Clinical beta

FMBM is currently in clinical beta. Content is for professional review/testing and must not replace local protocols, senior clinical judgment, or official prescribing references.

Drug Monograph

Montelukast

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USE IF: Asthma maintenance (mild persistent or adjunct); allergic rhinitis; exercise-induced bronchoconstriction prevention — with ICS where indicated and clear counseling on neuropsychiatric vigilance.

AVOID IF: Acute asthma exacerbation as rescue; replacing ICS in moderate–severe asthma; continuing without benefit or with new mood/behavior/sleep changes without reassessment.

Montelukast

Leukotriene receptor antagonist (LTRA)

AdultPediatricsAsthmaAllergic rhinitisOutpatientWardER

Indication

Asthma maintenance • Allergic rhinitis • EIB prevention (not rescue)

At a glance

INDICATIONS (CORE USE)

- Asthma (maintenance; mild persistent or adjunct) - Allergic rhinitis - Exercise-induced bronchoconstriction (prevention)

ADULT DOSE (STANDARD)

10 mg PO once daily (often evening) Not for acute relief

MAX DOSE

Fixed by age/formulation per labeling — do not exceed recommended daily dose

Route

PO (tablet / chewable / granules)

PEDIATRIC DOSE

Age-specific (chewable / granules) — protocol-based only

Do not miss

Must-not-miss safety points

Major warning

- Neuropsychiatric effects (mood changes, agitation, depression, suicidal ideation) - NOT for acute asthma attack (no bronchodilator effect) - Should not replace inhaled corticosteroids in moderate–severe asthma - Use only when benefit clearly outweighs risk (especially mild disease)

Indications

Primary

  • Asthma (maintenance therapy; mild persistent or adjunct)
  • Allergic rhinitis

Secondary

  • Exercise-induced bronchoconstriction (prevention)

Dosing

STANDARD (ADULT PO)

Adult: 10 mg PO once daily (often evening); pediatrics: age-specific chewable/granules per protocol

ADULT DOSE

STANDARD (ADULT): - 10 mg once daily (usually evening)

PEDIATRIC DOSE

Age-specific dosing (chewable / granules) — protocol-based

MAX DOSE

Standard fixed dosing by age group / formulation per product labeling

Practical Note

- Once-daily dosing - Not for acute symptom relief or acute attack - Should not replace inhaled corticosteroids when moderate–severe asthma pathways require ICS

Warnings

Clinical warnings

  • Neuropsychiatric symptoms (mood, sleep, behavior changes; depression; suicidal ideation — vigilance across ages)
  • Headache, GI upset (common, less critical)
  • Rare hypersensitivity reactions

Contraindications

  • Known hypersensitivity

Drug interactions

  • Few major pharmacokinetic interactions typical at standard doses
  • Strong enzyme inducers (e.g., selected anticonvulsants, rifampin-class agents) may reduce montelukast exposure — relevance case-by-case

Special populations

Pediatrics

Age-specific (chewable / granules) — protocol-based only

Pregnancy

Pregnancy: - Use per risk–benefit assessment; follow current labeling and OB guidance Pediatrics: - Common use — counsel caregivers on behavior/mood/sleep changes; reassess after initiation or dose/formulation change

Lactation

Follow product labeling and specialist guidance

Renal impairment

No routine dose change emphasized for mild renal impairment in many references — severe renal impairment: follow labeling.

Hepatic impairment

Hepatic metabolism; severe hepatic impairment: follow labeling / specialist.

Elderly

Generally well tolerated; monitor for neuropsychiatric symptoms and drug benefit.

Administration

- Oral only (tablet / chewable / granules per age) - Once daily - Often given in evening

Monitoring

  • Monitor: - Asthma control / symptom response (ACT / clinic criteria per pathway) - Behavioral / mood / sleep changes
  • Recheck: - After initiation or formulation change - If inadequate asthma control at 48–72h on correct use → reassess as maintenance failure (not rescue escalation); do not continue blindly without ICS/step-up review per guideline
  • Hold / reassess: - Neuropsychiatric symptoms - No demonstrable clinical benefit

Overdose / toxicity

Clinical Picture

Usually mild (drowsiness, thirst, headache, agitation)

Immediate Actions

Stop drug Supportive care

Antidote

None

Decontamination

Acute large ingestion: poison center; supportive care.

Escalation

Severe agitation, self-harm ideation, or neurologic decline → emergency mental health / ED pathways.

Clinical pearls

Common mistakes, resistance logic, and bedside traps

High-Yield

  • Not a rescue medication
  • Consider mainly as adjunct or when inhaled therapy not tolerated / additive rhinitis–asthma benefit

Clinical

  • Useful for exercise-induced bronchoconstriction prevention when pathway-appropriate

Safety

  • Stop and reassess if behavioral or mood changes occur

Pharmacy Tool

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Montelukast 5 mg/mL oral suspension

suspension · oral

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Pharmacokinetics

- Oral absorption - Hepatic metabolism

Mechanism of action

- Leukotriene receptor blockade → reduced airway inflammation (leukotriene pathway)

Common brand names

Saudi Arabia

Singulair, Montair

Global

Montelukast, (placeholder — verify local formulation)

Common trade names are curated examples only — formulations and availability vary. Verify the exact product name with your local pharmacy and national regulator before prescribing or dispensing.

Country practice notes

Global data (no country-specific data available)

  • Follow local antimicrobial stewardship policy, hospital formulary, and national resistance guidance.
  • Confirm dosing, stock, and restrictions with institutional pharmacy and current product labeling.

References

Saudi Arabia

  • SFDA (Saudi Food & Drug Authority)
  • Saudi National Formulary / MOH (where available)

International

  • WHO Model List of Essential Medicines (verify current edition)
  • US FDA or EU EMA product information (when national SmPC is unavailable)
  • GINA asthma strategy (maintenance vs reliever distinction)
  • FDA / regulatory neuropsychiatric safety communications (montelukast)
  • Product labeling (age formulations, max daily dose)