Montelukast Sandoz Gmbh (Montelukast)

Montelukast acts on the leukotriene pathway to control airway inflammation and bronchoconstriction. It is used for several well‑established respiratory conditions.

• Asthma: reduces frequency of symptoms, improves lung function and decreases need for rescue medication.
• Allergic rhinitis: alleviates nasal congestion, sneezing and itching caused by seasonal or perennial allergens.
• Exercise‑induced bronchoconstriction: prevents narrowing of the airways that occurs during or after physical activity.

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1, preventing leukotrienes D4, C4 and E4 from binding. This inhibition reduces leukotriene‑mediated bronchoconstriction, vascular permeability, mucus secretion and inflammatory cell recruitment in the respiratory tract, thereby improving airway patency and decreasing 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.
• Diarrhoea: self‑limiting.
• Rash: mild skin irritation.

Serious or Rare Side Effects

• Mood changes: including agitation, depression or suicidal thoughts.
• Angio‑edema: swelling of lips, tongue or face.
• Hepatic enzyme elevation: abnormal liver function tests.
• Anaphylaxis: rare severe allergic reaction.
• Stevens‑Johnson syndrome: severe skin reaction.
• Blood dyscrasias: rare hematologic abnormalities.

Before initiating therapy, consider the following safety measures.

• Pregnancy: Category B – use only if clearly needed after risk‑benefit assessment.
• Lactation: Small amounts excreted in breast milk; weigh benefits against potential infant exposure.
• Hepatic impairment: Monitor liver function in patients with existing liver disease.
• Psychiatric history: Observe for mood alterations, especially in adolescents.
• Concomitant asthma therapy: Do not replace inhaled corticosteroids; use as add‑on therapy.
• Store at ambient temperature: keep below 25 °C, protect from moisture and keep in original packaging.

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

Major Interactions (Avoid)

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

Moderate Interactions (Monitor Closely)

• Warfarin: occasional reports of altered INR; monitor coagulation parameters.
• Beta‑agonists: additive bronchodilator effect; assess clinical response.
• Antidepressants (SSRIs, SNRIs): potential for increased neuropsychiatric events.
• Antifungal azoles (ketoconazole, itraconazole): may increase montelukast levels.
• Oral contraceptives: no clinically significant effect, but monitor for any unexpected changes.