Zafirlukast (By mouth)

There may be other brand names for this medicine.

You should not use this medicine if you have had an allergic reaction to zafirlukast, or if you are breastfeeding.

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.
Never share your medicine with anyone.

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.

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 leftover medicine after you have finished your treatment. You will also need to throw away old medicine after the expiration date has passed.
Keep all medicine away from children and never share your medicine with anyone.

Make sure your doctor knows if you are also taking aspirin, a blood thinner (such as warfarin, Coumadin®), or medicines to treat anxiety, asthma, arthritis, depression, diabetes, heart problems, high blood pressure, high cholesterol, infection, seizures, or stomach problems.
Tell your doctor if you are using medicines to treat HIV/AIDS (such as Crixivan®, Fortovase®, Invirase®, Retrovir®, Sustiva®, or Viracept®).

Make sure your doctor knows if you are pregnant, or if you have liver disease.
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 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.
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.

Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing.
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.
Tremors.
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.