HomeCyclophosphamideCyclophosphamide + Rituximab Arrx

Does Cyclophosphamide Interact with Rituximab Arrx?

Cyclophosphamide and Rituximab Arrx have a unknown drug interaction according to U.S. FDA drug labeling data. In patients with CLL, rituximab did not alter systemic exposure to fludarabine or cyclophosphamide. In clinical trials of patients with RA, concomitant administration of methotrexate or cyclophosphamide did not alter the pharmacokinetics of rituximab. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.

Severity
Unknown
Cyclophosphamide Class
Alkylating Drug
Rituximab Arrx Class
CD20-directed Cytolytic Antibody
Management
Consult your pharmacist
Data Source
U.S. FDA via OpenFDA

What To Tell Your Doctor or Pharmacist

If you are taking Cyclophosphamide and your doctor is considering prescribing Rituximab Arrx (or vice versa), make sure to:

  • Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
  • Ask whether the benefits of combining these medications outweigh the risks for your specific situation
  • Ask what symptoms to watch for that would indicate the interaction is causing problems
  • Never stop or change either medication without first consulting your healthcare provider
💊 Cyclophosphamide(Frindovyx)+💊 Rituximab Arrx(Riabni)

Severity & Interaction Details

ℹ️
unknown
Interaction documented — severity unclassified
The FDA label notes an interaction but the severity is not classified in our dataset.
Severity scale
MinorContra
On record
Yes
Drug A class
Alkylating Drug
Drug B class
CD20-directed Cytolytic Antibody
Source
FDA drug label - rituximab-arrx

What this means in plain English

In patients with CLL, rituximab did not alter systemic exposure to fludarabine or cyclophosphamide. In clinical trials of patients with RA, concomitant administration of methotrexate or cyclophosphamide did not alter the pharmacokinetics of rituximab.

About Cyclophosphamide and Rituximab Arrx

Cyclophosphamide is an Alkylating Drug, while Rituximab Arrx is a CD20-directed Cytolytic Antibody. You may recognize them by the brand names Frindovyx and Riabni. Both medications are given by intravenous (IV) infusion. Rituximab Arrx additionally carries an FDA boxed warning, the FDA's strongest safety alert.

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Data integrity: Every interaction shown is extracted directly from official U.S. FDA drug labeling via openFDA and the U.S. National Library of Medicine (NIH) — no interactions are invented, inferred, or manually edited. Maintained by CheckDrugInteractions.com. See our methodology or report a correction at support@checkdruginteractions.com.

Data sourced from U.S. FDA drug labeling via openFDA and the NIH National Library of Medicine, supplemented with a small number of well-established interactions from curated clinical references. For informational purposes only. Always consult your pharmacist or physician.