Rituximab: uses, dosing, side effects & brands

How rituximab is dosed

From the FDA label for Rituxan (application BLA103705). Other rituximab products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.

Administer only as an intravenous infusion ( 2.1 ). Do not administer as an intravenous push or bolus ( 2.1 ). RITUXAN should only be administered by a healthcare professional with appropriate medical support to manage severe infusion-related reactions that can be fatal if they occur. ( 2.1 ). The dose for adult and pediatric B-cell NHL is 375 mg/m 2 ( 2.2 ). The dose for CLL is 375 mg/m 2 in the first cycle and 500 mg/m 2 in cycles 2–6, in combination with FC, administered every 28 days ( 2.3 ). The dose as a component of Zevalin ® (ibritumomab tiuxetan) Therapeutic Regimen is 250 mg/m 2 ( 2.4 ). The dose for RA in combination with methotrexate is two-1,000 mg intravenous infusions separated by 2 weeks (one course) every 24 weeks or based on clinical evaluation, but not sooner than every 16 weeks. Methylprednisolone 100 mg intravenous or equivalent glucocorticoid is recommended 30 minutes prior to each infusion ( 2.5 ). The induction dose for adult patients with active GPA and MPA in combination with glucocorticoids is 375 mg/m 2 once weekly for 4 weeks. The follow up dose for adult patients with GPA and MPA who have achieved disease control with induction treatment, in combination with glucocorticoids is two 500 mg intravenous infusions separated by two weeks, followed by a 500 mg intravenous infusion every 6 months thereafter based on clinical evaluation ( 2.6 ). The…

Rituximab side effects

Who shouldn’t take rituximab

Rituximab drug interactions

Combination products containing rituximab

A combination is a different drug — different dosing, different warnings. It is listed here so you can find it, not so you can substitute it.

• Rituxan Hycela

How long rituximab keeps

The date on a sealed pack is not the only one: some rituximab labels start a second clock once the product is opened or mixed, as short as 24 hours.

Rituximab and breastfeeding

From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.

Rituximab is a genetically engineered chimeric murine/human monoclonal antibody that targets CD20, a B-cell-specific surface antigen. The amount in milk is very low. It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal. Numerous breastfed infants apparently experienced no adverse effects during maternal use of rituximab, including no adverse effect on the CD19 +B cell count. The manufacturer recommends that breastfeeding be discontinued during rituximab therapy and for 6 months after the last dose. However, professional guidelines consider rituximab to be acceptable for use during breastfeeding. Waiting for at least 2 weeks postpartum to resume therapy may minimize transfer to the infant. Breastfeeding can resume after the injection. One group recommends waiting for 4 hours after the pre-injection antihistamine dose before resuming breastfeeding.

National Institute of Child Health and Human Development, record revised July 15, 2026. LactMed states its information is not a substitute for professional judgement.

What people report to the FDA about rituximab

The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 173,359 reports naming rituximab, and the FDA flagged 95% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:

• rheumatoid arthritis16,338 reports
• fatigue13,769 reports
• pneumonia11,657 reports
• rash11,082 reports
• arthralgia10,950 reports
• drug intolerance10,439 reports
• infusion related reaction10,424 reports
• pyrexia10,235 reports

Source: openFDA drug/event (FAERS), retrieved July 26, 2026.

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