Strontium chloride, 89Sr (Solution) Instructions for Use

Marketing Authorization Holder

Federal Center For Design And Development Of Nuclear Medicine Facilities Of The FMBA Of Russia, FSUE (Russia)

Manufactured By

Federal Center For Design And Development Of Nuclear Medicine Facilities Of The FMBA Of Russia, FSUE (Russia)

ATC Code

V10BX01 (Strontium (89Sr) chloride)

Dosage Form

Strontium chloride, 89Sr

Solution for intravenous injection 33.3-40.7 MBq/ml: 150 MBq vial.

Dosage Form, Packaging, and Composition

Solution for intravenous injection transparent, colorless.

Excipients: strontium chloride – 0.2 mg, sodium chloride 9 mg, water for injection up to 1 ml.

150 MBq – vials (1) – transport packaging kit for radioactive substances.

Clinical-Pharmacological Group

Radiopharmaceutical drug for the palliative treatment of bone metastases

Pharmacotherapeutic Group

Radiopharmaceutical therapeutic agent

Pharmacological Action

Strontium chloride, ⁸⁹Sr has a high tropism for bone tissue.

Hyperfixation of the drug is noted in osteoblastic metastatic foci due to its redistribution between healthy bone tissue and foci of the osteoblastic process.

The pharmacokinetic parameters of the drug allow for palliative therapy of pain syndrome in bone metastases.

The drug has an analgesic effect.

Pharmacokinetics

When administered intravenously, the drug accumulates mainly in bone metastases where active osteoblastic processes occur.

It has an analgesic effect.

The fraction of the drug remaining in bone tissues is proportional to the volume of bone metastatic lesion and ranges from 20% to 80% of the administered activity.

Being incorporated into the mineral structure of the affected area, Strontium-89 is not metabolized and remains in it for about 100 days.

Normal bone tissue includes an insignificant part of the administered dose and actively loses it within 14 days.

The excretion of the drug by the kidneys indicates the presence of a bi-exponential curve of unbound strontium-89.

The first phase is the clearance of the drug from the soft tissues of the body, which is completed within the 1st day after injection and amounts to approximately 20% of the total activity of the administered dose.

The second phase is the excretion of the drug from healthy bone tissue, which begins from the 2nd day.

The average value of the total activity excreted in the urine on the 2nd and 3rd days is 8% and 5.5%, respectively.

Indications

As an alternative method or supplement to external radiation therapy for the treatment of pain syndrome in bone metastases of malignant tumors that tend to metastasize to the skeleton

• Hormone-resistant forms of prostate and breast cancer;
• Cancer of the colon, lung, thyroid gland, uterine body, kidney, and skin.

ICD codes

Dosage Regimen

The drug is administered intravenously, slowly, over 1-2 minutes.

The interval between courses is 12 weeks.

For systemic radiation treatment of bone pain syndrome in the presence of single or multiple bone metastases, as well as for metastatic bone lesions in patients with primary tumors of unknown location, a single intravenous administration of Strontium chloride, ⁸⁹Sr solution is performed at an average therapeutic dose of 150 MBq (4.0 mCi).

In patients with excess or deficiency of weight, the calculation is based on 2 MBq/kg of body weight.

Radiation exposure to the patient’s organs and tissues when using the drug Strontium chloride, ⁸⁹Sr

Adverse Reactions

At the moment of drug administration, a reaction in the form of redness of the skin and a sensation of heat may be observed, which resolve on their own within 1-3 minutes.

Some temporary increase in pain syndrome is possible within a few days after drug administration.

During this period, analgesic medications are used to relieve pain.

Leukopenia and thrombocytopenia after 12 weeks with subsequent recovery to baseline values.

Contraindications

• Hypersensitivity, prior therapy with strontium-89 (less than 3 months);
• Patients with a short expected life expectancy (less than 3 months);
• Spinal cord compression (due to metastatic lesion);
• Need for urgent surgical treatment;
• Suppression of bone marrow hematopoiesis (thrombocytopenia – platelets less than 100 thousand/µl, anemia – hemoglobin less than 90 g/l, leukopenia – leukocytes less than 3 thousand/µl, external radiation therapy within the last 4 weeks – depending on blood counts and the need for its urgent implementation);
• Pregnancy, lactation period;
• Children under 18 years of age.

With caution urinary incontinence, urinary tract obstruction requiring catheterization (subject to radiation safety rules when handling urine), presence of diffuse hyperfixation in the bones (increased myelotoxicity due to therapy may be observed), renal failure, concomitant therapy with bisphosphonates or other drugs that reduce Ca2+ exchange (may reduce strontium accumulation).

Use in Pregnancy and Lactation

Contraindicated during pregnancy and lactation.

Use in Renal Impairment

Use with caution in renal failure.

Pediatric Use

Contraindicated in children under 18 years of age.

Special Precautions

The presence of bone metastases must be confirmed by scintigraphic examination of the skeleton before starting treatment.

Since the clinical effect of treatment occurs no earlier than 3-4 weeks, the expected life expectancy should be at least 3 months.

Treatment of the threat of pathological fractures should precede treatment with strontium-89.

Therapy with Ca²⁺ drugs is discontinued 2 weeks before the administration of strontium-89.

After therapy with bisphosphonates or other drugs that reduce Ca²⁺ exchange, confirmation of hyperfixation by scanning before starting therapy with strontium-89 is recommended.

The myelotoxicity index during treatment with the drug can be either minimal or significant due to prior external radiation or chemotherapy.

The likelihood of myelotoxicity due to strontium-89 therapy should be assessed by specialists after careful discussion of the medical history and additional examination data.

A skeletal scan performed within 4 weeks prior to the intended administration of the drug should confirm increased accumulation in the bones, indicating the presence of metastases that are the cause of the pain.

The need to isolate the patient in a separate room after therapy should be decided on a case-by-case basis.

In case of urinary incontinence, bladder catheterization is recommended.

It is recommended to monitor the peripheral blood count before starting therapy and at least once every 2 weeks for 3-4 months.

Treatment should be carried out in a specialized hospital or on an outpatient basis in the department of nuclear medicine or radiation therapy by radiologists trained in the use of radioisotope drugs.

Work with the drug should be carried out in accordance with the “Basic Sanitary Rules for Ensuring Radiation Safety” (OSPORB-99/2010).

Due to the high radiotoxicity of the drug, verification of the dose and the general condition of the patient is mandatory before administration of the drug.

It is necessary to observe safety measures when performing patient personal hygiene to prevent radioactive contamination of the environment and people, including medical personnel.

Overdose

Overdose of the drug is unlikely due to careful control of the administered activity in a medical institution.

Drug Interactions

At the used dosages, interaction with other drugs has not been noted.

Hematotoxic drugs enhance leuko- and thrombocytopenia.

Calcium-containing drugs reduce the distribution of strontium in the mineral structure of the bone; they must be discontinued 2 weeks before strontium administration and resumed 2 weeks after the end of strontium therapy.

Storage Conditions

The drug is stored in compliance with the requirements of OSPORB-99/2010, NRB-99/2009.

Shelf Life

Shelf life – 30 days from the date of manufacture.

Dispensing Status

Dispensed only upon requests to specialized radioisotope laboratories of medical diagnostic institutions.

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.