Nurses Compass
Drug Guide
Panitumumab
Classification
Therapeutic: Antineoplastic Agent
Pharmacological: Monoclonal Antibody (EGFR inhibitor)
FDA Approved Indications
- Metastatic colorectal cancer (KRAS wild-type)
Mechanism of Action
Panitumumab binds to the epidermal growth factor receptor (EGFR), preventing the activation of the receptor and subsequent downstream signaling that promotes tumor cell proliferation.
Dosage and Administration
Adult: Initial dose of 6 mg/kg given intravenously every 2 weeks.
Pediatric: Not approved or recommended for pediatric use.
Geriatric: Adjust based on tolerability; no specific dose adjustment required solely based on age.
Renal Impairment: No specific adjustment; caution in severe impairment.
Hepatic Impairment: No specific adjustment; caution advised.
Pharmacokinetics
Absorption: Not applicable (intravenous infusion).
Distribution: Widely distributed; volume of distribution approximately 5-8 liters.
Metabolism: Metabolized through catabolism, not via liver enzymes.
Excretion: Excreted via protein catabolism, not renal or hepatic pathways.
Half Life: Approximately 4.5 days.
Contraindications
- Known hypersensitivity to panitumumab or any component of the formulation.
Precautions
- Risk of dermatologic toxicity, infusion reactions, electrolyte abnormalities, interstitial lung disease.
- Use caution in patients with pre-existing pulmonary fibrosis or interstitial lung disease.
Adverse Reactions - Common
- Skin rash (Common)
- Fatigue (Common)
- Pruritus (Common)
- Diarrhea (Common)
Adverse Reactions - Serious
- Infusion reactions (Less common)
- Interstitial lung disease (Rare)
- Electrolyte imbalances (hypomagnesemia, hypocalcemia) (Less common)
- Dermatologic toxicity leading to severe skin reactions (Less common)
Drug-Drug Interactions
- Concomitantuse with other EGFR inhibitors or chemotherapeutics
Drug-Food Interactions
- No significant food interactions reported.
Drug-Herb Interactions
- Limited data; caution with herbal supplements with potential for skin toxicity or bleeding.
Nursing Implications
Assessment: Monitor for skin reactions, infusion reactions, electrolyte disturbances, pulmonary status.
Diagnoses:
- Risk for skin impairment
- Risk for infusion reactions
- Electrolyte imbalance
Implementation: Administer as per schedule, monitor infusion closely, assess for adverse effects, correct electrolyte imbalances before therapy.
Evaluation: Assess for reduction in tumor size, monitor blood work, watch for adverse reactions.
Patient/Family Teaching
- Report any signs of allergic reactions, skin rash, or difficulty breathing immediately.
- Maintain hydration and electrolyte balance.
- Protect skin from sun exposure and report severe skin changes.
Special Considerations
Black Box Warnings:
- Serious infusion reactions, dermatologic toxicity, pulmonary events such as interstitial lung disease.
- Potential for promotes tumor escape via mutation in downstream signaling pathways.
Genetic Factors: KRAS mutation status should be determined; only KRAS wild-type tumors respond.
Lab Test Interference: May cause hypomagnesemia, hypocalcemia — monitor electrolytes.
Overdose Management
Signs/Symptoms: Signs of overdose may include severe rash, electrolyte disturbances, or infusion reactions.
Treatment: Supportive care, stop infusion, treat symptoms according to severity; no known specific antidote.
Storage and Handling
Storage: Store refrigerated at 2-8°C, do not freeze.
Stability: Stable for up to 24 hours at room temperature after preparation; use promptly.