Nurses Compass
Drug Guide
Cetuximab
Classification
Therapeutic: Antineoplastic, Monoclonal Antibody
Pharmacological: EGFR inhibitor
FDA Approved Indications
- Locally or regionally advanced squamous cell carcinoma of the head and neck
- METASTATIC colorectal cancer that expresses the epidermal growth factor receptor (EGFR)
Mechanism of Action
Cetuximab is a chimeric monoclonal antibody that binds to the extracellular domain of the epidermal growth factor receptor (EGFR), inhibiting ligand binding and subsequent receptor activation. This inhibits cell proliferation and induces apoptosis in tumor cells overexpressing EGFR.
Dosage and Administration
Adult: Initial dose: 400 mg/m² IV over 120 minutes, followed by weekly infusions of 250 mg/m² over 60 minutes.
Pediatric: Not approved for pediatric use.
Geriatric: No specific dose adjustment required, but caution in elderly patients due to potential for increased toxicity.
Renal Impairment: No specific recommendations, but close monitoring advised.
Hepatic Impairment: No specific data; use caution.
Pharmacokinetics
Absorption: Administered intravenously; bioavailability not applicable.
Distribution: Widely distributed in body tissues.
Metabolism: Metabolized by proteolytic enzymes.
Excretion: Metabolized similar to endogenous immunoglobulins; renal excretion not significant.
Half Life: Approximately 5-8 days.
Contraindications
- Hypersensitivity to cetuximab or any component of the formulation.
Precautions
- Use with caution in patients with cardiac disease, pulmonary fibrosis, or active infections. Risk of infusion reactions and skin toxicity. Discontinue if severe infusion reactions occur.
Adverse Reactions - Common
- Infusion reactions (Approximately 3-5%)
- Acneiform rash (Common, up to 80%)
- Fatigue (Common)
- Mucocutaneous dryness, pruritus (Common)
Adverse Reactions - Serious
- Anaphylaxis (Rare)
- Cardiac arrest (rare) (Very rare)
- Severe skin reactions, interstitial lung disease (rare) (Rare)
Drug-Drug Interactions
- Chemotherapy agents such as cisplatin, fluorouracil, irinotecan may increase toxicity.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor for infusion reactions, skin toxicity, signs of cardiopulmonary issues.
Diagnoses:
- Risk for infusion reaction
- Impaired skin integrity
Implementation: Premedicate with antihistamines or corticosteroids as appropriate. Monitor skin and patient response.
Evaluation: Assess for adverse reactions, effectiveness of tumor response, and skin changes.
Patient/Family Teaching
- Report any infusion reactions such as difficulty breathing, swelling, or rash.
- Use sun protection to minimize skin reactions.
- Report new or worsening symptoms immediately.
Special Considerations
Black Box Warnings:
- Serious infusion reactions may occur, including fatal reactions.
- Cardiac arrest has occurred rarely.
Genetic Factors: KRAS mutation status may guide use in colorectal cancer; only use in KRAS wild-type tumors.
Lab Test Interference: EGFR expression testing required for some indications.
Overdose Management
Signs/Symptoms: Hypersensitivity reactions, cardiac arrhythmias, skin reactions.
Treatment: Discontinue infusion; provide supportive care; no specific antidote.
Storage and Handling
Storage: Store refrigerated at 2-8°C.
Stability: Stable until the expiration date on the vial.