If clinical signs and/or symptoms of liver dysfunction develop (eg, right upper quadrant pain, nausea, fatigue, lethargy, pruritus, jaundice, or “flu-like” symptoms) or transaminase elevations

5 times the upper limit of normal occur, discontinue ZYFLO CR
® and follow hepatic function enzymes until normal. Use with caution in patients who consume substantial quantities of alcohol and/or have a history of liver disease.
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.