Montelukast Crescent Pharma (Montelukast)

Montelukast acts on the leukotriene pathway to control inflammatory airway conditions.

• Asthma: improves control of chronic asthma and reduces the frequency of exacerbations.
• Allergic rhinitis: alleviates nasal congestion, sneezing and itchy eyes associated with seasonal allergies.
• Exercise‑induced bronchoconstriction: prevents airway narrowing that occurs during or after physical activity.

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1, preventing leukotriene D4 from binding. This inhibition reduces leukotriene‑mediated bronchoconstriction, vascular permeability, and inflammatory cell recruitment in the airways, thereby improving respiratory function and decreasing allergic inflammation.

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

Common Side Effects

• Headache: mild to moderate intensity.
• Upper respiratory tract infection: nasopharyngitis or common cold symptoms.
• Abdominal pain: occasional discomfort or cramps.
• Cough: transient dry cough.
• Diarrhoea: loose stools without blood.
• Rash: mild skin erythema or pruritus.

Serious or Rare Side Effects

• Mood changes: depression, anxiety, or suicidal thoughts.
• Allergic reactions: angioedema, urticaria, or anaphylaxis.
• Hepatic dysfunction: elevated liver enzymes.
• Stevens‑Johnson syndrome: severe skin blistering.
• Blood dyscrasias: eosinophilia or neutropenia.
• Cardiovascular events: rare cases of chest pain or palpitations.

Before prescribing Montelukast, consider the following precautions.

• Pregnancy: consult a healthcare professional; safety data are limited.
• Breastfeeding: assess risk versus benefit; drug may be excreted in milk.
• Hepatic impairment: use with caution; monitor liver function if indicated.
• Psychiatric history: monitor for mood changes or suicidal ideation.
• Concomitant asthma therapy: do not replace inhaled corticosteroids without medical guidance.
• Store at ambient temperature: keep below 25 °C, retain in original packaging, and protect from moisture.

Montelukast may interact with other medicines; review patient medication lists.

Major Interactions (Avoid)

• Phenobarbital: may reduce montelukast plasma concentrations.
• Rifampin: induces metabolism, potentially lowering efficacy.

Moderate Interactions (Monitor Closely)

• Antidepressants (e.g., fluoxetine): may increase risk of neuropsychiatric events.
• Warfarin: monitor INR as occasional alterations reported.
• CYP2C9 inhibitors (e.g., fluconazole): may modestly raise montelukast levels.
• Other leukotriene modifiers: avoid combined use due to additive effects.