Pemetrexed

INTRODUCTION

Indications

Malignant pleural mesothelioma (with cisplatin) when tumor is unresectable or patient is not a candidate for surgery. Local advanced or metastatic non–small-cell lung cancer in previously treated patients.

Action

Disrupts folate-dependent metabolic processes involved in thymidine and purine synthesis. Converted intracellularly to polyglutamate form which increases duration of action. Therapeutic Effects: Decreases growth and spread of mesothelioma.

Adverse Reactions/Side Effects

Resp: pharyngitis. CV: chest pain. GI: constipation, nausea, stomatitis, vomiting, anorexia, diarrhea, esophagitis, mouth pain. Derm: desquamation, rash. Hemat: anemia, leukopenia, thrombocytopenia. Neuro: neuropathy. Misc: fever, infection.

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 or nursing staff.

• Assess numbness, tingling, or weakness that might indicate peripheral neuropathy. Establish baseline electroneuromyographic values using EMG and nerve conduction at the beginning of drug treatment whenever possible. Periodically reexamine these values to document drug-induced changes in peripheral nerve function.

• Monitor any chest pain, and assess heart rate (HR) and blood pressure (BP) whenever patient experiences symptoms (See Appendices F, G). Refer patients with abnormal HR or BP responses or prolonged and persistent chest pain to the physician for further evaluation.

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

• Instruct patient to decrease risk of infections (frequent hand washing, etc.), and to avoid contact with persons with contagious diseases.

• Advise patient about the likelihood of GI reactions, including nausea, vomiting, diarrhea, constipation, loss of appetite, heartburn, and pain/inflammation in or around the mouth. Instruct patient to report severe or prolonged GI problems.

• Advise patient that rash, exfoliation, and other skin reactions are likely. Report severe or unexpected skin reactions to the physician.

• Instruct patient and family/caregivers to report other side effects such as severe or prolonged fever, upper respiratory tract inflammation, or signs of infection.

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.

Distribution: Unknown.

Metabolism and Excretion: Minimal metabolism; 70–90% excreted unchanged in urine.

Half-life: 3.5 hr (normal renal function).