Zydelig (idelalisib) is a brand-name drug that’s prescribed for relapsed chronic lymphocytic leukemia in adults. Zydelig comes as an oral tablet that’s typically taken twice per day. The dosage can vary depending on several factors.

Zydelig is approved by the Food and Drug Administration (FDA) to treat relapsed chronic lymphocytic leukemia (CLL). It’s prescribed along with rituximab (Rituxan) for adults who would be able to take Rituxan on its own.

Zydelig belongs to a drug class called kinase inhibitors. Zydelig is not available in a generic version.

Keep reading for specific information about the dosage of Zydelig, including its strengths and how to take the medication. For a comprehensive look at Zydelig, see this article.

Note: This article describes typical dosages for Zydelig provided by the drug’s manufacturer. When taking Zydelig, always follow the dosage prescribed by your doctor.

The information below describes Zydelig’s typical dosages and other details about the drug.

Zydelig form

Zydelig comes as an oral tablet.

Zydelig strengths

Zydelig comes in two strengths: 100 milligrams (mg) and 150 mg.

Typical dosages

The following information describes dosages that are commonly prescribed or recommended in adults. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Dosage for CLL

Doctors may prescribe Zydelig to treat relapsed CLL. For this use, the drug is typically prescribed in combination with rituximab (Rituxan).

If your doctor prescribes Zydelig for your CLL, your dose will likely be 150 mg. You’ll take this twice per day.

For more information about your specific dosage, talk with your doctor.

Long-term treatment

Zydelig is meant to be taken as a long-term treatment. If you and your doctor determine that Zydelig is safe and effective for you, you’ll likely take it as long as it’s working for your condition and as long as you don’t have any serious side effects.

Before you start taking Zydelig, your doctor will discuss your treatment plan with you.

The Zydelig dosage your doctor prescribes will depend on several factors. These include:

  • how your body responds to Zydelig
  • other medications you take
  • side effects you may have with Zydelig
  • your liver function

Other medical conditions you have can also affect your Zydelig dosage.

Dosage adjustments

Your doctor may need to adjust your dosage if you experience certain side effects while taking Zydelig. In some cases, they’ll recommend pausing your treatment or stopping the drug altogether.

Be sure to tell your doctor about all medications you take and any health conditions you may have.

For more details about the side effects Zydelig can cause, talk with your doctor. You can also refer to this article.

Zydelig comes as an oral tablet that you swallow whole. Do not divide, crush, chew, or place the tablet in water. You may take your dose with or without food.

It may be helpful to take Zydelig around the same time of day. This helps maintain a steady level of the drug in your body so Zydelig can work effectively.

If you have trouble swallowing tablets, see this article for tips on how to take this form of medication. You can also talk with your doctor or pharmacist.

If you have questions about how to take Zydelig, talk with your doctor or pharmacist.


Some pharmacies offer labels with large print, braille, or a code you scan with a smartphone to convert text to speech. If your local pharmacy doesn’t have these options, your doctor or pharmacist might be able to recommend a pharmacy that does.

If you’re having trouble opening medication bottles, ask your pharmacist about putting Zydelig in an easy-open container. They also may recommend tools that can make it easier to open bottles.

If you miss a dose of Zydelig, take it as soon as you remember. If it’s been 6 or more hours since your missed dose, skip the missed dose and take your next scheduled dose. If you’re not sure whether you should take a missed dose or skip it, talk with your doctor or pharmacist.

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm or putting a note where you’ll see it, such as on your bathroom mirror or bedside table. You could also download a reminder app on your phone.

It’s important that you don’t take more Zydelig than your doctor prescribes. For some medications, taking more than the recommended amount may lead to harmful effects or overdose.

If you take more than the recommended amount of Zydelig

Call your doctor right away if you believe you’ve taken too much Zydelig. Another option is to call America’s Poison Centers at 800-222-1222 or use its online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.

Below are some frequently asked questions about Zydelig.

Is the dosage of Zydelig similar to the dosage of Venclexta?

No, the dosage of Zydelig isn’t similar to the dosage of venetoclax (Venclexta). While Zydelig and Venclexta are both oral tablets, they’re taken differently. Zydelig is taken twice per day, while Venclexta is taken once per day.

The dose in milligrams for each drug also differs because they have different active ingredients. Your doctor will prescribe the drug and the dosage that’s right for you.

To learn more about how these drugs compare, talk with your doctor.

How long does it take for Zydelig to start working?

Zydelig starts to work after your first dose. Because of how the drug works, you likely won’t feel the drug working in your body. But your doctor will monitor you during treatment to check whether the drug is working to treat your condition.

Talk with your doctor if you have questions about what to expect with Zydelig treatment.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Zydelig for you, they will prescribe the dosage that’s right for you. Always follow the dosage that your doctor prescribes.

As with any drug, never change your dosage of Zydelig without your doctor’s recommendation. If you have questions about the dosage of Zydelig that’s best for you, talk with your doctor.

Besides learning about dosage, you may want other information about Zydelig. These additional articles might be helpful:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.