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Leukotriene modifiers: Nursing Pharmacology

Notes

Notes

LEUKOTRIENE MODIFIERS
DRUG NAME
montelukast (Singulair), zafirlukast (Accolate)
zileuton
CLASS
Leukotriene receptor antagonists
Leukotriene synthesis inhibitor
MECHANISM OF ACTION
Bind to and block leukotriene receptors in smooth muscle cells of the airways
Inhibits leukotriene production
INDICATIONS
  • Asthma prophylaxis; especially effective in preventing exercise-induced asthma
  • Zafirlukast: aspirin-induced asthma
  • Montelukast: allergic rhinitis
  • Asthma prophylaxis; especially effective in preventing exercise- or aspirin-induced asthma
ROUTE(S) OF ADMINISTRATION
PO
SIDE EFFECTS
  • Headache
  • Gastrointestinal disturbances
  • Fatigue
  • Skin rash or urticaria
  • Severe allergic reactions
  • Zafirlukast and zileuton: hepatotoxicity
  • Boxed warning for montelukast: agitation, depression, sleep disturbances, and suicidal ideation
CONTRAINDICATIONS AND CAUTIONS
  • Acute asthma attacks
  • Zafirlukast: liver disease
  • Acute asthma attacks
  • Suicidal ideation
  • Liver disease
NURSING CONSIDERATIONS
Assessment and monitoring
  • Respiratory status
  • Liver function
  • Mental status

Client education
  • Do not use for acute asthma attacks
  • Take montelukast two hours before exercise if prescribed for exercised induced bronchoconstriction
    • Oral granules: take within 15 minutes of opening packet
    • Can be taken directly or with a tablespoon of applesauce or ice cream
  • Take zafirlukast on an empty stomach
  • Take zileuton with food
  • Report symptoms of hepatotoxicity, neuropsychiatric problems
  • Continue taking as prescribed even in absence of symptoms
Transcript

Leukotriene modifiers are a group of medications that help breathing, so they are typically used to manage nasal congestion and inflammation associated with allergic rhinitis, as well as to manage narrowing and obstruction of the airways in obstructive lung diseases, such as asthma.

Asthma is characterized by chronic inflammation in the lungs, as well as asthma exacerbations or attacks, where certain triggers, such as viruses, allergens, stress, aspirin and exercise, lead to reversible bronchial smooth muscle spasms and mucus production, both of which make it hard to breathe. As a result, clients experience symptoms like dyspnea, wheezing, coughing, and chest tightness.

Now, leukotriene modifiers act by decreasing the action of leukotrienes, which are inflammatory molecules produced and released by certain immune cells, such as mast cells, to trigger an inflammatory response.

Once released, leukotrienes bind to leukotriene receptors located on the bronchial smooth muscles, causing them to contract, as well as on the mucous glands to increase mucus secretion. In addition, leukotrienes increase blood vessel permeability, which results in fluid leakage and edema.

Now, leukotriene modifiers can be classified into two groups, based on their mechanism of action. On the one hand, leukotriene receptor antagonists, such as montelukast and zafirlukast, bind to and block leukotriene receptors on the airways, preventing leukotrienes from binding.

On the other hand, leukotriene synthesis inhibitors, such as zileuton, inhibit the enzyme that produces leukotrienes.

Now, regardless of the exact mechanism, the net effect is decreased leukotriene action, leading in turn to decreased smooth muscle contraction in the airways, decreased mucus secretion, and decreased inflammation.

Alright, now unlike other medications that are used for asthma, leukotriene modifiers are typically administered orally and have slower onset of action, which is why they are only used as part of maintenance therapy and not during an acute attack. In addition, they are especially effective in preventing exercise- or aspirin- induced asthma.

However, leukotriene modifiers can have side effects. The most common side effects are mild and nonspecific, such as a headache, gastrointestinal disturbances, fatigue, and a skin rash or urticaria.

However, they can also lead to severe allergic reactions as well as neuropsychiatric effects like agitation, sleep disturbances, depression, and suicidal ideation.

Montelukast has a boxed warning for these neuropsychiatric events. In general, leukotriene modifiers should be used with caution in those with severe asthma, as well as in clients with existing depression or suicidal ideation.

Zafirlukast and zileuton are also potentially hepatotoxic, and zafirlukast is contraindicated in clients with active liver disease.

OK, before administering a leukotriene modifier, assess your client’s respiratory status, and confirm your client’s liver function tests are normal. Also be sure the client does not have a history of depression or suicidal ideation.

Sources
  1. "Focus on Nursing Pharmacology" LWW (2019)
  2. "Pharmacology" Elsevier Health Sciences (2014)
  3. "Mosby's 2021 Nursing Drug Reference" Mosby (2020)
  4. "Saunders Comprehensive Review for the NCLEX-RN Examination" Saunders (2016)
  5. "Goodman and Gilman's The Pharmacological Basis of Therapeutics, 13th Edition" McGraw-Hill Education / Medical (2017)