Montelukast: clinical use

Prescribing considerations

• Do not use for an acute asthma attack; ensure access to rescue treatment.
• Use as add-on therapy where licensed. Do not abruptly substitute it for inhaled corticosteroids.
• Explain neuropsychiatric risks and advise prompt reporting of symptoms.
• Reassess benefit if asthma control remains inadequate or deteriorates.
• Continued avoidance of triggering aspirin or NSAIDs is necessary in aspirin-sensitive asthma.

Contraindications and cautions

• Hypersensitivity to montelukast or any formulation excipient.
• Check formulation-specific excipients: chewable tablets may contain aspartame and require consideration in phenylketonuria; some film-coated products contain lactose.
• No clinical data are available for severe hepatic impairment.

Monitoring

• Review asthma control, reliever use and exacerbations.
• Ask about new or worsening neuropsychiatric symptoms; discontinue montelukast if these occur and reassess treatment.
• Assess promptly for systemic eosinophilia or vasculitic features when compatible symptoms occur.
• Investigate possible hepatic injury when clinically indicated.

Clinical pharmacology

Montelukast is a selective, orally active CysLT1-receptor antagonist. It is highly protein-bound, undergoes hepatic metabolism mainly involving CYP2C8 with contributions from CYP2C9 and CYP3A4, and is eliminated predominantly through bile.

Formulation and product differences

• Film-coated tablets are swallowed whole and may be taken with or without food.
• Chewable tablets must be chewed before swallowing, have food-separation requirements and may contain aspartame as a phenylalanine source.
• Granules can be given directly or with cold, soft food; use the opened sachet or prepared mixture promptly.
• Licensed age ranges and indications vary between formulations and products; consult the relevant product information.

Chewable tablet

Route: Oral

Strengths: 4 mg, 5 mg

Granules

Route: Oral

Strengths: 4 mg

Sachet

Route: Oral

Strengths: 4 mg