Palonosetron

INTRODUCTION

Indications

Prevention of acute and delayed nausea and vomiting caused by initial or repeat courses of moderate or highly emetogenic chemotherapy (intravenous). Prevention of acute nausea and vomiting caused by initial or repeat courses of moderately emetogenic chemotherapy (oral). Prevention of postoperative nausea and vomiting (PONV) for up to 24 hr after surgery (intravenous).

Action

Blocks the effects of serotonin at receptor sites (selective antagonist) located in vagal nerve terminals and in the chemoreceptor trigger zones in the CNS. Therapeutic Effects: Decreased incidence and severity of nausea and vomiting following emetogenic chemotherapy or surgery.

Adverse Reactions/Side Effects

CNS: dizziness, headache. GI: constipation, diarrhea.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Monitor improvements in GI symptoms (decreased nausea and vomiting, increased appetite) to help document whether drug therapy is successful.

• Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.

Patient/Client-Related Instruction

• Instruct patient to report bothersome side effects such as severe or prolonged headache or GI problems (diarrhea, constipation).

Pharmacokinetics

Absorption: IV administration results in complete bioavailability; oral bioavailability = 97%.

Distribution: Unknown.

Metabolism and Excretion: 50% metabolized; 40% excreted unchanged in urine.

Half-life: 40 hr.

Contraindications/Precautions

Contraindicated in: Hypersensitivity; cross-sensitivity with other 5-HT₃ antagonists may occur; Lactation: Lactation.

Use Cautiously in: OB/Pedi: Safety not established.

Interactions

Drug-Drug: None significant.

Route/Dosage

IV (Adults): Prevention of chemotherapy-induced nausea/vomiting—0.25 mg 30 min before start of chemotherapy; Prevention of PONV—0.075 mg given immediately before induction of anesthesia.

PO (Adults): 0.5 mg 1 hr before start of chemotherapy.

Availability

Solution for IV injection: 0.075 mg/1.5 mL, 0.25 mg/5 mL. Capsules: 0.5 mg.