Drug Guide
Radium Ra-223 Dichloride
Classification
Therapeutic: Radiopharmaceutical for cancer treatment
Pharmacological: Alpha particle emitting radiopharmaceutical
FDA Approved Indications
- Treatment of castration-resistant prostate cancer with symptomatic bone metastases and no known visceral metastatic disease
Mechanism of Action
Radium Ra-223 mimics calcium and localizes to areas of increased bone turnover, delivering targeted alpha particle radiation to bone metastases, leading to cell death and delay in disease progression.
Dosage and Administration
Adult: 55 kBq/kg IV every 4 weeks for 6 injections
Pediatric: Not approved for pediatric use
Geriatric: No specific dose adjustment necessary based on age alone
Renal Impairment: Use with caution; no specific adjustment recommended
Hepatic Impairment: No specific adjustment necessary
Pharmacokinetics
Absorption: Rapid after IV administration
Distribution: Binds to areas of increased bone turnover
Metabolism: Minimal hepatic metabolism; primarily local action in bone
Excretion: Excreted via feces (primarily), and minimal urinary excretion
Half Life: 11.4 days (alpha emission decays rapidly within tissue)
Contraindications
- Hypersensitivity to radium Ra-223 dichloride or its components
Precautions
- Bone marrow suppression, severe myelosuppression, concurrent treatment with bone marrow suppressing agents, or any other condition that would impair bone marrow function
Adverse Reactions - Common
- Diarrhea (Common)
- Vomiting (Common)
- Bone pain (Common)
- Hematologic adverse events (anemia, thrombocytopenia, neutropenia) (Common)
Adverse Reactions - Serious
- Myelosuppression leading to anemia, thrombocytopenia, neutropenia (Serious)
- Secondary malignancies (rare) (Rare)
Drug-Drug Interactions
- Bone marrow suppressants, other radiopharmaceuticals
Drug-Food Interactions
- None specific
Drug-Herb Interactions
- None established
Nursing Implications
Assessment: Baseline blood counts, renal and liver function, bone pain evaluation
Diagnoses:
- Risk for infection secondary to myelosuppression
- Impaired tissue integrity related to bone metastases
Implementation: Administer IV as prescribed, monitor blood counts regularly, educate patient on signs of hematologic toxicity, encourage hydration
Evaluation: Monitor for adverse effects, assess effectiveness via symptom relief and disease progression
Patient/Family Teaching
- Report any signs of infection, bleeding, or unusual symptoms promptly
- Maintain hydration and good hygiene
- Avoid contact with pregnant women or children during treatment
Special Considerations
Black Box Warnings:
- Myelosuppression and increased risk of secondary hematologic malignancies
Genetic Factors: No specific genetic testing indicated
Lab Test Interference: Bone marrow suppression may affect blood test results
Overdose Management
Signs/Symptoms: Bone marrow suppression, severe cytopenias
Treatment: Supportive care, blood transfusions, growth factor support as needed, hospitalization if severe
Storage and Handling
Storage: Store in a secure place at controlled room temperature, away from children and pregnant women
Stability: Stable until expiry date on the label, follow manufacturer instructions for handling