Rituxan (rituximab) is a prescription brand-name medication. The Food and Drug Administration (FDA) has approved it to treat the following conditions in certain adults:

The FDA has also approved Rituxan to treat GPA and MPA in children ages 2 years and older.

Rituxan contains the active drug rituximab and belongs to a class of drugs called monoclonal antibodies. Rituxan is a biologic medication.

There are two biosimilar versions of Rituxan: Ruxience (rituximab-pvvr) and Truxima (rituximab-abbs).

Rituxan comes as a solution that’s given by a healthcare professional as an IV infusion.

For information about the dosage of Rituxan, including its form, strengths, and how it’s given, keep reading. For a comprehensive look at Rituxan, see this article.

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

Below is important information about Rituxan’s dosages for its approved uses.

Rituxan form

Rituxan comes as a solution that’s given as an IV infusion. Rituxan infusions are given by a healthcare professional and may be done at your doctor’s office, a hospital or clinic, or an infusion center.

Rituxan strengths

Rituxan is available in the following strengths:

  • 100 milligrams (mg) per 10 milliliters (ml) solution
  • 500 mg per 50 ml solution

Typical dosages

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

Your doctor may give you certain medications before each Rituxan dose. This is to prevent an infusion reaction (a side effect that can occur during or after an infusion). Rituxan has a boxed warning for severe infusion reaction.*

These drugs may include Tylenol (acetaminophen) and an antihistamine, such as Benadryl (diphenhydramine). For certain conditions, you may also be given a glucocorticoid drug, such as methylprednisolone.

If you have questions about the medications you may be given with Rituxan, talk with your doctor or pharmacist.

* A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). For more information, see “Boxed warnings” at the top of this article.

Dosage for rheumatoid arthritis

If you’re prescribed Rituxan for rheumatoid arthritis (RA), you’ll typically have a 1,000-milligram (mg) infusion for your first dose. This is followed by another 1,000-mg infusion 2 weeks later. If your doctor recommends additional doses, they’ll be given every 16 to 24 weeks as needed.

For RA, Rituxan is prescribed with methotrexate. Your doctor may also prescribe a glucocorticoid drug for you to take before each Rituxan dose. This is to decrease your risk of infusion reactions.

Dosages for granulomatosis with polyangiitis and microscopic polyangiitis

If your doctor prescribes Rituxan for granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), you will receive 375 mg per meters squared* (mg/m2) once weekly as an induction (starting) treatment. This will be given once weekly for 4 weeks.

If your condition improves with the induction treatment, you’ll likely receive follow-up doses 16 to 24 weeks after your last induction dose. With follow-up doses, you’ll receive two 500-mg doses of Rituxan 2 weeks apart. After that, you’ll continue with 500 mg of Rituxan every 6 months as needed.

To reduce the risk of infusion reaction, you may also receive glucocorticoids through an IV infusion. This will be given for 3 days before starting Rituxan treatment. You will also be given an oral glucocorticoid to reduce this risk. Your doctor will prescribe the glucocorticoids at the right time for you during your Rituxan treatment.

* Meters squared is a measurement that’s based on your height and weight. For example, if you weigh 70 kilograms (one kilogram is about 2.2 pounds) and you’re 1.7 meters tall (one meter is about 39.4 inches), your dose would likely be 682.5 mg/m2.

Dosages for non-Hodgkin lymphoma

If you are prescribed Rituxan for non-Hodgkin lymphoma (NHL),* you will receive 375 mg/m2 of Rituxan. How often you receive Rituxan will depend on the type of NHL you have:

  • NHL that has returned or didn’t respond to treatment. Rituxan is given once weekly for 4 to 8 weeks. After, Rituxan may be given once weekly for 4 more weeks as needed.
  • Previously untreated NHL. For this type of NHL, Rituxan is given with chemotherapy. A dose of Rituxan is given on day 1 of each cycle† of chemotherapy. This is done for up to 8 cycles. If your NHL improves, you’ll have 12 more doses of Rituxan. Each dose will be given 8 weeks apart.
  • NHL that isn’t worsening after chemotherapy. After 6 to 8 cycles of chemotherapy, Rituxan is given once weekly for 4 weeks. This dosage may be repeated every 6 months. The maximum dose of Rituxan for this type of NHL is 16 doses.
  • Diffuse large B-cell lymphoma. For diffuse large B-cell lymphoma, Rituxan is given with chemotherapy. A dose of Rituxan is given on day 1 of each chemotherapy cycle. This is done for up to 8 cycles.

* For more details about the different types of NHL that Rituxan is used to treat, see this article.
† A “cycle” of chemotherapy refers to a period of chemotherapy treatment followed by a period without treatment. This allows the body to rest before starting the next round of chemotherapy.

Dosage for chronic lymphocytic leukemia

To treat chronic lymphocytic leukemia, 375 mg/m2 of Rituxan is given the day before starting chemotherapy. After the first dose, you will receive 500 mg/m2 of Rituxan on day 1 of cycles two through six. This means you’ll have a Rituxan infusion once every 28 days.

Dosage for pemphigus vulgaris

To treat pemphigus vulgaris (PV), you’ll typically have a 1,000-mg infusion of Rituxan on the first visit. Then, you’ll receive another 1,000 mg of Rituxan 2 weeks later.

