Strontium-89 Chloride

INTRODUCTION

Indications

Treatment of bone pain in patients with painful skeletal metastases.

Action

Preferentially taken up by bone tumors and metastatic bone lesions, where selective irradiation takes place. Therapeutic Effects: Decreased pain from bony metastases. Because of delayed onset, adequate analgesia should be provided until effects of strontium are evident.

Adverse Reactions/Side Effects

Hemat: anemia, neutropenia, thrombocytopenia. MS: transient increase in bone pain.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

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

• Assess any bone pain, and report bone pain that does not resolve spontaneously.

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.

• Implement appropriate manual therapy techniques, physical agents, and therapeutic exercises as indicated to help reduce bone pain and decrease the need for analgesic medications.

• Implement assistive devices (walker, cane, wheelchair) as needed to help protect metastatic bone lesions and prevent fractures.

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.

Distribution: Selectively localized in and retained by metastatic bone lesions. Excreted in breast milk.

Metabolism and Excretion: 67% excreted in urine, 33% in feces.

Half-life: (physical half-life) 50.5 days.

Contraindications/Precautions

Contraindicated in: Lactation; Pregnancy.

Use Cautiously in: Women with childbearing potential; Children <18 yr (safety not established); Patients with platelet counts <60,000 mm³ or WBCs <2400 mm³; Diminished bone marrow reserve or other chronic debilitating illness; Patients with a life expectancy <1–3 wk.

Interactions

Drug-Drug: Additive bone marrow toxicity with antineoplastics or previous radiation therapy. Calcium-containing medications may decrease bone uptake and effectiveness of strontium (discontinue 2 wk prior to strontium; may resume 2 wk after strontium).

Route/Dosage

IV (Adults): 148 megabecquerels (4 millicuries) or 1.5–2.2 megabecquerels/kg (40–60 microcuries/kg), not to be repeated sooner than 90 days.

Availability

Radioactive injection: 10.9–22.6 mg/mL (148 megabecquerels or 4 millicuries) in 10-mL vials, 13.4–20.1 mg/mL (150 megabecquerels or 4.05 ...