- ZYFLO CR® achieved a 21% improvement in FEV1 at 12 weeks (P=0.03)
- ZYFLO CR® achieved a 13% improvement in FEV1 at the first study time point of 2 weeks (P<0.01)
- ZYFLO CR® achieved a 44% increase in FEV1 volume at 12 weeks (P=0.02)
ZYFLO CR® significantly reduced use of SABA rescue therapy (n=199; P=0.009)2
ZYFLO CR
® is contraindicated in patients with active liver disease or transaminase elevations

3 times the upper limit of normal.
Please see Important Safety Information and full
Prescribing Information.
Important Safety Information
ZYFLO CR
® is a leukotriene synthesis inhibitor indicated for the prophylaxis and chronic treatment of asthma in adults and children 12 years of age and older. Do not use ZYFLO CR
® to treat an acute asthma attack.
ZYFLO CR
® is contraindicated for patients with active liver disease or persistent hepatic function enzyme elevations

3 times the upper limit of normal. Assessment of hepatic function enzymes prior to and during ZYFLO CR
® therapy should be undertaken. ZYFLO CR
® is also contraindicated for patients with a history of allergic reactions to zileuton or any of the other ingredients.
The active ingredient in ZYFLO CR
® increases theophylline, warfarin, and propranolol levels. Dose adjustment of these other drugs and patient monitoring may be required. ZYFLO CR
® should be used with caution in patients who consume substantial quantities of alcohol and/or have a history of liver disease. Neuropsychiatric events, including sleeping disorders and behavioral changes, may occur with ZYFLO CR
®.
The most common adverse reactions (
>5%) include: sinusitis, nausea, and pharyngolaryngeal pain.