Montelukast Almus (Montelukast Sodium)

• Montelukast acts on the leukotriene pathway to provide long‑term control of several respiratory conditions.
• Asthma: Improves daily symptom control, reduces the frequency and severity of exacerbations, and may decrease the need for rescue inhaler use in patients requiring maintenance therapy.
• Allergic rhinitis: Alleviates nasal congestion, sneezing, itching and watery discharge associated with seasonal or perennial allergic rhinitis, improving overall quality of life.
• Exercise‑induced bronchoconstriction: Prevents airway narrowing triggered by physical activity, allowing better exercise tolerance and reducing post‑exercise respiratory symptoms.

• Montelukast selectively blocks the cysteinyl leukotriene receptor type 1 (CysLT1) on airway smooth‑muscle cells, sub‑mucosal glands and inflammatory cells. By antagonizing CysLT1, it prevents leukotriene‑mediated bronchoconstriction, vascular permeability, mucus secretion and eosinophilic inflammation, thereby contributing to improved airway patency and reduced inflammatory response in the respiratory tract. The inhibition is dose‑dependent and sustained over 24 hours, supporting once‑daily dosing for chronic management in patients with asthma and allergic rhinitis.

Montelukast is generally well tolerated, but a range of adverse reactions have been reported.

Common Side Effects

• Headache: mild to moderate intensity.
• Abdominal pain: intermittent discomfort.
• Cough: non‑productive.
• Nausea: occasional.
• Dyspepsia: indigestion or upset stomach.
• Fatigue: feeling of tiredness.
• Dizziness: transient light‑headedness.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips or airway.
• Stevens‑Johnson syndrome: severe skin rash with blistering.
• Eosinophilic granulomatosis with polyangiitis: systemic vasculitis with eosinophilia.
• Suicidal thoughts or behavior: mood changes requiring immediate medical attention.
• Hepatic injury: elevated liver enzymes or hepatitis.
• Anaphylaxis: severe allergic reaction with hives and breathing difficulty.

• When prescribing Montelukast, several precautions should be considered.
• Assess asthma control: evaluate frequency of symptoms before initiating therapy.
• Monitor neuropsychiatric events: watch for mood changes, depression or suicidal thoughts.
• Use caution in hepatic impairment: adjust therapy if liver disease is present.
• Review concomitant medications: consider potential interactions with CYP inducers.
• Avoid in patients with known hypersensitivity to montelukast or any tablet components.
• Store at room temperature: keep in the original packaging, protect from moisture and heat.

Montelukast may interact with other medicines; awareness of these interactions helps maintain safety and efficacy.

Major Interactions (Avoid)

• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine, phenytoin) can markedly lower montelukast plasma concentrations, potentially reducing therapeutic effect.
• Phenobarbital, a hepatic enzyme inducer, decreases montelukast levels and may necessitate clinical monitoring.
• Co‑administration with other leukotriene antagonists (e.g., zafirlukast) offers no additive benefit and raises the risk of overlapping adverse reactions.

Moderate Interactions (Monitor Closely)

• Antidepressants such as SSRIs or SNRIs may increase the likelihood of neuropsychiatric events when combined with montelukast; patients should be observed for mood changes.
• Antihistamines, particularly when used with CNS depressants, can enhance sedation; dosage adjustments may be required.
• Theophylline metabolism may be altered; clinicians should monitor theophylline serum concentrations during combined therapy.