side effects

Last reviewed 01/2018

  • most common side effects are headache and gastrointestinal disturbances

  • the long-term safety of these drugs has yet to be established

  • zafirlukast may cause raised transaminases. Rarely, liver function tests were consistent with drug-induced hepatitis which resolved on withdrawal of the drug. Zafirlukast should not be used in patients with cirrhosis or liver impairment

  • Churg-Strauss syndrome has occurred in patients taking zafirlukast and montelukast. In most of these cases the onset of the condition was associated with withdrawal of oral steroids and it is unclear whether the Churg-Strauss syndrome was a direct result of leukotriene antagonist therapy

  • in elderly patients taking zafirlukast, an increased incidence of respiratory tract infections has been noted. In children taking montelukast pharyngitis, sinusitis and influenza were more common than in patients taking placebo. Similarly in adults, influenza was more common in patients taking montelukast than placebo

Reference:

  • Ng J, Savage R, McQueen F. Churg-Strauss vasculitis syndrome and leukotriene receptor antagonists. . Ann Rheum Dis. 2005 Sep;64(9):1382
  • Wooltorton E.Asthma drug zafirlukast (Accolate): serious hepatic events. CMAJ. 2004 May 25;170(11):1668