Onset of Churg-Strauss syndrome (CSS), a rare but potentially life-threatening condition, is probably not specifically associated with the drug montelukast but may be associated with medications for long-term control of severe asthma, researchers conclude.
Their study, published early online in Thorax, explored the relationship between montelukast and the onset CSS, a type of small-vessel vasculitis.
It follows concerns that the condition might be precipitated by the drug.
The researchers retraced the medication histories of 78 CSS patients from France and Germany and compared exposures to montelukast and other asthma medications during the three-month “index” period immediately preceding CSS onset with those of four previous three-month “control” periods.
Montelukast exposure during control periods increased over three consecutive calendar periods of CSS onset from 1999 to 2003.
The researchers note from these findings that although montelukast was associated with a more than fourfold higher risk of CSS onset within three months, estimates obtained for 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.