Rubraca (rucaparib) is a brand-name drug that’s prescribed for certain types of cancer in adults. Rubraca comes as an oral tablet that’s typically taken twice per day. The dosage can vary depending on several factors.

Rubraca is prescribed to treat the following types of cancer in adults:

Rubraca is typically prescribed after you’ve already tried other treatments for your cancer.

Rubraca belongs to a drug class called poly (ADP-ribose) polymerase (PARP) inhibitors. Rubraca is not available in a generic version.

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

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

The information below describes Rubraca’s typical dosage and other details about the drug.

Rubraca form

Rubraca comes as an oral tablet.

Rubraca strengths

Rubraca comes in three strengths:

  • 200 milligrams (mg)
  • 250 mg
  • 300 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 ovarian cancer, fallopian tube cancer, and peritoneal cancer

Doctors may prescribe Rubraca to treat cancer of the ovaries, fallopian tubes, or peritoneum. In some cases, cancer of the fallopian tubes or peritoneum may resemble ovarian cancer. Due to this, your doctor may also refer to them as ovarian cancer.

If your doctor prescribes Rubraca for these cancers, your dose will likely be 600 mg (two 300-mg tablets). You’ll take this dose twice per day.

If you experience bothersome side effects while taking Rubraca, your doctor may lower your dosage. For details, see the “Dosage adjustments” section below. Always take the dosage your doctor recommends.

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

Dosage for prostate cancer

Rubraca is also approved to help treat castration-resistant prostate cancer. In this case, Rubraca is typically prescribed in combination with a gonadotropin-releasing hormone (GnRH) drug or after surgical castration. The recommended dosage is 600 mg (two 300-mg tablets) taken twice per day.

If you experience bothersome side effects while taking Rubraca, your doctor may lower your dosage. See the “Dosage adjustments” section just below for more information. Always take the dosage your doctor recommends.

Long-term treatment

Rubraca is meant to be taken as a long-term treatment for as long as your body responds well to the drug. If you and your doctor determine that Rubraca is safe and effective for you, you’ll likely take it long term.

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

The Rubraca dosage your doctor prescribes will depend on the side effects you may experience during treatment.

Dosage adjustments

If you experience bothersome side effects while taking Rubraca, your doctor may pause your treatment. Or they may lower your dose by 100 mg at a time. If necessary, they may do this up to three times, to a minimum dosage of 300 mg twice per day.

Be sure to tell your doctor about any side effects you experience during treatment with Rubraca.

Rubraca comes as an oral tablet that you swallow whole. The drug’s prescribing information doesn’t say whether to crush, chew, or split the tablets. You may take your dose with or without food.

Your doctor will likely recommend that you take your Rubraca doses 12 hours apart. This helps maintain a steady level of the drug in your body so Rubraca 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 use Rubraca, 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 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 your medication in an easy-open container. They also may recommend tools that can make it easier to open bottles.

If you miss a dose of Rubraca, take your next dose at the usual scheduled time. Do not take an extra dose to make up for the missed one. If you’re not sure whether you should take a missed dose or skip it, talk with your doctor or pharmacist.

If you vomit after taking a dose of Rubraca, do not take an extra dose. Take your next dose at the usual scheduled time.

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 Rubraca 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 Rubraca

Call your doctor right away if you believe you’ve taken too much Rubraca. 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 Rubraca.

Is the dosage of Rubraca similar to the dosage of Lynparza?

Yes, the forms and how often you take each drug are similar. Rubraca and Lynparza (olaparib) are both oral tablets that are taken twice per day.

However, the drugs contain different active ingredients. For this reason, they come in different strengths and doses. 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. You can also refer to this article about Lynparza and dosage.

How long does it take for Rubraca to start working?

Rubraca 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 Rubraca treatment.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Rubraca 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 Rubraca without your doctor’s recommendation. If you have questions about the dosage of Rubraca that’s best for you, talk with your doctor.

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

  • More about Rubraca: For information about other aspects of Rubraca, refer to this article.
  • Details about your condition: For details about the types of cancer that Rubraca is prescribed to treat, see our hubs on ovarian cancer and prostate cancer.

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.