If you have a certain type of arthritis, cancer, or rare autoimmune condition, your doctor might suggest Rituxan (rituximab) as a treatment option. As a result, you could be looking for more information about the drug, such as details about dosage.

Rituxan is a prescription medication used to treat the following conditions in adults:

It’s also used to treat the following conditions in adults and some children:

Rituxan is part of a group of drugs called monoclonal antibodies. These drugs are proteins that work with the immune system. Rituxan is also considered an antineoplastic drug (a drug that treats cancer).

This article describes the dosages of Rituxan, including its form, strengths, and how the drug is given. To learn more about Rituxan, see this in-depth article.

There is another form of rituximab called Rituxan Hycela. It’s given as an injection under the skin. Learn more about Rituxan Hycela dosing in this article.

Note: Below, you’ll find information on Rituxan’s typical dosages, which are provided by the drug’s manufacturer. But when using Rituxan, you’ll always receive the dosage that your doctor prescribes.

Rituxan is an intravenous (IV) infusion. This is an injection into your vein given over a period of time. The specific dose of the drug that you get will depend on several factors:

  • height
  • weight
  • age
  • the condition being treated

A healthcare professional will give you the infusion at a doctor’s office or infusion center.

What is Rituxan’s form?

Rituxan is available as a liquid solution in single-dose vials for injection.

What strengths does Rituxan come in?

Rituxan comes in the following strengths:

  • 100 milligrams (mg)/10 milliliters (mL)
  • 500 mg/50 mL

What are the typical dosages of Rituxan?

The information below describes Rituxan dosages that are commonly used or recommended. Your doctor will determine the best dosage to fit your needs.

Induction and follow-up doses

A Rituxan treatment sometimes includes several doses given over a period of a few weeks.

For certain conditions, your doctor will start with a slower infusion for induction. Induction, or induction dosage, refers to your first treatment. It may be just one dose or many doses over a period of a few weeks. Induction is used to help reduce the symptoms of your condition quickly.

Then you may be given follow-up doses to make sure your condition stays controlled and doesn’t get worse. Follow-up doses are also sometimes called maintenance therapy.

Your doctor may adjust your Rituxan dose over time based on your body’s reaction.

Dosing for rheumatoid arthritis (RA)

When you first start Rituxan treatment for RA, you’ll receive two 1,000-milligram (mg) infusions. These are given 2 weeks apart.

Your next infusions may be given 16 to 24 weeks later. The timing will depend on how you respond to the first doses. You’ll again receive two 1,000-mg infusions, with 2 weeks between each infusion. This dosage will be repeated every 16 to 24 weeks.

To help prevent infusion reactions, your doctor may give you a corticosteroid, such as Solu-Medrol (methylprednisolone), before the Rituxan infusion.

You’ll also take another drug, Trexall (methotrexate), while you’re receiving Rituxan. These two drugs work together to treat your condition.

Dosing for granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA)

The following dosage information is for adults who have GPA (also known as Wegener’s granulomatosis) or MPA. For dosage information specific to children with these conditions, see the “What’s the dosage of Rituxan for children?” section below.

Induction dosage

The typical first dose of Rituxan for GPA and MPA is 375 mg/meters squared (m2). Meters squared is a measure of body surface area. Your doctor will calculate your body surface area based on your height and weight. They’ll use this to figure out how much Rituxan you should get.

The first dose is an induction dose, and you’ll receive this every week for 4 weeks.

To help prevent infusion reactions, your doctor may give you methylprednisolone. They may then switch you to prednisone.

Follow-up dosage

Your follow-up doses of Rituxan may start from 16 to 24 weeks after your induction doses. The timing depends on your body’s response to the drug.

If your condition was first treated with a drug other than Rituxan, the follow-up time is different. In this case, the follow-up doses of Rituxan will start within 4 weeks after symptoms of your condition are controlled.

The typical first follow-up Rituxan dose is 500 mg, which is given twice. There will be 2 weeks between each dose.

After that, you may be given a 500-mg dose once every 6 months. Ask your doctor how long you may receive Rituxan.

Dosing for non-Hodgkin’s lymphoma (NHL)

The typical dose of Rituxan for NHL is 375 mg/m2. Your doctor will calculate the exact amount based on your height and weight. The timing of the doses for different categories of NHL* are as follows:

  • NHL that has returned or didn’t respond to treatment: You’ll receive an infusion once each week for 4 or 8 weeks.
  • Previously treated NHL that has returned or didn’t respond to treatment: You’ll receive an infusion once each week for 4 weeks.
  • Previously untreated NHL: For this use, you’ll also have chemotherapy with Rituxan treatment. You’ll receive a Rituxan infusion on the first day of each chemotherapy cycle for up to eight cycles.† If you have a good response to Rituxan, you may keep getting Rituxan infusions after your chemotherapy is finished. These are called maintenance doses, and they start 8 weeks after your chemotherapy. You’ll get these maintenance Rituxan infusions once every 8 weeks. This schedule will last for 12 doses.
  • NHL that isn’t worsening after you finish first-line CVP (cyclophosphamide, vincristine, prednisone) chemotherapy: You’ll typically start Rituxan treatment after you finish six to eight chemotherapy cycles. You’ll receive a Rituxan infusion once each week for 4 weeks. After 6 months, you may again receive an infusion of Rituxan once each week for 4 weeks. This dosing schedule can be repeated up to four times for a total of 16 doses.
  • Diffuse large B-cell lymphoma (DLBCL): For DLBCL, you’ll receive a Rituxan infusion on day 1 of your chemotherapy cycle. This can be repeated for up to 8 cycles.

