Question 10. How safe are the anti-leukotrienes?
From Chapter 6 of the Philippine Consensus Report on Asthma 2004 by the Philippine College of Chest Physicians.
This guideline starts below.
How safe are the anti-leukotrienes?
Anti-leukotrienes (anti-LTs) are safe drugs even for prolonged use.
Summary of Evidence
The Antileukotriene Working Group has clearly established the safety of anti-LTs even when given for prolonged periods of time. An analysis of four 13-week RCTs of similar methodology assessing efficacy and safety of anti-LTs showed that of the 1484 asthmatics, 560 or 64% in the zafirlukast group and 391 (65%) in the placebo group developed adverse effects. In one of these studies, extended by Grossman to 39 more weeks, the most common adverse events noted were pharyngitis (zafirlukast and placebo 24.2%) and headache (zafirlukast, 13%; placebo 10.9%). A similar study assessing safety and tolerability of montelukast reported the same frequency of adverse reactions.
Anti-LTs should be used with caution among patients with liver disease, although more recent studies failed to implicate direct hepatotoxicity with leukotriene receptor antagonist use. Churg-Strauss syndrome, a rare severe eosinophilic granulomatous lung disease, has been reported to be associated with anti-LT use (1:20,000 asthma cases), noted particularly during the period of oral steroid tapering. It was proposed that this situation may be due to the unmasking, rather than causation, of Churg-Strauss syndrome. The syndrome may have mistakenly diagnosed as asthma and initially controlled with oral steroids. Once the oral steroid dose has decreased during tapering, then the syndrome resurfaced.« Previous Next »