Asthma

Montelukast

Pathophysiology

Trade Name

Indications

Mechanism of Action

Signs/Symptoms

Pharmacokinetics

Contraindications/Precautions

Adverse Reactions/Side Effects

Route/Dosage

Nursing Implications

Patient & Family Teaching

Singulair

Etiology

Allergic Asthma

Chest tightness

Cough

Shortness of breath

Airflow limitation on expiration

Wheezing

Binds to LTD4 receptors

prevents smooth muscle contraction of bronchial airways

an acute immune response

early-phase response

Chronic airway inflammation

late-phase response

immeiate and potent antigen-antibody reaction

prevention and chronic treatment of asthma

management of seasonal allergic rhinitis

reaction occurs on cells rich with histamines and leukotrienes (eg. mast cells)

prevention of exercise-induced bronchoconstriction (EIB)

Characterized by "attacks" - typically short and respond to medication

Age of onset ~50% before age 10, 80% before age 40

triggers mucosal swelling and bronchoconstriction

Many possible triggers: allergens, exercise, viral respiratory infection, air pollutants, drugs

rapidly absorbed following oral administration (63-73%)

Occurs 5-12 hours after initial response and can last several hours to days

mostly metabolized by the liver, eliminated in feces, via bile with negligible renal excretion

airways become sensitized/hyper-responsive

Treatment usually 2 types

Long-term symptom control

Rapid (acute) symptom control

distribution is unknown

Taken only when needed at the onset of an acute attack to alleviate symptoms

further episodes may be triggered by factors other than allergens (eg. cold, dust, pollution)

peak onset is within 24 hours

Taken on a regular schedule to help lessen and prevent symptoms

oral (chewed) peak onset 2-2.5 hours, duration 24 hours

neutrophils and eosinophils attract inflammatory mediators to create cycle of inflammation/obstruction

oral (swallowed) peak onset 3-4 hours, duration 24 hours

half-life is 2.7-5.5 hours

do not use if allergic

use cautiously in acute attacks of asthma, reduction of corticosteroids, Phenylketonuria

Can sensitize airways for future episodes of asthma attacks

use when pregnant/breastfeeding only if benefit to patient outweighs risk to infant

Route: PO

assessment: assess lung sounds prior to and periodically during therapy, assess for changes in behaviour related to suicidal thoughts or depression, assess for rash

headaches, nausea, diarrhea and nightmares, may cause liver dysfunction

Adult and children >15y/o dose: 10mg/day

Child 6-14 y/o: 5mg/day chew tab

implementation: may be gradually decreased with supervision, administer OD in the evening for asthma, or any time of day for allergic rhinitis; administer granules directly into mouth or mixed in soft foods (not fluids), administer dose within 15 minutes of opening, discard unused portion immediately. For EIB, take tablet 2+ hours before exercise, do not take within 24 hours of another dose

Child 2-5 y/o: 4mg/day chew tab

Child 12-23mo: 4mg/day packet of granules

For exercise-induced bronchoconstriction

this drug is for management of chronic symptoms, not to treat an acute attack

Adult/adolescent >15y/o: PO 10mg 2 hr prior to exercise. Do not take another dose w/i 24 hrs.

the medication is to help reduce the swelling of the lungs

should start seeing lessening symptoms in about a week

tablet needs to be chewed before swallowing

Avoid potentially hazardous activities, as dizziness may occur

fluid intake should be increased as possible

Justin Gillespie, Robyn Harris, & Lauren Van Rassel

Do not use for acute asthma attacks

Sealock, K., Lilley, L. L., Snyder, J. S., Collins, S. R., Seneviratne, C., & Lilley, L. L. (2021). Lilley's pharmacology for Canadian Health Care Practice. Elsevier.

If also taking OTC meds with ephedrine, do not consume alcohol

​​Skidmore-Roth, L. (2011). Mosby's 2011 Nursing Drug Reference (24th ed.). Mosby.

Vallerand, A. H., & Sanoski, C. A. (2021). Davis's drug guide for Nurses. F.A. Davis Company.

References: