Cetuximab is believed to bind to the natural protein epidermal growth factor receptor (EGFR) found on the surface of cancer cells, inhibiting cell growth. It is derived from both mouse and human antibodies.

Loading dose of 400 mg/m² given IV infusion over 2 hrs. If tolerated, patients given weekly dose of 250 mg/m² over 60 minutes. Maximum rate is 5 ml/min.

May be given alone or in combination with irinotecan in the treatment of colorectal cancer. Adjuvant therapy with radiation therapy for locally advanced head and neck cancer and as a single agent in patients who have failed chemotherapy. Effective only in patients who test positive for the HER1 protein.

A risk exists of severe infusion reaction (bronchospasm, stridor, urticaria, and hypotension), usually occurring with the first dose. Dermatologic toxicity (including acneform rash, skin drying and fissuring, and inflammatory and infectious sequelae) may be severe. Less common side effects include weakness, fever, nausea, constipation, diarrhea, and abdominal pain.

In studies, a small number of patients developed interstitial lung disease (ILD), including difficulty breathing and low blood pressure. Etiology is unclear.

Prepare emergency equipment and medications prior to starting infusion. Premedication with H₁ antagonist (diphenhydramine 50 mg IV) is recommended. Severe infusion reactions require immediate interruption of infusion and permanent discontinuation of further treatment.

Medication should be delivered through an inline 0.22-micrometer filter placed as proximal to the patient as practical. Prime tubing with cetuximab and flush with 0.9% saline solution after infusion. Cetuximab should be piggybacked to the patient's infusion line. A one-hour observation period is recommended following infusion. Longer observation periods may be required in patients who experience infusion reactions.

Sunlight may exacerbate skin reactions. Patients should limit sun exposure, wearing sunscreen and hats. Monitor for infectious sequelae of dermatologic toxicities.

Patients developing pulmonary disorders should be investigated promptly. If ILD develops, cetuximab should be discontinued and patient treated appropriately.

Monitor for hypomagnesemia and accompanying hypocalcemia and hypokalemia, during and following completion of therapy.