A simple blood test is needed before you start treatment with ZYFLO CR®

Liver function enzymes can increase while taking ZYFLO CR®. One study showed that liver enzymes increased in 1.8% of patients, but most people do not develop increased liver enzymes.

Your doctor will want to monitor your liver enzymes and watch for changes or elevations, a serious side effect of ZYFLO CR®. Liver enzymes can be measured by a simple blood test to report on how your liver is functioning.

Liver monitoring is recommended:
  • Before starting ZYFLO CR®
  • Once a month for the first 3 months
  • Every 2–3 months for the rest of the first year
  • Periodically thereafter while you remain on the drug
Getting started with Zyflo CR
ZYFLO CR® on Facebook cornerstone

Patient brochure


Download a PDF of the ZYFLO CR® patient brochure
  • Helps you identify the signs and symptoms of asthma
  • Provides important information about what to expect during treatment with                     ZYFLO CR®
  • Explains how to take ZYFLO CR®

*On co-pays up to $70. See savings card for details and instructions. Subject to availability. Restrictions apply.




Important Patient Safety Information


ZYFLO CR® is a medicine used to prevent asthma attacks and for long-term management of asthma in adults and children 12 years of age and older. ZYFLO CR® is not a rescue medicine and should not be used for immediate relief during an asthma attack.

You should not take ZYFLO CR® if you have active liver disease or repeated blood tests showing elevated liver enzymes. Your doctor may do blood tests to check your liver before you take ZYFLO CR® and while you are taking it. You should not take ZYFLO CR® if you have ever had an allergic reaction to ZYFLO CR® or any of its ingredients.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines. ZYFLO CR® and certain other medicines may affect each other causing side effects. Tell your doctor if you drink alcohol (how much and how often) and if you have ever had liver problems including hepatitis, jaundice (yellow eyes or skin), or dark urine.

 In addition, report any changes in your behavior or sleeping habits while taking
ZYFLO CR®.

Some of the most common side effects are nose and throat irritation, sinusitis, upper respiratory infection, throat pain, headache, muscle aches, nausea, and diarrhea.

For additional safety information, please see Patient Product Information.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.