Generic name: zafirlukast [ za-FIR-loo-kast ]
Brand name: Accolate
Dosage form: oral tablet (10 mg; 20 mg)
Drug class: Leukotriene modifiers

Medically reviewed by Drugs.com on May 31, 2024. Written by Cerner Multum.

What is zafirlukast?

Zafirlukast is a leukotriene (loo-koe-TRY-een) inhibitor that is used to prevent asthma attacks in adults and children as young as 5 years old.

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

Zafirlukast side effects

Get emergency medical help if you have signs of an allergic reaction: hives, blisters, severe itching; difficult breathing; swelling of your face, lips, tongue, or throat.

Tell your doctor right away if you have signs of blood vessel inflammation: flu-like symptoms, severe sinus pain, a skin rash, numbness or a "pins and needles" feeling in your arms or legs.

Some people using zafirlukast have had new or worsening mental problems. Stop taking zafirlukast and call your doctor right away if you have unusual changes in mood or behavior, such as:

• agitation, aggression, feeling restless or irritable;

• anxiety, depression, confusion, problems with memory or attention;

• stuttering, tremors, uncontrolled muscle movements;

• suicidal thoughts or actions;

• hallucinations, sleep problems, vivid dreams, sleep-walking; or

• compulsive or repetitive behaviors.

Also call your doctor at once if you have:

• worsening or no improvement in your asthma symptoms; or

• liver problems--nausea, loss of appetite, stomach pain (upper right side), tiredness, itching, dark urine, jaundice (yellowing of the skin or eyes).

Common side effects of zafirlukast may include:

• nausea, diarrhea, stomach pain;

• headache; or

• cold symptoms such as stuffy nose, sneezing, sore throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

Warnings

Tell your doctor right away if you have signs of blood vessel inflammation: flu-like symptoms, severe sinus pain, a skin rash, numbness or a "pins and needles" feeling in your arms or legs.

Stop taking this medicine and call your doctor right away if you have any unusual changes in mood or behavior (such as agitation, confusion, depression, sleep problems, compulsive behaviors, hallucinations, or suicidal thoughts or actions).

Before taking this medicine

You should not use zafirlukast if you are allergic to it, or if you have liver disease (including cirrhosis).

Tell your doctor if you have ever had liver disease.

Not approved for use by anyone younger than 5 years old.

The chewable tablet may contain phenylalanine and could be harmful if you have phenylketonuria (PKU).

It is not known if zafirlukast will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

You should not breastfeed while using zafirlukast.

How should I take zafirlukast?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Zafirlukast is not a fast-acting rescue medicine for asthma attacks. Seek medical attention if your breathing problems get worse quickly, or if you think your medications are not working.

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

Your dose needs may change due to surgery, illness, stress, or a recent asthma attack. Do not change your dose or stop using asthma medication without your doctor's advice.

Keep using zafirlukast as directed, even if you have no asthma symptoms.

If you take oral steroid medicine, do not stop it suddenly. Ask your doctor about tapering your dose.

Store at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use.

Zafirlukast dosing information

Usual Adult Dose for Asthma -- Maintenance:

-20 mg orally twice a day, 1 hour before or 2 hours after meals

Comments:
-A dose of 20 mg twice daily was not associated with an increase in the overall incidence of adverse events or withdrawals in elderly patients.

Use: Prophylaxis and chronic treatment of asthma

Usual Pediatric Dose for Asthma -- Maintenance:

Less than 5 years: The safety and effectiveness has not been established.

5 to 11 years:
-10 mg orally twice a day, 1 hour before or 2 hours after meals

12 years or older:
-20 mg orally twice a day, 1 hour before or 2 hours after meals

Use: Prophylaxis and chronic treatment of asthma

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking zafirlukast?

Avoid situations or activities that may trigger an asthma attack.

What other drugs will affect zafirlukast?

Tell your doctor about all your other medicines, especially:

• erythromycin;

• fluconazole;

• theophylline; or

• warfarin, Coumadin, Jantoven.

This list is not complete. Other drugs may affect zafirlukast, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

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.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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