strontium-89 chloride(redirected from Metastron)
strontium-89 chloride(stron-tee-um) ,
Pregnancy Category: D
ClassificationTherapeutic: nonopioid analgesics
Treatment of bone pain in patients with painful skeletal metastases.
Preferentially taken up by bone tumors and metastatic bone lesions, where selective irradiation takes place.
Decreased pain from bony metastases. Because of delayed onset, adequate analgesia should be provided until effects of strontium are evident.
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.
Time/action profile (pain relief)
|IV||7–20 days||variable||6 mo (range 4–12 mo)|
Contraindicated in: Lactation: Lactation; Obstetric: Pregnancy.
Use Cautiously in: Women with childbearing potential; Pediatric: 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.
Adverse Reactions/Side Effects
- transient increase in bone pain
Drug-Drug interactionAdditive bone marrow toxicity with antineoplastics or previous radiation therapy.Calcium-containing medications may ↓ bone uptake and effectiveness of strontium (discontinue 2 wk prior to strontium; may resume 2 wk after strontium).
Intravenous (Adults) 148 megabecquerels (4 millicuries) or 1.5–2.2 megabecquerels/kg (40–60 microcuries/kg), not to be repeated sooner than 90 days.
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 millicuries) in 10-mL vials
- Assess pain (intensity, location) periodically throughout therapy. Patient may experience a transient increase in bone pain for 2–3 days, beginning 2–3 days after administration. This is normal, and increasing analgesic doses may be required. Pain should begin to diminish after 1–2 wk or longer and may allow for reduction or discontinuation of analgesics. Effects may continue for several months.
- Lab Test Considerations: Monitor hematologic parameters (WBC, platelets) at least once every other week during therapy. Platelets are usually ↓ 30% from preadministration levels. The nadir of thrombocytopenia is 12–16 wk. Leukopenia may also occur. Recovery to preadministration levels usually occurs within 6 mo.
Potential Nursing DiagnosesAcute pain (Indications)
Deficient knowledge, related to medication regimen (Patient/Family Teaching)
- Should be administered only in facilities with personnel experienced in the safe use and handling of radiopharmaceuticals.
- Incontinent patients should have urinary catheters placed prior to administration to minimize the risk of radioactive contamination of clothing, linens, and the environment.
- Administered by slow injection over 1–2 min. A flushing sensation may be experienced following a rapid (<30 sec) injection.
- Instruct patient to continue taking pain medication until strontium-89 becomes effective. Analgesic doses may be decreased once the effects of strontium are known.
- Advise patient that no change in eating or drinking is necessary. Alcohol and caffeine need not be avoided unless advised by health care professional.
- Strontium-89 is present in the blood and urine for 1 wk following injection. During the 1st wk, the patient should be instructed to use a normal toilet rather than a urinal if possible and to flush twice after use. Spilled urine or blood from a cut should be wiped up with a tissue and flushed. Good handwashing should be observed, and any linen contaminated with blood or urine should be immediately washed separately from other items and rinsed thoroughly. If any urine collection device is used, the instructions on its use should be followed.
- Instruct patient not to receive any vaccinations during therapy without consulting health care professional.
- Instruct patient to notify any health care professional or caregiver of strontium-89 therapy prior to treatment.
- Advise patient to contact health care professional if the effects of strontium-89 decrease and pain returns.
- May cause infertility. Counsel patient prior to therapy. Advise female patients to notify health care professional immediately if pregnancy is planned or suspected, or if breastfeeding.
- Emphasize the importance of periodic blood tests.
- Decrease in pain due to bony metastases. Repeat administration is based on patient’s response to therapy, current symptoms, and hematologic status. Repeat doses are not recommended at intervals of <90 days.