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Medication Detail

image of medication detailed on this page

Medication Type

Long Term Control, should be taken every day as prescribed

Generic Names


Brand Names

Zyflo®, Zyflo CR®


This medication is a daily medication for controlling asthma symptoms. It works over time by decreasing the body’s response to allergens.


Oral tablet, oral extended release tablet


Adults and children ≥ 12 years
  • Immediate-release tablets: one 600 mg tablet four times a day
  • Extended-release tablets: two 600 mg tablets twice daily, with morning and evening meals

Proper Use

  • Immediate-release tablet may be taken with or without food.
  • Extended release tablet should be taken within 1 hour after morning and evening meals.
  • Do not chew, cut, or crush extended-release tablet.


  • Do NOT use this drug to treat an asthma attack.
  • Avoid drinking large amounts of alcohol while on this medication.
  • Zileuton is excreted in breast milk and should not be used while breastfeeding.
  • Zileuton should not be used in patients with liver disease.

Common Interactions

This medication interacts with theophylline, warfarin, propranolol and other less common medications.

Tell your doctor and pharmacist about all of your medications and health problems so they can check for any interactions.

Possible Side Effects

Possible side effects include headache, upset stomach, nausea, muscle pain, and dizziness.

Tell your doctor or seek medical attention if you notice any signs of an allergic reaction (rash, hives, wheezing, tightness in the chest or throat, trouble breathing or swelling of the face), have dark colored urine or light colored stools, symptoms of depression, chest pain, or difficulty sleeping.

Proper Storage

  • Store at room temperature.
  • Protect from heat, light, and water.
  • Do not store in a bathroom or kitchen.

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