panitumumab


panitumumab

(pan-i-tu-mu-mab) panitumumab,

Vectibix

(trade name)

Classification

Therapeutic: antineoplastics
Pharmacologic: monoclonal antibodies
Pregnancy Category: C

Indications

Treatment of metastatic colorectal cancer that expresses EGFR (epidermal growth factor receptor) and has failed conventional treatments (to be used as monotherapy).

Action

genetic implication Binds to EGFR resulting in inactivation of kinases that regulate proliferation and transformation.

Therapeutic effects

Decreased progression of colorectal cancer.

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.Distribution: Monoclonal antibodies cross the placenta and enter breast milk.Metabolism and Excretion: Unknown.Half-life: 7.5 days.

Time/action profile

ROUTEONSETPEAKDURATION
IVunknownend of infusionunknown

Contraindications/Precautions

Contraindicated in: Concurrent leucovorin;genetic implication Patients whose tumors have KRAS mutations in codon 12 or 13 (not effective); Obstetric / Lactation: Pregnancy or lactation.Use Cautiously in: Pediatric: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

  • fatigue (most frequent)

Ear, Eye, Nose, Throat

  • ocular toxicity (life-threatening)
  • eyelash growth

Respiratory

  • pulmonary fibrosis (life-threatening)
  • cough (most frequent)

Gastrointestinal

  • abdominal pain (most frequent)
  • constipation (most frequent)
  • diarrhea (most frequent)
  • nausea (most frequent)
  • vomiting (most frequent)
  • stomatitis

Dermatologic

  • necrotizing fasciitis (life-threatening)
  • paromychia (most frequent)
  • abscesses
  • dry skin
  • erythema
  • photosensitivity
  • pruritis
  • rash
  • skin fissures

Fluid and Electrolyte

  • edema (most frequent)
  • hypocalcemia
  • hypomagnesemia (most frequent)

Miscellaneous

  • infusion reactions (life-threatening)
  • sepsis (life-threatening)

Interactions

Drug-Drug interaction

None noted.

Route/Dosage

Intravenous (Adults) 6 mg/kg as a 60-min infusion every 14 days; ↓ infusion rates and dose modifications are recommended for infusion reactions and other serious toxicities.

Availability

Solution for IV administration (requires dilution): 20 mg/mL

Nursing implications

Nursing assessment

  • Assess for dermatologic toxicity (dermatitis acneiform, pruritus, erythema, rash, skin exfoliation, paronychia, dry skin, skin fissures). If severe, may lead to infection (sepsis, septic death, abscesses requiring incision and drainage). With severe reactions, withhold panitumumab and monitor for inflammatory or infectious sequelae.
  • Monitor for severe infusion reactions (anaphylactic reaction, bronchospasm, fever, chills, hypotension). If severe reaction occurs, stop panitumumab; may require permanent discontinuation.
  • Assess for pulmonary fibrosis (cough, wheezing, exertional dyspnea, interstitial lung disease, pneumonitis, lung infiltrates). Permanently discontinue panitumumab if these signs occur.
  • Monitor for diarrhea during therapy.
  • Lab Test Considerations: Monitor electrolyte levels periodically during and for 8 wk after completion of therapy. May cause hypomagnesemia and hypocalcemia.

Potential Nursing Diagnoses

Risk for impaired skin integrity (Adverse Reactions)
Impaired gas exchange (Adverse Reactions)

Implementation

  • Intermittent Infusion: Diluent: Withdraw necessary amount of panitumumab. Dilute to a volume of 100 mL with 0.9% NaCl; dilute doses >1000 mg with 150 mL.Concentration: 10 mg/mL. Mix by inverting gently; do not shake. Administer via infusion pump using a low-protein binding 0.2 mcg or 0.22 mcg in-line filter. Solution is colorless and may contain a small amount of visible translucent to white, amorphous, proteinaceous particles. Do not administer solutions that are discolored or contain particulate matter. Store in refrigerator; do not freeze. Use diluted solution within 6 hr of preparation if stored at room temperature or within 24 hr if refrigerated.
  • Rate: Administer over 60 min every 14 days. Administer doses >1000 mg over 90 min.
    • If mild to moderate infusion reaction (Grade 1 or 2) occurs decrease infusion rate by 50%. If severe reaction (Grade 3 or 4) occurs, immediately and permanently discontinue panitumumab.
    • If severe dermatologic toxicities (Grade 3 or higher) or those considered intolerable occur, withhold panitumumab. If toxicity does not improve to ≤ grade 2 within 1 mo, discontinue permanently. If toxicity improves to ≤ grade 2 and patient improves symptomatically after withholding no more than 2 doses, resume therapy at 50% dose. If toxicities recur, permanently discontinue panitumumab. If toxicities do not recur, increase subsequent doses in 25% increments of the original dose until recommended dose of 6 mg/kg is reached.
  • Y-Site Incompatibility: Flush line before and after administration with 0.9% NaCl. Do not mix with other medications or solutions.

Patient/Family Teaching

  • Explain purpose of panitumumab to patient.
  • May cause photosensitivity. Caution patient to wear sunscreen and hats and to limit sun exposure.
  • Advise patient to notify health care professional if signs and symptoms of dermatologic toxicity, infusion reactions, pulmonary fibrosis, or ocular changes occur.
  • Advise patient that panitumumab may cause fertility impairment and may have teratogenic effects. Caution women of childbearing yr to use contraception during and for at least 6 mo after the last dose and not to breast feed during and for at least 2 mo after the last dose of panitumumab. Encourage women who become pregnant to enroll in Amgen’s Pregnancy Surveillance Program by calling 1-800-772-6436.
  • Emphasize the need for periodic blood tests to monitor electrolyte levels.

Evaluation/Desired Outcomes

  • Decreased progression of colorectal cancer.