Leukotrienes and asthma

CysLTs act as chemoattractants for eosinophils ^8–13:

• Enhance recruitment of inflammatory mediators
  In an ex vivo study of eosinophils from subjects with atopic asthma, CysLTs enhanced eosinophil recruitment.¹³
• Upregulate of adhesion molecules
  In an ex vivo study of blood eosinophils, LTD₄ upregulated the adhesive property of eosinophils.¹⁴
• Promote migration of eosinophils into airway
  In an ex vivo study of eosinophils from subjects with atopic asthma, CysLTs promoted migration of eosinophils.¹³
• Enhance survival of eosinophils
  When eosinophils isolated from subjects with atopic asthma were incubated with LTC₄ or LTD₄, their survival was significantly enhanced.¹¹

Characteristics of healthy bronchi are:

• Normal cellular activity
• Normal mucus secretion
• Intact epithelial layer
• Open airways

Leukotrienes mediate airway smooth muscle contraction and proliferation resulting in bronchoconstriction, as evidenced by airway narrowing.

• Bronchoconstriction can be initiated by triggers that include exercise, cold air, and allergens.¹⁵ Sensory nerve exposure can contribute to increased bronchial hyperreactivity manifested by cough or wheeze.

SELECTED SAFETY INFORMATION

• SINGULAIR should not be used as rescue medication to treat acute asthma attacks. Patients should be advised to have appropriate rescue medication available.
• Neuropsychiatric events have been reported in patients taking SINGULAIR. These events included agitation, aggressive behavior or hostility, anxiousness, depression, disorientation, dream abnormalities, hallucinations, insomnia, irritability, restlessness, somnambulism, suicidal thinking and behavior (including suicide), and tremor. The clinical details of some postmarketing reports appear consistent with a drug-induced effect. Patients should be advised to report any neuropsychiatric events.
• While the dose of inhaled corticosteroid may be reduced gradually under medical supervision, SINGULAIR should not be abruptly substituted for inhaled or oral corticosteroids.
• Patients receiving SINGULAIR should not decrease the dose or stop taking any other antiasthma medications unless instructed by a physician.
• The most common adverse reactions with an incidence >5% and greater than placebo in controlled clinical trials were upper respiratory infection, fever, headache, pharyngitis, cough, abdominal pain, diarrhea, otitis media, influenza, rhinorrhea, sinusitis, and otitis.
• Safety and effectiveness of SINGULAIR in patients younger than 12 months with asthma have not been established.

Please see Selected Safety Information about SINGULAIR.

Before prescribing SINGULAIR, please read the Prescribing Information.

See all references.

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