montelukast

Antagonizes the effects of leukotrienes, which mediate the following:
- Airway edema,
- Smooth muscle constriction,
- Altered cellular activity.
Result is decreased inflammatory process, which is part of asthma and allergic rhinitis.

Therapeutic effects:

Decreased frequency and severity of acute asthma attacks.
Decreased severity of allergic rhinitis.
Decreased attacks of exercise-induced bronchoconstriction.

Pharmacokinetics ⬆ ⬇

Absorption: Rapidly absorbed (63–73%) following oral administration.

Distribution: Minimally distributed to tissues.

Protein Binding: 99%.

Metabolism/Excretion: Mostly metabolized by the liver by the CYP3A4 and CYP2C9 isoenzymes; metabolites eliminated in feces via bile; negligible renal excretion.

Half-Life: 2.7–5.5 hr.

Time/Action Profile ⬆ ⬇

(improved symptoms of asthma)

ROUTE	ONSET	PEAK‡	DURATION
PO (swallow)	within 24 hr	3–4 hr	24 hr
PO (chew)	within 24 hr	2–2.5 hr	24 hr

‡Plasma concentrations.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Acute attacks of asthma.

Use Cautiously in:

Phenylketonuria (chewable tablets contain aspartame);
Hepatic impairment (may need to ↓ dose);
Reduction of corticosteroid therapy (may ↑ risk of eosinophilic conditions);
Pedi: Children <6 yr (exercise-induced bronchoconstriction), <2 yr (seasonal allergic rhinitis), <12 mo (asthma), <6 mo (perennial allergic rhinitis) (safety and effectiveness not established).

Adv. Reactions/Side Effects ⬆ ⬇

Derm: rash, STEVENS-JOHNSON SYNDROME (SJS), TOXIC EPIDERMAL NECROLYSIS (TEN)

EENT: epistaxis, otitis (children), rhinorrhea, sinusitis(children)

GI: ↑liver enzymes, abdominal pain, diarrhea(children), dyspepsia, nausea(children)

Neuro: aggression, agitation, anxiety, attention disturbance, depression, disorientation, dream abnormalities, fatigue, hallucinations, headache, insomnia, irritability, memory impairment, obsessive-compulsive symptoms, restlessness, sleep walking, stuttering, SUICIDAL THOUGHTS/BEHAVIORS, tics, tremor, weakness

Resp: cough

Misc: EOSINOPHILIC CONDITIONS (INCLUDING CHURG-STRAUSS SYNDROME), fever

Interactions ⬆ ⬇

Drug-drug:

CYP3A4 inducers and CYP2C9 inducers, including phenobarbital and rifampin, may ↓ levels and effectiveness.

Route/Dosage ⬆ ⬇

Asthma

PO (Adults and Children ≥15 yr): 10 mg once daily.
PO (Children 6–14 yr): Chewable tablets: 5 mg once daily.
PO (Children 2–5 yr): Chewable tablets or granules: 4 mg once daily.
PO (Children 12–23 mo): Granules: 4 mg once daily.

Exercise-Induced Bronchoconstriction

PO (Adults and Children ≥15 yr): 10 mg ≥2 hr before exercise. Do not take within 24 hr of another dose; if taking daily doses, do not take dose for exercise-induced bronchoconstriction.
PO (Children 6–14 yr): Chewable tablets: 5 mg ≥2 hr before exercise. Do not take within 24 hr of another dose; if taking daily doses, do not take dose for exercise-induced bronchoconstriction.

Allergic Rhinitis

PO (Adults and Children ≥15 yr): Seasonal or perennial: 10 mg once daily.
PO (Children 6–14 yr): Seasonal or perennial: 5 mg once daily (as chewable tablet).
PO (Children 2–5 yr): Seasonal or perennial: 4 mg once daily (as chewable tablet or granules).
PO (Children 6–23 mo): Perennial only: 4 mg once daily (as granules).

Availability ⬆ ⬇

(Generic available)

Tablets: 10 mg
Chewable tablets cherry flavor: 4 mg; 5 mg
Oral granules: 4 mg/pkt

Assessment ⬆ ⬇

Assess lung sounds and respiratory function prior to and periodically during therapy.
Assess allergy symptoms (rhinitis, conjunctivitis, hives) before and periodically during therapy.
Monitor closely for changes in behavior or new neuropsychiatric symptoms that could indicate the emergence or worsening of depression or suicidal thoughts. If observed, discontinue use and contact health care provider immediately.

Lab Test Considerations:

May ↑ AST and ALT.

Implementation ⬆ ⬇

Doses of inhaled corticosteroids may be gradually ↓ with supervision of health care provider; do not discontinue abruptly.
PO: For asthma, administer once daily in the evening. For allergic rhinitis, may be administered at any time of day.
- Administer granules directly into mouth; mix in a spoonful of cold or room-temperature foods (use only applesauce, mashed carrots, rice, or ice cream) or dissolved in 5 mL of cold or room-temperature baby formula or breast milk. Do not open packet until ready to use. After opening packet, administer full dose within 15 min. Do not store mixture. Discard unused portion. Do not dissolve granules in fluid, but fluid may be taken following administration. Granules may be administered without regard to meals.
- For Exercise-Induced Bronchoconstriction: Administer one tablet ≥2 hr before exercise; do not take within 24 hr of another dose.

Patient/Family Teaching ⬆ ⬇

Explain the purpose and side effects of the medication to the patient. Instruct patient to take medication as directed daily in the evening or ≥2 hr before exercise, even if not experiencing symptoms of asthma. If dose is missed, omit and take next dose at regularly scheduled time; do not double doses. Do not discontinue therapy without consulting health care provider. Advise patient to read Patient Information before starting therapy and with each Rx refill in case of changes.
Instruct patient not to discontinue or ↓ dose of other asthma medications without consulting health care provider.
Advise patient that montelukast is not used to treat acute asthma attacks but may be continued during an acute exacerbation. Patient should carry rapid-acting therapy for bronchospasm at all times. Advise patient to notify health care provider if more than the maximum number of short-acting bronchodilator treatments prescribed for a 24-hr period are needed.
Advise patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care provider before taking any new medications.
Encourage patient and family to be alert for emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, impulsivity, akathisia, hypomania, mania, worsening of depression, and suicidal ideation, especially during early antidepressant therapy. Assess symptoms on a day-to-day basis as changes may be abrupt. If these symptoms or rash occurs, notify health care provider.
Rep: Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or if breastfeeding.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