If your doctor recommends continuing Rituxan treatment for PV, you’ll receive 500 mg of Rituxan 12 months after your first two doses. You’ll then be given 500 mg every 6 months as needed.

If your PV relapses (comes back or gets worse after or during treatment), you can receive another dose of Rituxan sooner. For this purpose, you’ll receive 1,000 mg of Rituxan as early as 4 months after your most recent dose. After this, you’ll return to your normal dosing schedule of 500 mg every 6 months as needed.

These doses will be administered with a glucocorticoid drug to decrease your risk of having an infusion reaction. Your doctor will decrease your dosage of the glucocorticoid over time.

Children’s dosage

Rituxan is approved to treat GPA and MPA in children ages 2 years and older.

For this use, the child will receive an induction treatment of 375 mg/m2* once weekly for 4 weeks.

If the child’s condition has improved with the induction treatment, they may receive follow-up doses 16 to 24 weeks after their last induction dose. With follow-up doses, they’ll receive two 250-mg/m2 doses of Rituxan. These doses will be 2 weeks apart. After, the child may continue to receive 250 mg/m2 of Rituxan once every 6 months as needed.

A child may also receive an infusion of glucocorticoids for 3 days before starting Rituxan treatment. They may also be given an oral glucocorticoid to reduce the risk of an infusion reaction.†Their doctor will prescribe the glucocorticoids at the right time for them during their Rituxan treatment.

* Meters squared is a measurement that’s based on your height and weight. For example, if you weigh 32 kilograms (one kilogram is about 2.2 pounds) and you’re 1.4 meters tall (one meter is about 39.4 inches), your dose would likely be 408.75 mg/m2.
† Infusion reaction is a boxed warning of Rituxan. A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous. (For more information, see “Boxed warnings” at the top of this article.)

Long-term treatment

Rituxan may be used long-term for some conditions, such as RA. The amount of time and how often you receive Rituxan will depend on what condition you have and how well the treatment is working.

If you have questions about how long you will receive Rituxan, talk with your doctor.

Below are some frequently asked questions about Rituxan and their answers.

How does dosing compare for Rituxan vs. Rituxan Hycela?

Rituxan Hycela is a form of Rituxan that’s available as a subcutaneous injection. It contains the active drug rituximab/hyaluronidase human. Rituxan is given as an IV infusion and contains the active drug rituximab.

Rituxan Hycela is always prescribed in the same dose of 1,400 milligrams of rituximab and 23,400 units of hyaluronidase human per 11.7 milliliters of solution. However, how often and how long you take Rituxan Hycela can vary depending on your condition.

In comparison, Rituxan dosing is different for each of the conditions it’s used to treat. And the dose might be different based on your height and weight. So Rituxan dosing can be different for each person taking the drug. For more information, see “Rituxan dosage” just above.

For certain conditions, Rituxan Hycela might be injected after a Rituxan infusion. This depends on your treatment plan. If you have questions about this, talk with your doctor.

Why might the length of my Rituxan infusion change?

Rituxan infusions are injections into your vein that are given over time. Your first Rituxan infusion will be given slowly and will take longer than your next infusions. This is so your doctor can monitor you for symptoms of an infusion reaction.* (An infusion reaction is a side effect that can occur during or after an infusion.)

If you don’t experience a reaction to your first infusion, the rate of your infusion may be increased at your next visit. The faster the drug is infused, the shorter the length of the infusion.

If you develop infusion reaction symptoms during any Rituxan infusion, your doctor may slow down the rate of infusion. How long your infusion takes may depend on your condition and any other health conditions or symptoms you have. Talk with your doctor if you have any questions about the amount of time your infusion takes.

* Infusion reaction is a boxed warning of Rituxan. A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous. (For more information, see “Boxed warnings” at the top of this article.)

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

  • the type and severity of the condition you’re taking Rituxan to treat
  • your age
  • your height and weight

Other medical conditions you have can also affect your Rituxan dosage. If you have questions about factors that can affect your Rituxan dosage, talk with your doctor or pharmacist.

Rituxan comes as a solution that’s given as an IV infusion. Rituxan will be administered by a healthcare professional in your doctor’s office, a hospital or clinic, or an infusion center.

Before each infusion, you might be given medications to help prevent an infusion reaction (a side effect that can happen during or after an infusion). Rituxan has a boxed warning* for infusion reactions. See “Rituxan dosage” above for details about the medications you might be given to help prevent this side effect.

The Rituxan infusion can take several hours. The amount of time the infusion takes may depend on your condition, your Rituxan dosage, and any other health conditions or symptoms you may have. Talk with your doctor if you have any questions about the amount of time your infusions take.

* A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). For more information, see “Boxed warnings” at the top of this article.

If you miss an appointment, call your doctor to reschedule as soon as possible. Your doctor may adjust your dosing schedule or the timing of future doses.

Set a reminder in your phone or on a calendar to help you remember your appointments. You may be able to ask the hospital or doctor’s office to send you a reminder before your next appointment.

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

If you have questions about the dosage of Rituxan that’s right for you, talk with your doctor.

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

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.