Zyflo CR

Generic Name: Zileuton

  • What is Zyflo CR?

    Zyflo CR is used to prevent asthma attacks and for long-term management of asthma in adults and children ≥12 years of age. Zyflo CR is not a rescue medicine and should not be used if you need relief right away for an asthma attack.

  • What is the most important information I should know about Zyflo CR?

    Zyflo CR is not a bronchodilator and should not be used to relieve an asthma attack that has already started.

    The most serious side effect of Zyflo CR is potential elevation of liver enzymes and liver problems. While taking Zyflo CR, you must visit your doctor for liver enzyme tests on a regular basis.

    Some behavior changes and sleep difficulties may occur when you start Zyflo CR. Talk to your doctor right away if either one occurs.

  • Who should not take Zyflo CR?

    You should not use Zyflo CR if you ever had an allergic reaction to any of its ingredients. Do not use Zyflo CR if you have active liver disease or if repeated blood tests show elevated liver enzymes.

    Zyflo CR is not appropriate for children <12 years of age.

  • What should I tell my doctor before I take the first dose of Zyflo CR?

    Tell your doctor about all prescription, over-the-counter, and herbal medications you are taking before beginning treatment with Zyflo CR. Also, talk to your doctor about your complete medical history, especially if you have ever had liver problems, including hepatitis, jaundice (yellow eyes or skin), or dark urine; drink alcohol (tell your healthcare provider how much and how often you drink alcohol); have difficulty swallowing pills; are pregnant or planning to become pregnant; or you are breastfeeding.

  • What is the usual dosage?

    The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

    Adults and children ≥12 years: The usual dosage is two 600-milligram (mg) tablets two times daily, within 1 hour after your morning and evening meals, for a total daily dose of 2,400 mg.

  • How should I take Zyflo CR?

    Take Zyflo CR exactly as prescribed by your healthcare provider. Do not decrease the dose or stop taking the medicine without talking to your healthcare provider first, even if you have no asthma symptoms.

    Swallow Zyflo CR whole. Do not chew, cut, or crush the tablets. Tell your healthcare provider if you cannot swallow the tablets whole.

    Follow your healthcare provider's instructions for what to do if you get sudden symptoms of an asthma attack. You can continue taking Zyflo CR during asthma attacks. Keep taking your other asthma medicines as directed while taking Zyflo CR.

  • What should I avoid while taking Zyflo CR?

    Avoid chewing, cutting, or crushing Zyflo CR tablets.

    Do not miss any doctor's appointments and be sure to follow all instructions. Have blood tests done as ordered by your doctor to check your liver enzymes.

  • What are possible food and drug interactions associated with Zyflo CR?

    If Zyflo CR is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Zyflo CR with propranolol, theophylline, warfarin, or alcohol.

  • What are the possible side effects of Zyflo CR?

    Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this drug.

    Side effects may include: nose and throat irritation, sinusitis, upper respiratory infection, throat pain, headache, muscle aches, nausea, diarrhea

    Serious side effects include liver problems that may be associated with pain on the right side of your stomach area, nausea, tiredness, lack of energy, itching, yellow skin or yellow color in the whites of your eyes, dark urine, or flulike symptoms. Tell your doctor right away if you experience any of these symptoms.

  • Can I receive Zyflo CR if I am pregnant or breastfeeding?

    The effects of Zyflo CR during pregnancy and breastfeeding are unknown. This medication should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus. Tell your doctor immediately if you are pregnant, plan to become pregnant, or are breastfeeding.

  • What should I do if I miss a dose of Zyflo CR?

    If you miss a dose, take your next scheduled dose when it is due. Do not take two doses at once.

  • How should I store Zyflo CR?

    Store at room temperature, away from light.

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I'm Shereen A. Gharbia, PharmD. Welcome to PDR Health!

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