Montelukast Ratiopharm (Montelukast Sodium)

Montelukast acts on the leukotriene pathway to control airway and nasal inflammation.

• Asthma: improves control of chronic asthma and reduces frequency of exacerbations.
• Exercise‑induced bronchoconstriction: prevents narrowing of airways triggered by physical activity.
• Allergic rhinitis: alleviates nasal congestion, sneezing and itching associated with seasonal allergies.

• Montelukast selectively antagonizes the cysteinyl leukotriene receptor CysLT1, blocking the actions of leukotrienes D4, C4, and E4. By inhibiting these mediators, it reduces bronchoconstriction, vascular permeability, and inflammatory cell recruitment in the respiratory tract, thereby improving airway patency and decreasing nasal inflammation.

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

Common Side Effects

• Headache: mild to moderate intensity.
• Upper respiratory tract infection: transient symptoms.
• Abdominal pain: occasional discomfort.
• Cough: non‑productive.
• Diarrhea: mild episodes.
• Rash: mild skin irritation.

Serious or Rare Side Effects

• Mood changes: including depression or suicidal thoughts.
• Allergic reactions: such as angioedema or anaphylaxis.
• Hepatotoxicity: elevated liver enzymes.
• Stevens‑Johnson syndrome: severe skin eruption.
• Churg‑Strauss syndrome: vasculitis with eosinophilia.
• Severe bronchospasm: paradoxical worsening of breathing.

Before initiating therapy, consider the following precautions:

• Pregnancy: safety not established; discuss risks with a healthcare provider.
• Breastfeeding: assess benefit‑risk balance before use.
• Hepatic impairment: use with caution in patients with liver disease.
• Concomitant asthma therapy: do not replace inhaled corticosteroids or bronchodilators.
• Monitoring: observe for neuropsychiatric symptoms, especially in children.
• Store at ambient temperature: keep below 25°C, retain in original packaging, protect from moisture and direct sunlight.

Montelukast may interact with several medicines; awareness of interaction severity is important.

Major Interactions (Avoid)

• Phenobarbital: may reduce montelukast plasma concentrations.
• Rifampin: strong enzyme inducer that can lower drug exposure.

Moderate Interactions (Monitor Closely)

• Antidepressants (e.g., fluoxetine): potential for additive neuropsychiatric effects.
• Antihistamines: may increase risk of drowsiness.
• CYP2C9 inhibitors (e.g., fluconazole): could modestly raise montelukast levels.
• Warfarin: monitor INR as theoretical interaction exists.
• Oral contraceptives: no clinically significant effect, but monitor for any unexpected changes.