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RITUXIMAB

Medical Diagnosis and Drugs, Medications
RITUXIMAB
(rit-ux'i-mab)
Rituxan
Classifications: antineoplastic agent; immunomodulator; disease-modifying antirheumatic drug (dmard);
Therapeutic:antineoplastic; monoclonal antibody; antirheumatic agent; dmard
Pregnancy Category: C

Availability

10 mg/mL injection

Action

Genetically engineered monoclonal antibody that binds with the CD20 antigen on the surface of normal and malignant B lymphocytes. B-cells are believed to play a role in the pathogenesis of rheumatoid arthritis and associated chronic synovitis. B-cells may be acting at multiple sites in the autoimmune/inflammatory process including rheumatoid factor and other autoantibody production, antigen presentation, T-cell activation, and/or proinflammatory cytokine production.

Therapeutic Effect

Results in a rapid and sustained depletion of circulating and tissue-based (e.g., thymus, spleen) B lymphocytes in non-Hodgkin's lymphoma. Used in combination with methotrexate to reduce signs and symptoms of moderately to severely active rhematoid arthritis (RA) in adults with an inadequate response to one or more TNF antagonist therapies. Rituximab effectiveness in treatment for rheumatoid arthritis is measured by induced depletion of peripheral B lymphocytes.

Uses

Relapsed or refractory CD20 positive, B-cell non-Hodgkin's lymphoma, treatment of rheumatoid arthritis (with methotrexate).

Contraindications

Hypersensitivity to murine proteins, rituximab, or abciximab; angina, cardiac arrhythmias, cardiac disease; pulmonary disease, chronic lymphocytic leukemia (CLL), lymphoma, severe hypotension; oliguria, rising serum creatinine; viral hepatitis B (HBV), vaccination; pregnancy (category C), lactation.

Cautious Use

Prior exposure to murine-based monoclonal antibodies; history of allergies; asthma and other pulmonary disease (increased risk of bronchospasm); respiratory insufficiency; older adults; CAD; thrombocytopenia; history of cardiac arrhythmias; hypertension, renal impairment. Safety and efficacy in children are not established.

Route & Dosage

Non-Hodgkin's Lymphoma
Adult: IV 375 mg/m2 infused at 50 mg/h, may increase infusion rate q30min (max: 400 mg/h if tolerated), repeat dose on days 8, 15, and 22 (total of 4 doses)

Rheumatoid Arthritis
Adult: IV 1000 mg on days 1 and 15 (with methotrexate)

Administration

Intravenous

PREPARE: IV Infusion: Dilute ordered dose to 1–4 mg/mL by adding to an infusion bag of NS or D5W. Examples: 500 mg in 400 mL yields 1 mg/mL; 500 mg in 75 mL yields 4 mg/mL. Gently invert bag to mix. Discard unused portion left in vial.  

ADMINISTER: IV Infusion: Infuse first dose at a rate of 50 mg/h; may increase rate at 50 mg/h increments q30min to maximum rate of 400 mg/h. For subsequent doses, infuse at a rate of 100 mg/h and increase by 100 mg/h increments q30min up to maximum rate of 400 mg/h.  

  • Slow or stop infusion if S&S of hypersensitivity appear (see Appendix F).
  • Store unopened vials at 2°–8° C (36°–46° F) and protect from light.

Adverse Effects (≥1%)

Body as a Whole: Angioedema, fatigue, asthenia, night sweats, fever, chills, myalgia. CNS: Headache, dizziness, depression. CV: Hypotension, tachycardia, peripheral edema. GI: Nausea, vomiting, throat irritation, anorexia, abdominal pain, hepatitis B reactivation with fulminant hepatitis, hepatic failure, and death. Hematologic: Leukopenia, thrombocytopenia, anemia, neutropenia. Respiratory: Bronchospasm, dyspnea, rhinitis. Skin: Pruritus, rash urticaria. Other: Infusion-related reactions: Fever, chills, rigors, pruritus, urticaria, pain, flushing, chest pain, hypotension, hypertension, dyspnea; fatal infusion-related reactions have been reported.

Interactions

Drug: antihypertensive agents should be stopped 12 h prior to avoid excessive hypotension; cisplatin may cause additive nephrotoxicity.

Pharmacokinetics

Duration: 6–12 mo. Half-Life: 60–174 h (increases with multiple infusions).

Nursing Implications

Assessment & Drug Effects

  • Lab tests: CBC with differential, peripheral CD20+ B lymphocytes.
  • Monitor carefully BP and ECG status during infusion and immediately report S&S of hypersensitivity (e.g., fever, chills, urticaria, pruritus, hypotension, bronchospasms; see Appendix F for others).

Patient & Family Education

  • Do not take antihypertensive medication within 12 h of rituximab infusions.
  • Note: Use effective contraception during and for up to 12 mo following rituximab therapy.
  • Report any of the following experienced during infusion: itching, difficulty breathing, tightness in throat, dizziness, headache, nausea.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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