zileuton (generic name)

Zyflo (brand name)

It is used to treat asthma
(zye LOO ton)
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What is this medicine?

ZILEUTON (zye LOO ton) is used to treat asthma. It helps to decrease the symptoms of asthma. Do not use for an acute asthma attack.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
  • if you frequently drink alcohol containing drinks
  • fever or infection
  • liver disease
  • an unusual or allergic reaction to zileuton, other medicines, foods, dyes, or preservatives
  • pregnant or trying to get pregnant
  • breast-feeding

How should I use this medicine?

Take this medicine by mouth with a glass of water. Follow the directions on your prescription label. Take your doses at regular intervals. This medicine may be taken with meals and at bedtime. For ease of swallowing, the tablets may be taken whole or split in half. Do not take your medicine more often than directed. Do not stop taking except on your doctor's advice.

Talk to your pediatrician regarding the use of this medicine in children. While this medicine has been used in children as young as 12 years of age, precautions do apply.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medicine?

  • alosetron
  • astemizole
  • caffeine
  • cisapride
  • cyclosporine
  • pimozide
  • propranolol
  • tacrine
  • terfenadine
  • theophylline or aminophylline
  • warfarin

What should I watch for while using this medicine?

Visit your doctor or health care professional for regular checks on your progress. Because this drug may affect liver function, you will receive regular blood tests to check your liver enzymes.

It may take a few weeks to notice the full benefit of this medicine. Tell your doctor or health care professional if your asthma symptoms do not improve. Take this medicine even when you do not have any asthma symptoms. Feeling well is a sign the medicine is working to control your asthma. Do not stop taking your medicine unless your doctor tells you to.

Talk to your doctor about what to do if you have an acute asthma attack. This medicine does not treat an acute attack. Always have your inhaled rescue medicine for asthma attacks with you.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
  • allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
  • breathing problems
  • dark urine
  • fever
  • flu-like symptoms (chills, fatigue, fever, muscle aches)
  • hallucinations
  • suicidal thoughts or other mood changes
  • trouble sleeping
  • unusually weak or tired
  • yellowing of the skin or eyes

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

  • abdominal pain
  • dizziness
  • headache
  • nausea
  • stomach upset

Where should I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Protect from light. Throw away any unused medicine after the expiration date.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Last Updated: April 28, 2010
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