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Zafirlukast oral

Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.





This medication is used for the prevention and treatment of chronic asthma. It is not intended for acute attacks.



This drug may also be used to minimize breathing problems caused by exercising or sensitivity to aspirin.

How To Use

Take as directed twice daily one hour before or two hours after a meal on a regular basis. While the drug should continue to be taken during an asthma attack, it will not stop the attack. It is meant to lessen the number and severity of attacks.

Side Effects

Headache, nausea and diarrhea may occur. If these continue or are bothersome, notify your doctor promptly. Rarely, serious liver disease may occur. If you notice any of the following highly unlikely but very serious side effects, seek immediate medical attention: persistent nausea, stomach pain, dark urine, fatigue, yellowing eyes or skin. If you experience any of the side effects mentioned above, use of this drug may need to be stopped. If treatment is stopped due to those effects, never take this drug again. There is an increased risk of liver problems occurring in females. Very unlikely but notify your doctor promptly if you develop: sore throat, bleeding, bruising, muscle aches, unusual weight loss. An allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of an allergic reaction include: rash, itching, swelling, dizziness, trouble breathing. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor your medical history, especially of: liver problems, any allergies. Caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug. Tell your doctor if you are pregnant before taking this medication. This medication is present in breast milk. Avoid this drug while breast-feeding.

Drug Interactions

Tell your doctor of all nonprescription or prescription medication you may take especially of: terfenadine, astemizole, warfarin, aspirin, erythromycin, theophylline. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include rash or severe upset stomach.


Do not share this medication with others. Laboratory and/or medical tests (e.g., liver function) should be performed to monitor your progress and possible side effects.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.


Store at room temperature between 68 and 77 degrees F (20-25 degrees C) away from light and moisture.

Medical Alert

Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA), or 1-800-668-1507 (Canada).