia.

Before initiating therapy, consider the following precautions:

• Assess asthma control: ensure baseline control before adding Montelukast.
• Monitor neuropsychiatric symptoms: watch for mood changes or unusual behavior.
• Use with caution in hepatic impairment: dose adjustment may be required.
• Avoid in known hypersensitivity: discontinue if allergic reaction occurs.
• Review concomitant medications: check for potential drug interactions.
• Store at room temperature: keep in the original pack, protect from moisture and direct sunlight.

Montelukast may interact with several medicines; awareness of the following is important.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir): may increase Montelukast plasma levels.
• Concurrent leukotriene modifiers (e.g., zafirlukast): additive effects on leukotriene pathways.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin, phenobarbital): may reduce efficacy.
• Warfarin: monitor INR as Montelukast can affect anticoagulation.
• Oral contraceptives: possible alteration of hormone levels; observe for reduced contraceptive effectiveness.