Lapatinib

INTRODUCTION

Indications

Advanced metastatic breast cancer with tumor overexpression of the human epidermal receptor type 2 (HER2) and past therapy with an anthracycline, a taxane, and trastuzumab; used in combination with capecitabine (Xeloda).

Action

Acts as an inhibitor of intracellular tyrosine kinase affecting epidermal growth factor (EGFR, ErbB1) and HER2 (ErbB2). Inhibits the growth of ErbB-driven tumors. Effect is additive with capecitabine. Therapeutic Effects: Decreased/slowed spread of metastatic breast cancer.

Adverse Reactions/Side Effects

CNS: fatigue, insomnia. Resp: dyspnea, interstitial lung disease, pneumonitis. CV: ↓ left ventricular ejection fraction. GI: HEPATOTOXICITY, diarrhea, nausea, vomiting, dyspepsia, ↑ liver enzymes, stomatitis. Derm: palmar-plantar erythrodysesthesia, rash, dry skin. Hemat: neutropenia. MS: back pain, extremity pain.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Be alert for signs of hepatotoxicity, including anorexia, abdominal pain, severe nausea and vomiting, yellow skin or eyes, fever, sore throat, malaise, weakness, facial edema, lethargy, and unusual bleeding or bruising. Report these signs to the physician or nursing staff immediately.

• Assess any breathing problems and signs of pneumonitis or interstitial lung disease. Signs include dry cough, wheezing, chest pain, shortness of breath, and difficult or labored breathing. Monitor pulse oximetry and perform pulmonary function tests (See Appendices I, J, K) to quantify suspected changes in ventilation and respiratory function.

• Be alert for palmer-planter erythrodysesthesia, as indicated by pain, redness, and dry, scaly skin on the palms of the hands and soles of the feet. Report these signs to the physician or nursing staff. Instruct patient also to protect the hands and feet from heat and friction, and to apply lotion to the affected areas. Superficial cold application can also temporarily reduce symptoms.

• Monitor signs of neutropenia, including fever, sore throat, and other signs of infection. Report these signs to the physician or nursing staff.

• Assess any back or extremity pain to rule out musculoskeletal pathology; that is, try to determine if pain is drug induced rather than caused by anatomic or biomechanical problems.

Interventions

• For patients who are medically able to begin exercise, implement appropriate resistive exercises and aerobic training to maintain muscle strength and aerobic capacity during cancer chemotherapy or to help restore function after chemotherapy.

• Because of potential cardiac problems (decreased left ventricular function) and pulmonary toxicity, use caution during aerobic exercise and endurance conditioning. Terminate exercise if patient exhibits untoward symptoms (chest pain, shortness of breath, unusual fatigue) or displays other criteria for exercise termination (See Appendix L).

Patient/Client-Related Instruction

• Advise patient to guard against infection (frequent hand washing, etc.), and to avoid crowds and contact ...