Home Drug Guide Rituximab-arrx

Drug Guide

Generic Name

Rituximab-arrx

Brand Names Riabni

Classification

Therapeutic: Antineoplastic; Immunosuppressant

Pharmacological: Monoclonal antibody (anti-CD20)

FDA Approved Indications

  • Non-Hodgkin lymphoma
  • Chronic lymphocytic leukemia
  • Rheumatoid arthritis (in combination with methotrexate)
  • Granulomatosis with polyangiitis
  • Microscopic polyangiitis

Mechanism of Action

Rituximab-arrx is a chimeric monoclonal antibody that targets CD20, a surface antigen found on B lymphocytes. It destroys B cells through multiple mechanisms including antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and induction of apoptosis, leading to depletion of circulating B cells.

Dosage and Administration

Adult: Dosage varies depending on indication; typically, 375 mg/m2 weekly for 4 weeks for lymphomas, with adjustments as per specific protocols.

Pediatric: Used in specific indications; dosing based on body surface area or weight, according to clinical guidelines.

Geriatric: No specific dose adjustments solely based on age, but renal and hepatic function should be considered.

Renal Impairment: No specific adjustments; monitor closely.

Hepatic Impairment: No specific adjustments; monitor closely.

Pharmacokinetics

Absorption: Administered intravenously; bioavailability is 100% via IV route.

Distribution: Distributed primarily in the blood and lymphoid tissues.

Metabolism: Metabolized via catabolic pathways like other IgG antibodies.

Excretion: Excreted via protein catabolism; not eliminated via urine or feces significantly.

Half Life: Approximately 19-22 days in adults; varies with dose and patient factors.

Contraindications

  • Hypersensitivity to rituximab or any component of the formulation

Precautions

  • Increased risk of infections due to immune suppression; hepatitis B reactivation; infusion reactions; progressive multifocal leukoencephalopathy (PML)

Adverse Reactions - Common

  • Infusion reactions (fever, chills, hypotension) (Common)
  • Infections (upper respiratory, urinary tract) (Common)
  • Nausea, fatigue, headache (Common)

Adverse Reactions - Serious

  • Severe infusion reactions including anaphylaxis (Rare)
  • Progressive multifocal leukoencephalopathy (PML) (Very rare)
  • Severe infections, including opportunistic infections (Rare)
  • Hematologic toxicities, such as thrombocytopenia or leukopenia (Uncommon)

Drug-Drug Interactions

  • Other immunosuppressants, live vaccines, anthracyclines

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor complete blood counts, signs of infection, infusion reactions, respiratory status, and hepatic function.

Diagnoses:

  • Risk for infection related to immunosuppression
  • Risk for infusion reaction
  • Impaired skin integrity at infusion site

Implementation: Administer premedication (antihistamines, corticosteroids, antipyretics) as indicated; monitor during and after infusion; ensure resuscitation equipment is available.

Evaluation: Monitor for adverse effects, effectiveness of therapy, and timely management of side effects.

Patient/Family Teaching

  • Report fever, chills, rash, or difficulty breathing immediately.
  • Use effective contraception during and for 12 months after treatment.
  • Avoid live vaccines during therapy and for at least 6 months afterward.
  • Stay hydrated and report signs of infections or infusion reactions.

Special Considerations

Black Box Warnings:

  • Fatal infusion reactions, PML, severe mucocutaneous reactions, hepatitis B reactivation, tumor lysis syndrome

Genetic Factors: Testing for hepatitis B virus before initiation recommended.

Lab Test Interference: May cause false elevations in serum immunoglobulin levels and impact serology tests.

Overdose Management

Signs/Symptoms: Hypersensitivity, severe infusion reactions, blood dyscrasias.

Treatment: Supportive care; discontinuation of infusion; monitor vital signs and provide symptomatic treatment as needed.

Storage and Handling

Storage: Store refrigerated at 2°C to 8°C (36°F to 46°F). Protect from light.

Stability: Use within the specified period as per manufacturer instructions; discard unused portion.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.