Montelukast Teva (Montelukast Sodium)

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

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

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1 on airway smooth‑muscle cells, mast cells and eosinophils. By antagonising the actions of leukotrienes D4, C4 and E4, it inhibits bronchoconstriction, vascular permeability and inflammatory cell recruitment, thereby reducing airway narrowing and mucosal edema associated with asthma and allergic rhinitis. The inhibition also dampens the release of pro‑inflammatory mediators, contributing to overall airway stability.

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

Common Side Effects

• Headache: mild to moderate pain in the head.
• Upper respiratory tract infection: sore throat, nasal congestion or cough.
• Abdominal pain: discomfort or cramping in the stomach area.
• Cough: occasional dry or productive cough.
• Nausea: feeling of queasiness or urge to vomit.
• Diarrhea: loose, watery stools.

Serious or Rare Side Effects

• Neuropsychiatric events: agitation, depression, or suicidal thoughts.
• Allergic reactions: rash, pruritus, angioedema, or anaphylaxis.
• Hepatic dysfunction: elevated liver enzymes or jaundice.

Before prescribing Montelukast, clinicians should consider several safety and handling precautions.

• Indication review: confirm diagnosis of asthma, exercise‑induced bronchoconstriction or allergic rhinitis before use.
• Age considerations: safety data are limited in children under 12 months; use only as directed by a pediatric specialist.
• Concomitant medications: assess for potential interactions, especially with phenobarbital or rifampin.
• Monitoring: observe patients for new or worsening neuropsychiatric symptoms during therapy.
• Pregnancy and lactation: evaluate risk‑benefit; limited data are available.
• Store at ambient temperature: keep below 25 °C in the original container, protect from moisture and direct sunlight.

Montelukast may interact with other medicines, altering its effectiveness or safety profile.

Major Interactions (Avoid)

• Phenobarbital: enzyme induction may reduce montelukast plasma levels.
• Rifampin: strong CYP3A4 inducer that can lower therapeutic exposure.
• St. John’s wort: herbal CYP3A4 inducer potentially decreasing efficacy.

Moderate Interactions (Monitor Closely)

• Antidepressants (SSRIs, SNRIs): may increase risk of neuropsychiatric side effects.
• Warfarin: occasional reports of altered INR; monitor coagulation parameters.
• Beta‑agonists: combined use may enhance bronchodilation but requires clinical assessment.