Monkasta (Montelukast)

• Monkasta (montelukast) acts on leukotriene pathways to control airway inflammation and allergic symptoms.
• Asthma: improves control of chronic airway inflammation, decreases nighttime symptoms, reduces the frequency of exacerbations and may lower the need for rescue bronchodilator use.
• Allergic rhinitis: relieves nasal congestion, sneezing, itching and rhinorrhea caused by allergen exposure, helping to improve daily comfort and sleep quality.
• Exercise‑induced bronchoconstriction: prevents narrowing of the airways during physical activity, allowing better exercise tolerance and reducing the risk of acute bronchospasm.

• Montelukast selectively blocks the cysteinyl leukotriene receptor type 1 (CysLT1) on airway smooth‑muscle cells, glands and inflammatory cells. By antagonising CysLT1, it prevents leukotriene‑mediated bronchoconstriction, mucus secretion and eosinophilic inflammation, thereby improving airway patency and reducing allergic responses. The inhibition is competitive and long‑lasting, allowing once‑daily oral dosing. This mechanism significantly distinguishes it from β2‑agonists which act directly on adrenergic receptors.

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

Common Side Effects

• Headache: mild to moderate head pain reported in clinical use.
• Abdominal pain: discomfort or cramps in the stomach area.
• Cough: persistent dry cough.
• Nausea or diarrhea: gastrointestinal upset.
• Fatigue: feeling unusually tired.
• Dyspepsia: indigestion or upper abdominal discomfort.

Serious or Rare Side Effects

• Angioedema: swelling of face, lips, tongue or throat that may impair breathing.
• Stevens‑Johnson syndrome or toxic epidermal necrolysis: severe skin reactions with blistering and detachment.
• Neuropsychiatric events: agitation, depression, suicidal thoughts or behavior.
• Hepatic enzyme elevation: abnormal liver function tests that may indicate liver involvement.

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

• Assess asthma control: confirm that the patient’s asthma is stable before initiating therapy.
• Monitor for allergic reactions: watch for signs of rash, swelling or breathing difficulty after the first dose.
• Use caution in hepatic impairment: dose adjustment may be needed in patients with liver disease.
• Review pregnancy and lactation status: the safety profile in pregnancy and breastfeeding is not well established.
• Evaluate concomitant medications: consider potential drug‑drug interactions, especially with CYP3A4 inhibitors.
• Store at ambient temperature: keep tablets in the original container, protect from moisture and store below 25 °C.

Montelukast may interact with other medicines; understanding the level of interaction helps guide clinical decisions.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): can increase montelukast plasma concentrations.
• Ritonavir (HIV protease inhibitor): may markedly raise montelukast levels and increase risk of adverse effects.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampicin, phenobarbital, carbamazepine): may reduce montelukast efficacy.
• Warfarin: concurrent use may require monitoring of INR due to possible altered anticoagulant effect.
• Other leukotriene modifiers: combined use can increase risk of side‑effects without added benefit.