Montelukast and risk of Churg-Strauss syndrome

[News Feeder14]

A study published early online in Thorax has explored the relationship between montelukast and the onset of Churg-Strauss syndrome (CSS), a rare small-vessel vasculitis that is potentially life-threatening. This follows concerns that this condition might be precipitated by the drug.

Researchers retraced the medication histories of 78 CSS patients from France and Germany and compared exposures to montelukast and other asthma medications during the 3-month 'index' period immediately preceding CSS onset with those of 4 previous 3-month 'control' periods. The odds ratio (OR + 95% CI) for CSS onset were as follows:

• 4.5 (1.5 to 13.9) for montelukast
• 3.0 (0.8 to 10.5) for inhaled long-acting beta2-agonists
• 1.7 (0.5 to 5.4) for inhaled corticosteroids
• 4.0 (1.3 to 12.5) for oral corticosteroids

Montelukast exposure during control periods increased over 3 consecutive calendar periods of CSS onset from 1999 to 2003 (p for trend = <0.0001).

The researchers note from these findings that though montelukast was associated with over a 4 fold higher risk of CSS onset within 3 months, the estimates obtained for the other asthma medicines (though only statistically significant for oral corticosteroids) examined suggest that “this link is confounded by a general escalation of asthma therapy before CSS onset” and the montelukast-CSS association observed is also likely to be explained by its increasing use over time.” They conclude “taken together, these findings might suggest that the association with CSS onset is not specific to montelukast but a phenomenon possibly associated with the group of medications prescribed for long-term control of severe asthma.”
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