Montelucaste Ratiopharm (Montelukast Sodium)

Montelukast is a leukotriene receptor antagonist used to manage conditions driven by leukotriene‑mediated inflammation.

• Asthma: reduces frequency and severity of bronchospasm, improving overall symptom control.
• Allergic rhinitis: alleviates nasal congestion, sneezing, itching and watery discharge caused by seasonal or perennial allergens.
• Exercise‑induced bronchoconstriction: prevents airway narrowing that occurs during or after physical activity, allowing better exercise tolerance.

• Montelukast selectively antagonizes the cysteinyl leukotriene receptor CysLT1, inhibiting the actions of leukotriene D4 and related mediators. By blocking this receptor, it reduces bronchial smooth‑muscle contraction, vascular permeability, and inflammatory cell recruitment in the airways, thereby mitigating asthma and allergic symptoms.

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

Common Side Effects

• Headache: mild to moderate intensity, often transient.
• Abdominal pain: discomfort or cramps in the stomach region.
• Nausea: feeling of queasiness, sometimes accompanied by vomiting.
• Dizziness: light‑headed sensation, especially when standing quickly.

Serious or Rare Side Effects

• Allergic reactions: rash, angioedema, or anaphylaxis requiring immediate medical attention.
• Mood changes: depression, anxiety, or suicidal thoughts reported in some patients.
• Hepatic enzyme elevations: abnormal liver function tests that may indicate liver stress.
• Severe skin reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis, though extremely uncommon.

Before initiating therapy, consider the following safety measures.

• Pregnancy: category B; use only if the potential benefit justifies the potential risk to the fetus.
• Breastfeeding: montelukast is excreted in breast milk; evaluate risk versus benefit for the infant.
• Pediatric use: approved for children as young as six months for certain indications; dosing must follow prescriber guidance.
• Drug interactions: review concomitant medications, especially strong CYP3A4 inhibitors or inducers, to avoid altered exposure.
• Renal/hepatic impairment: patients with severe organ dysfunction may require monitoring or dose adjustment.
• Store at ambient temperature: keep below 25 °C, protect from moisture and light, retain in the original container.

Montelukast may interact with several drug classes; monitoring is advised.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir): can increase montelukast plasma levels and risk of side effects.
• CYP inducers (e.g., phenobarbital, rifampin): may reduce therapeutic effectiveness.

Moderate Interactions (Monitor Closely)

• Phenylephrine or pseudoephedrine: may enhance cardiovascular effects such as increased blood pressure.
• Warfarin: monitor INR as montelukast could influence anticoagulant control.
• Beta‑agonists: additive bronchodilator effect may require dose adjustments.