Montelukast Accord (Montelukast)

Montelukast acts on the leukotriene pathway to control airway inflammation and bronchoconstriction.

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

• Montelukast selectively blocks the cysteinyl leukotriene receptor CysLT1 on airway smooth muscle and inflammatory cells. By antagonizing this receptor, it inhibits leukotriene‑mediated bronchoconstriction, vascular permeability, mucus secretion, and eosinophil recruitment, thereby reducing airway inflammation and hyper‑responsiveness associated with asthma and allergic rhinitis.

Montelukast may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Headache: mild to moderate pain often reported during early treatment.
• Abdominal pain: discomfort or cramping in the stomach area.
• Cough: transient irritation of the throat.
• Nausea: feeling of queasiness without vomiting.
• Dyspepsia: indigestion or upset stomach.
• Fatigue: unusual tiredness or lack of energy.

Serious or Rare Side Effects

• Angioedema: swelling of the face, lips, tongue or throat that may impair breathing.
• Neuropsychiatric events: mood changes, depression, anxiety, or suicidal thoughts.
• Severe allergic reaction: rash, hives, or anaphylaxis requiring immediate medical attention.
• Hepatic injury: abnormal liver function tests or hepatitis.
• Stevens‑Johnson syndrome: rare but serious skin reaction with blistering and detachment.

When prescribing Montelukast, clinicians should consider several precautionary measures to ensure safe use.

• Liver function monitoring: assess hepatic enzymes before initiating therapy and periodically during treatment.
• Neuropsychiatric assessment: watch for mood changes, depression, or suicidal ideation, especially in adolescents.
• Severe hepatic impairment: use with caution or avoid if liver disease is advanced.
• Known hypersensitivity: do not administer to patients with documented allergy to Montelukast or any excipients.
• Concomitant CYP-modulating drugs: review other medicines that may alter Montelukast plasma levels.
• Store at room temperature: keep in the original packaging, protect from moisture and excessive heat.

Montelukast can interact with other medicines; awareness of the interaction level guides clinical decisions.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir): may increase Montelukast exposure and risk of adverse effects.
• Phenobarbital (high‑dose): may markedly reduce Montelukast plasma concentrations, compromising efficacy.

Moderate Interactions (Monitor Closely)

• Rifampin: induces metabolism and can lower drug levels.
• Fluconazole: moderate CYP3A4 inhibition may modestly raise exposure.
• Warfarin: potential for altered anticoagulant effect; monitor INR closely.
• Carbamazepine: enzyme induction may reduce therapeutic levels.