zafirlukast

Do not use zafirlukast to treat an asthma attack that has already begun. It will not work fast enough to reverse your symptoms. Use only a fast-acting inhalation medication to treat an asthma attack. Talk with your doctor if any of your asthma medications do not seem to work as well in treating or preventing asthma attacks.

It may take up to several weeks of using this medicine before your symptoms improve. For best results, keep using the medication as directed. Talk with your doctor if your symptoms do not improve after several weeks of treatment.

Call your doctor right away if you feel that this medicine is not working as well as usual, or if it makes your condition worse. If it seems like you need to use more of any of your medications in a 24-hour period, talk with your doctor.

Zafirlukast is a leukotriene (loo-koe-TRY-een) inhibitor. Leukotrienes are chemicals your body releases when you breathe in an allergen (such as pollen). These chemicals cause swelling in your lungs and tightening of the muscles around your airways, which can result in asthma symptoms.

Zafirlukast is used to treat and prevent asthma attacks in adults and children as young as 5 years old.

Do not give this medication to a child without a doctor's advice.

Zafirlukast may also be used for other purposes not listed in this medication guide.

Do not use this medication if you are allergic to zafirlukast.

Before using zafirlukast, tell your doctor if you are allergic to any drugs (especially aspirin), or if you have liver disease. You may not be able to use zafirlukast, or you may need dosage adjustments or special tests during treatment.

The chewable tablet form of this medication may contain up to 0.842 milligrams of phenylalanine. Talk to your doctor before using this form of zafirlukast if you have phenylketonuria (PKU).

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Zafirlukast can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.

Zafirlukast is usually taken once daily in the evening for prevention of asthma or allergy symptoms. Follow your doctor's instructions.

Take zafirlukast on an empty stomach, at least 1 hour before or 2 hours after a meal.

Do not use zafirlukast to treat an asthma attack that has already begun. It will not work fast enough to reverse your symptoms. Use only a fast-acting inhalation medication to treat an asthma attack. Talk with your doctor if any of your asthma medications do not seem to work as well in treating or preventing asthma attacks.

For best results, keep using zafirlukast as directed. Talk with your doctor if your symptoms do not improve after several weeks of treatment.

Asthma is often treated with a combination of different drugs. To best treat your condition, use all of your medications as directed by your doctor. Be sure to read the medication guide or patient instructions provided with each of your medications. Do not change your doses or medication schedule without advice from your doctor, even if you have no asthma symptoms.

Call your doctor right away if you feel that this medicine is not working as well as usual, or if it makes your condition worse. If it seems like you need to use more of any of your medications in a 24-hour period, talk with your doctor.

Store zafirlukast at room temperature away from moisture and heat.

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include skin rash and upset stomach.

Follow your doctor's instructions about any restrictions on food, beverages, or activity while you are using zafirlukast.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

• worsening asthma symptoms;
• skin rash, bruising, severe tingling, numbness, pain, muscle weakness; or
• nausea, stomach pain, loss of appetite, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

• headache;
• nausea, vomiting, diarrhea, stomach pain;
• weakness;
• dizziness;
• muscle pain; or
• fever, sore throat, cold symptoms.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

Before using zafirlukast, tell your doctor if you are using any of the following drugs:

• aspirin;
• a blood thinner such as warfarin (Coumadin);
• tolbutamide (Orinase);
• erythromycin (E.E.S., E-Mycin, Ery-Tab, Erythrocin);
• theophylline (Elixophyllin, Respbid, Slo-Bid, TheoDur, and others);
• carbamazepine (Carbatrol, Tegretol); or
• phenytoin (Dilantin).

This list is not complete and there may be other drugs that can interact with zafirlukast. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Your pharmacist can provide more information about zafirlukast.