Singulair

Action

Blocks action of leukotrienes, decreasing smooth muscle contractions and edema in bronchial airways and preventing inflammation and bronchospasm

Availability

Oral granules: 4-mg base/packet

Tablets: 10 mg

Tablets (chewable): 4 mg, 5 mg

Indications and dosages

➣ Long-term asthma management

Adults and children ages 15 and older: 10-mg tablet P.O. daily in evening

Children ages 6 to 14: 5-mg chewable tablet P.O. daily in evening

Children ages 2 to 5: 4-mg chewable tablet or one 4-mg packet oral granules P.O. daily in evening

Children ages 12 to 23 months: 4-mg packet oral granules P.O. daily in evening

➣ Prevention of exercise-induced bronchoconstriction (EIB)

Adults and children ages 15 and older: Single-dose, 10-mg tablet P.O. at least 2 hours before exercise; additional dose shouldn't be taken within 24 hours. Patients already taking 1 tablet daily for another indication shouldn't take an additional dose.

Children ages 6 to 14: 5-mg chewable tablet P.O. at least 2 hours before exercise; additional dose shouldn't be taken within 24 hours. Patients already taking 1 tablet daily for another indication shouldn't take an additional dose.

➣ Seasonal allergic rhinitis

Adults: 10 mg P.O. daily

Children ages 2 to 5: 4 mg P.O. daily either as either chewable tablet or packet of oral granules

➣ Perennial allergic rhinitis

Adults and children ages 15 and older: 10 mg tablet P. O. daily

Children ages 6 to 14: 5 mg P.O. daily as chewable tablet

Children ages 2 to 5: 4 mg P.O. daily as either chewable tablet or one 4-mg packet of oral granules

Children ages 6 to 23 months: 1 packet (4 mg) oral granules P.O. daily

Off-label use

• Chronic urticaria

Contraindications

• Hypersensitivity to drug or its components

Precautions

Use cautiously in:

• acute asthma attack, hepatic impairment, phenylketonuria

• pregnant or breastfeeding patients

• children younger than age 6 when used for EIB prevention (safety not established)

• children younger than age 2 when used for seasonal allergy (safety not established)

• children younger than age 1 when used for asthma (safety not established)

• children younger than age 6 months when used for perennial allergy (safety not established).

Administration

• Give with or without food.

• Administer oral granules either directly in mouth, dissolved in 1 teaspoon (5 mL) cold or room temperature baby formula or breast milk, or mixed with spoonful of cold or room temperature soft foods (applesauce, carrots, rice, or ice cream only). Don't open packet until ready to use. After opening packet, administer full dose (with or without mixing with baby formula, breast milk, or food); dose must be given within 15 minutes. If granules have been mixed with baby formula, breast milk, or food, don't store for future use.

• Ensure that patient taking drug for prevention of EIB has short-acting beta-agonist available for rescue.

Adverse reactions

CNS: fatigue, headache, dizziness, asthenia, agitation, aggressive behavior or hostility, anxiousness, depression, disorientation, dream abnormalities, hallucinations, insomnia, irritability, restlessness, somnambulism, tremor, suicidal thinking and behavior (including suicide)

EENT: nasal congestion, otitis and sinusitis (in children)

GI: abdominal pain; nausea and diarrhea (in children); dyspepsia; infectious gastroenteritis

Respiratory: cough

Skin: rash

Other: dental pain, influenza, fever

Interactions

Drug-drug. CYP450 inducers (such as phenobarbital, rifampin): decreased montelukast effects

Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase, eosinophils: increased levels

Patient monitoring

• Assess eosinophil count.

• Monitor temperature. Watch for fever and other signs and symptoms of infection.

See Monitor patient for change in mood or behavior, including suicidal ideation.

Patient teaching

• Advise patient (or caregiver) who has asthma or asthma and rhinitis to take drug in evening.

• Instruct patient (or caregiver) who has EIB not to take another dose within 24 hours of previous dose.

• Inform patient (or caregiver) that he may sprinkle granules onto soft foods (applesauce, carrots, rice, or ice cream only) and take immediately. Drug isn't intended to be dissolved in any liquid other than breast milk or baby formula. Don't store drug that has been mixed with food or liquids for future use.

• Instruct patient or caregiver that after opening packet of oral granules, dose must be taken within 15 minutes.

See Tell patient or caregiver that drug is for preventive use only, not for treatment of acute asthma attacks and that appropriate rescue medication should be available.

See Instruct patient or caregiver to notify prescriber if mood or behavior changes.

• Caution patient to avoid driving and other hazardous activities, because drug causes dizziness.

• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs and tests mentioned above.