II. Mechanism

  1. Leukotriene Antagonists attenuate bronchoconstriction and inflammation
  2. Leukotriene Receptor Antagonists (competitive inhibitor at D4 and E4 receptors)
    1. Zafirlukast (Accolate)
    2. Montelukast (Singulair)
  3. Leukotriene Synthesis Inhibitor (inhibits 5-lipoxygenase)
    1. Zileuton (Zyflo)

IV. Dosing: Zafirlukast (Accolate)

  1. Leukotriene Receptor Antagonist
  2. Avoid at mealtime
    1. Take 1 hour before or 2 hours after meals
  3. Dose
    1. Age >11 years old: 20 mg orally twice daily
    2. Child 7-11 years old: 10 mg orally twice daily

V. Dosing: Montelukast (Singulair)

  1. Leukotriene Receptor Antagonist
  2. Dose
    1. Adults: 10 mg orally at bedtime
    2. Child age 6 to 14 years: 5 mg orally at bedtime
    3. Child age 2-5 years: 4 mg orally at bedtime

VI. Dosing: Zileuton (Zyflo)

  1. Leukotriene Synthesis Inhibitor
  2. Indicated only in age 12 and over, and then only as adjunct in Severe Asthma
  3. Dosing
    1. Dose: 1200 mg orally two times daily
  4. Risks
    1. Greater adverse effects than other Leukotriene Modifiers
      1. Other agents are preferred (Zafirlukast, Montelukast)
    2. Hepatotoxicity in 5% (Monitor liver enzymes q3 months)

VII. Efficacy

  1. Modestly effective for maintenance management
  2. Inhaled Steroids are preferred over Leukotriene agents
  3. Used as adjunctive therapy in Asthma
  4. Benefit may be limited to patients with the 5-LO and LTC4 polymorphisms
    1. Sampson (2004) RT J Respir Care Practitioners 17:30-2 [PubMed]
    2. Wechsler (2005) Am J Respir Crit Care Med 172(1): 12-8 [PubMed]

VIII. Adverse Effects

  1. Montelukast is associated with increased risk of Major Depression and Suicide
    1. Black box warning as of 2020
    2. https://www.fda.gov/news-events/press-announcements/fda-requires-stronger-warning-about-risk-neuropsychiatric-events-associated-asthma-and-allergy
  2. Neurologic
    1. Agitation, irritability or aggression
    2. Anxiousness or restlessness
    3. Depressed mood
    4. Headache
    5. Insomnia
    6. Hallucinations
    7. Tremor
  3. Hepatotoxicity
    1. Zileuton (Zyflo)
    2. May occur with Zafirlukast (Accolate)
  4. Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome, EGPA)
    1. Associated with stopping Corticosteroids abruptly while starting Leukotriene Antagonists (Zafirlukast, Montelukast)
    2. Presenting findings
      1. Systemic Eosinophilic Vasculitis
      2. Vasculitic rash
      3. Pulmonary and cardiac conditions

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