What is the recommended dosing of montelukast for adults and children for asthma maintenance and allergic rhinitis?

Montelukast Dosing Recommendations

Montelukast dosing is age-specific: adults and adolescents ≥15 years receive 10 mg once daily, children 6-14 years receive 5 mg once daily, children 2-5 years receive 4 mg once daily, and infants 6-23 months receive 4 mg oral granules once daily for both asthma maintenance and allergic rhinitis. 1

Age-Specific Dosing by Formulation

Adults and Adolescents (≥15 years)

• 10 mg film-coated tablet once daily for asthma maintenance and allergic rhinitis 1, 2
• The 10-mg dose was selected based on dose-ranging studies showing a flat dose-response curve, with doses >10 mg producing no additional efficacy 3

School-Age Children (6-14 years)

• 5 mg chewable tablet once daily 1, 4
• This dose provides systemic exposure similar to the 10-mg adult dose and was validated through pharmacokinetic studies 1, 5
• Effective for both asthma control and allergic rhinitis 3, 6

Preschool Children (2-5 years)

• 4 mg chewable tablet once daily 1, 4
• The 4-mg oral granule formulation is bioequivalent to the 4-mg chewable tablet and can be used as an alternative 1
• Demonstrated efficacy in multiple parameters of asthma control in this age group 7

Infants (6-23 months)

• 4 mg oral granules once daily 4, 1
• FDA-approved for asthma starting at 6 months and perennial allergic rhinitis starting at 6 months 4
• For seasonal allergic rhinitis, approval begins at 2 years of age 4
• Note: Systemic exposure is 60-89% higher in infants 6-11 months compared to adults, though this has not required dose adjustment 1

Critical Safety Considerations

FDA Black Box Warning

Before prescribing montelukast to any patient, especially children, explicit counseling about neuropsychiatric risks is mandatory 4:

• Serious neuropsychiatric events including suicidal thoughts and actions, depression, anxiety, sleep disturbances, and behavioral changes 4
• Monitor for unusual behavioral or mood changes, particularly in the first weeks of therapy 4
• Safer alternatives (inhaled corticosteroids) should be discussed and considered first 4

Common Adverse Events in Infants

In infants 6-23 months, adverse events (≥2% frequency, more than placebo) include upper respiratory infection, wheezing, otitis media, pharyngitis, tonsillitis, cough, and rhinitis 4

Clinical Positioning and Timing

Onset of Action

• Clinical benefit evident within 1 day of starting therapy in young children 7
• Onset occurs by the second day of daily treatment in most patients 4
• Must be taken continuously daily to maintain efficacy 4

Role in Asthma Management

Montelukast is NOT first-line therapy for asthma 3, 4:

• Inhaled corticosteroids (ICS) are superior to montelukast for asthma control in children with mild-to-moderate persistent asthma, with a number needed to treat (NNT) of approximately 6.5 3
• Montelukast should be considered as an alternative when ICS cannot be used or compliance is problematic 4
• Should not be used as monotherapy for moderate-to-severe persistent asthma 4
• Less effective than long-acting beta-agonists as add-on therapy to ICS 3

Dual Indication Advantage

• For patients with both asthma and allergic rhinitis, montelukast offers dual benefit since it is approved for both conditions 4, 2
• This can simplify treatment regimens and improve compliance 2

Administration Considerations

Dosing Flexibility

• Once-daily administration provides superior compliance compared to inhaled therapies 4, 6
• Can be taken at any time of day, though evening dosing is traditional 3
• For the 4-mg oral granules: can be administered directly in the mouth, dissolved in formula/breast milk, or mixed with soft foods 1

Drug Interactions

• No clinically significant interactions with theophylline, warfarin, digoxin, oral contraceptives, or prednisone 1
• Phenobarbital decreases montelukast AUC by approximately 40%, though no dose adjustment is recommended 1

Special Populations

• No dose adjustment required in elderly patients 1
• No dose adjustment in mild-to-moderate hepatic insufficiency (41% higher AUC but elimination only slightly prolonged) 1
• No dose adjustment in renal insufficiency (drug not excreted in urine) 1

Important Clinical Caveats

• Do not use for acute asthma exacerbations or rescue therapy 4
• Ensure patients have a short-acting beta-agonist available for acute symptoms 4
• May attenuate exercise-induced bronchospasm but is less effective than ICS therapy 3
• No tachyphylaxis observed with long-term use (up to 140 weeks in adults, 80 weeks in children) 7