Monkasta (Montelukast)

Monkasta, a leukotriene receptor antagonist, is indicated for conditions driven by cysteinyl leukotriene‑mediated inflammation and bronchoconstriction.

• Asthma: reduces the frequency of wheezing episodes and improves lung function in persistent asthma.
• Exercise‑induced bronchoconstriction: prevents airway narrowing that occurs during or after physical activity.
• Allergic rhinitis: alleviates nasal congestion, sneezing and itching caused by seasonal or perennial allergens.

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1 on airway smooth muscle and inflammatory cells. By antagonizing this receptor, it inhibits leukotriene‑mediated bronchoconstriction, mucus secretion, and vascular permeability, thereby reducing airway inflammation and improving respiratory airflow.

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

Common Side Effects

• Headache: mild to moderate pain often resolving without intervention.
• Abdominal pain: discomfort or cramps in the stomach area.
• Cough: transient irritation of the throat.
• Nasopharyngitis: mild upper respiratory tract infection symptoms.
• Diarrhea: loose stools occurring occasionally.
• Fatigue: feeling unusually tired or weak.

Serious or Rare Side Effects

• Allergic reactions: rash, itching, swelling, or anaphylaxis.
• Neuropsychiatric events: agitation, depression, or suicidal thoughts.
• Stevens‑Johnson syndrome: severe skin blistering and mucosal involvement.
• Hepatotoxicity: abnormal liver enzymes indicating potential liver injury.
• Angioedema: rapid swelling of face, lips, or tongue.
• Churg‑Strauss syndrome: rare vasculitis presenting with asthma worsening and eosinophilia.

Before initiating Monkasta, consider the following safety measures.

• Pregnancy: Category B; use only if the potential benefit justifies the potential risk.
• Breastfeeding: Montelukast is excreted in breast milk; assess risk versus benefit.
• Hepatic impairment: monitor liver function tests in patients with existing liver disease.
• Concomitant asthma therapy: ensure patients continue rescue inhalers for acute symptoms.
• Pediatric use: dosage and safety are determined by the prescriber based on age and weight.
• Store at ambient temperature: keep below 25 °C, retain in the original container, and protect from moisture.

Montelukast may interact with other medicines; awareness of the interaction level helps guide monitoring.

Major Interactions (Avoid)

• Rifampin: strong enzyme inducer that can lower montelukast plasma concentrations.
• Phenobarbital: may reduce therapeutic effect by increasing drug metabolism.

Moderate Interactions (Monitor Closely)

• Warfarin: potential alteration of anticoagulant effect; monitor INR.
• Beta‑blockers: may blunt the bronchodilatory response; observe respiratory status.
• CYP2C9 inhibitors (e.g., fluconazole): could modestly increase montelukast levels.
• Antidepressants (e.g., fluoxetine): monitor for neuropsychiatric side effects.