Asthma Management with Leukotriene Modifiers

Introduction to Leukotriene Modifiers

• The American Academy of Allergy, Asthma, and Immunology recommends liver function monitoring when using zileuton, as approximately 4.4% of patients experience elevations in ALT levels to ≥3 times the upper limit of normal 1
• Zileuton is not recommended for use in children under 12 years of age due to lack of safety data, as stated by the American Academy of Pediatrics 2

Safety and Monitoring

• The majority of liver enzyme elevations (64.2%) occur within the first 3 months of treatment, but monitoring should continue throughout therapy, according to the American College of Chest Physicians 1
• Baseline liver function tests are required before initiating zileuton therapy, and monthly monitoring is necessary for the first 3 months, with periodic monitoring thereafter, as recommended by the National Asthma Education and Prevention Program 1
• Discontinuation of zileuton is recommended if ALT levels exceed 5 times the upper limit of normal, as suggested by the American Association for the Study of Liver Diseases 1
• The FDA recommends monitoring for neuropsychiatric events, including behavior/mood changes, when using montelukast 3
• Regular liver function monitoring is essential when using zileuton 4

Therapy Guidelines

• Zileuton should be considered primarily as an alternative adjunctive therapy for adults with persistent asthma who cannot use or do not respond adequately to other therapies, as stated by the American College of Allergy, Asthma, and Immunology 1
• Inhaled corticosteroids are the preferred treatment for initiating therapy in persistent asthma, according to the National Asthma Education and Prevention Program 1
• LTRAs are particularly considered for patients with poor inhaler technique or adherence issues with ICS, coexisting allergic rhinitis, exercise-induced bronchoconstriction, or aspirin-sensitive asthma 3
• Inhaled corticosteroids remain more effective than LTRAs for most patients with persistent asthma, and LTRAs should not be used as monotherapy in severe persistent asthma 3

Dosing and Administration

• The standard dosing of zileuton immediate-release is 600 mg four times daily, as recommended by the American Academy of Family Physicians 5
• Zileuton should not be used as monotherapy for long-term control of asthma, and guidelines clearly state that inhaled corticosteroids are the preferred treatment, as stated by the American College of Allergy, Asthma, and Immunology 1
• Montelukast (Singulair) is recommended as the first choice alternative for patients older than one year, with once-daily dosing and high compliance rates, as recommended by the American Academy of Family Physicians 5
• Zafirlukast (Accolate) is an alternative for patients seven years and older, with twice-daily dosing 5

Treatment Options for Asthma

Contraindications and Interactions

• Zileuton requires dose adjustment with concomitant medications metabolized by the liver, and potential interactions with hepatically cleared medications such as theophylline should be considered, as recommended by the American College of Clinical Pharmacy 1
• LTRAs offer several advantages over theophylline, including no need for serum concentration monitoring, a wider therapeutic window, fewer drug interactions, and a lower risk of adverse effects 5, 1
• Assess response to LTRAs after 4-6 weeks, and consider alternative therapy if no clear benefit is observed 3