Used to help prevent asthma attacks and for long-term treatment of asthma.
There may be other brand names for this medicine.
When This Medicine Should Not Be Used
You should not use this medicine if you have had an allergic reaction to zafirlukast, or if you are breastfeeding. Do not use this medicine if you have liver disease (including cirrhosis).
How to Use This Medicine
- Your doctor will tell you how much of this medicine to use and how often. Do not use more medicine or use it more often than your doctor tells you to.
- Take this medicine on an empty stomach at least 1 hour before or 2 hours after a meal.
- This medicine comes with patient instructions. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions.
If a dose is missed:
- If you miss a dose or forget to use your medicine, use it as soon as you can. If it is almost time for your next dose, wait until then to use the medicine and skip the missed dose. Do not use extra medicine to make up for a missed dose.
How to Store and Dispose of This Medicine
- Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
- Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
- Keep all medicine away from children and never share your medicine with anyone.
Drugs and Foods to Avoid
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
- Make sure your doctor knows if you are also taking aspirin, erythromycin (Eryc®, Ery-tab®, PCE®), theophylline (Elixophyllin®, Theo-24®, Theochron®, Theolair?, Uniphyl®), or a blood thinner (such as warfarin, Coumadin®, or Jantoven®).
Warnings While Using This Medicine
- Make sure your doctor knows if you are pregnant, planning to become pregnant, or if you have a rare blood condition called Churg-Strauss syndrome.
- This medicine helps prevent asthma attacks. For the medicine to work, you will need to take it on a regular schedule, even when you are not having problems with your asthma. If your asthma does not get better or if it gets worse while you or your child are taking this medicine, tell your doctor.
- This medicine will not stop an asthma attack that has already started. Your doctor may prescribe another medicine for you to use in case of an acute asthma attack.
- If you use any type of corticosteroid medicine to control your asthma, keep using it as ordered by your doctor. This includes corticosteroid medicines that are taken by mouth or inhaled (such as cortisone, prednisone, Azmacort®, Celestone®, Cortone®, Deltasone®, Flovent®, Prelone® Pediapred®, Vanceril®).
- If any of your asthma medicines do not seem to be working as well as usual, call your doctor right away. Do not change your doses or stop using your medicines without asking your doctor.
- Stop using this medicine and check with your doctor right away if you or your child have pain or tenderness in the upper stomach; pale stools; dark urine; loss of appetite; nausea; unusual tiredness or weakness; or yellow eyes or skin. These could be symptoms of a serious liver problem.
- This medicine may cause a rare blood condition called Churg-Strauss syndrome. This usually occurs in patients who have asthma or are taking oral steroid medicines that is being stopped or the dose is being reduced or lowered. Tell your doctor right away if you or your child have the following symptoms: a feeling of pins and needles, flu-like symptoms, numbness of the arms or legs, rash, or pain and swelling of the sinuses.
- This medicine may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed and have problems with sleep. If you, your child, or your caregiver notice any of these side effects, tell your doctor or your child's doctor right away.
- If your symptoms do not improve or if they get worse, call your doctor.
- Your doctor will need to check your progress at regular visits while you are using this medicine. Be sure to keep all appointments. Blood tests may be needed to check for unwanted effects.
Possible Side Effects While Using This Medicine
Call your doctor right away if you notice any of these side effects:
- Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
- Numbness in your arms or legs.
- Redness, warmth, or itching of the skin.
- Restlessness, anxiety, feeling irritable, mood or behavior changes, or thoughts of hurting yourself or others.
- Right-sided stomach pain, nausea, tiredness, or loss of appetite.
- Unexplained fever and chills.
- Unusual dreams or trouble with sleeping.
- Worsening of asthma symptoms (such as increased wheezing, trouble breathing, or tightness in the chest).
- Yellowing of your skin or the whites of your eyes.
If you notice these less serious side effects, talk with your doctor:
- Back, joint, or muscle pain.
- Headache or dizziness.
- Mild nausea, vomiting, diarrhea, or upset stomach.