If you have questions about the frequency of your Rituxan infusions, ask your doctor.

* For specifics about the categories of NHL that Rituxan is used to treat, see this in-depth article.
† “Chemotherapy cycle” refers to your chemotherapy treatment and the weeks afterward when your body rests.

Dosing for chronic lymphocytic leukemia (CLL)

For treating CLL, you’ll take Rituxan with chemotherapy using fludarabine and cyclophosphamide.

The typical first dose of Rituxan for CLL is 375 mg/m2. Your doctor will calculate the exact amount based on your height and weight. This dose is given the day before the first cycle of chemotherapy.

This is usually followed by a Rituxan infusion of 500 mg/m2. This dose is given on the first day of cycles 2 to 6 of your chemotherapy. So Rituxan dosing will likely be every 28 days.

Dosing for pemphigus vulgaris (PV)

When you first start Rituxan treatment for moderate to severe PV, you’ll receive two Rituxan infusions of 1,000 mg. These are given 2 weeks apart. You’ll also take a corticosteroid medication, which will be decreased slowly over time.

The typical maintenance dose of Rituxan is 500 mg, given 12 months later. Depending on your response, you may receive this dose every 6 months.

You may also be treated with Rituxan if you have a PV relapse. That means the disease gets worse again after it was controlled. For a relapse, the typical dose of Rituxan is 1,000 mg. Your doctor may restart or increase the dose of corticosteroids based on your symptoms.

The earliest that you can receive a dose of Rituxan is 16 weeks after the last dose.

Dosing when used with Zevalin

In addition to its other uses, Rituxan is part of a treatment regimen called Zevalin, which also includes a drug called ibritumomab tiuxetan. Zevalin is used to treat certain types of NHL. The typical dose of Rituxan, in this case, is 250 mg/m2. Your doctor will calculate the exact amount based on your height and weight.

You can learn more about Zevalin at the manufacturer’s website.

What’s the dosage of Rituxan for children?

Rituxan can be used to treat GPA or MPA in children ages 2 years and older.

Induction dosage

The typical first dose of Rituxan for children with GPA and MPA is 375 mg/m2. A doctor will calculate the exact amount based on your child’s height and weight. Your child will receive this dose once each week for 4 weeks.

Before the first infusion, your child will receive methylprednisolone. This is to help prevent infusion reactions. After a few days, the doctor may then switch your child to a steroid drug taken by mouth.

Follow-up dosage

Your child will likely receive follow-up doses of Rituxan within 16 to 24 weeks. If they received induction treatment with a different drug, they’ll start follow-up treatment with Rituxan within 4 weeks after symptoms of their condition are controlled.

The first follow-up Rituxan dose is typically 250 mg/m2 given twice. There will be 2 weeks between each dose. Depending on your child’s response, this may be followed by a single infusion of the same dose once every 6 months.

Is Rituxan used long term?

You may receive up to 16 Rituxan doses depending on the condition you’re using the drug to treat. Ask your doctor about how long you’ll be taking Rituxan.

Dosage adjustments

Your Rituxan dosage may be calculated based on your height and weight.

Your doctor may adjust your dosage based on the following factors:

  • changes to other medications you may take
  • changes in your weight
  • an active infection

Your doctor may also adjust your dosage depending on how you respond to treatment.

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

  • the type and severity of the condition you’re using Rituxan to treat
  • age, height, and weight
  • the strength of Rituxan you’re using
  • your reaction to the first Rituxan dose
  • other conditions you may have or certain factors (see “Dosage adjustments” under “What is Rituxan’s dosage?”)

A healthcare professional will give you Rituxan as an intravenous (IV) infusion. This is an injection into your vein given over a period of time. Your first Rituxan infusion will likely be given slowly and may take about 4 to 6 hours. The next Rituxan infusions may be faster, taking about 3 to 4 hours.

You may receive certain drugs before your Rituxan infusion. These are called premedications, and they’re used to make the Rituxan dose safer for your body. An example is a corticosteroid called methylprednisolone. (A corticosteroid is a type of drug that decreases harmful immune system reactions.)

You’ll receive your Rituxan infusions at a doctor’s office or an infusion center. Your doctor will explain the process in detail to you. You can also visit the manufacturer’s website for more information. The website has descriptions for each condition that Rituxan treats.

If you still have questions or concerns about how Rituxan is given, talk with your doctor.

If you can’t make it to an infusion appointment, let your doctor know right away. You may need to reschedule. Your dosing schedule may also need to be adjusted.

To help make sure you don’t miss an appointment, try writing down a reminder on a calendar or setting one on your phone.

The sections above describe the typical dosages provided by the drug manufacturer. If your doctor recommends Rituxan for you, they’ll prescribe the dosage that’s right for you.

If you have questions or concerns about your current dosage of Rituxan, talk with your doctor.

Here are some examples of questions you may want to ask your doctor:

  • Will my Rituxan dosage change if the medication isn’t working well enough for my condition?
  • Should my dosage be lowered if I’m noticing side effects from Rituxan?
  • How should I prepare for my Rituxan infusion?
  • Does my dosage of Rituxan change if I develop new health problems?
  • Will my blood test results change my Rituxan dosage?

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Disclaimer: Healthline 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.