Topotecan

INTRODUCTION

Indications

IV: Metastatic ovarian cancer that has not responded to previous chemotherapy. Small-cell lung cancer unresponsive to 1st-line therapy. PO: Relapsed small-cell lung cancer in patients with a complete or partial prior response and who are at least 45 days from the end of 1st-line chemotherapy. Stage IV-B persistent or recurrent cervical cancer not amenable to treatment with surgery or radiation (with cisplatin).

Action

Interferes with DNA synthesis by inhibiting the enzyme topoisomerase. Therapeutic Effects: Death of rapidly replicating cells, particularly malignant ones.

Adverse Reactions/Side Effects

CNS: headache, fatigue, weakness. Resp: dyspnea. GI: abdominal pain, diarrhea, nausea, vomiting, anorexia, constipation, increased liver enzymes, stomatitis. Derm: alopecia. Hemat: anemia, leukopenia, thrombocytopenia. MS: arthralgia.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Watch for signs of leukopenia (fever, sore throat, signs of infection), thrombocytopenia (bruising, nose bleeds, bleeding gums), or unusual weakness and fatigue that might be due to anemia. Report these signs to the physician.

• Assess respiratory symptoms such as difficult or labored breathing. Monitor pulse oximetry and perform pulmonary function tests (See Appendix I) to quantify suspected changes in ventilation and respiratory function.

• Assess any joint 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.

Patient/Client-Related Instruction

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

• Advise patient about the likelihood of GI reactions (nausea, vomiting, diarrhea, constipation, loss of appetite, irritation in/around the mouth). Instruct patient or family and caregivers to also report 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.

• Advise patient and family/caregivers that fatigue and weakness are likely and may be severe. Functional abilities may be limited, and patient may need to use assistive devices during ambulation.

• Advise patient that hair loss is likely. Instruct patient to report severe or unexpected skin problems.

• Instruct patient or family/caregivers to report other bothersome side effects such as severe or prolonged headache.

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.

Distribution: Unknown.

Metabolism and Excretion: 30% excreted in urine; ...