"The US Food and Drug Administration (FDA) today approved asfotase alfa (Strensiq, Alexion Pharmaceuticals) as the first-ever therapy for patients who develop hypophosphatasia, a rare metabolic bone disorder, in childhood.
Metastron (Strontium-89 Chloride Injection) is indicated for the relief of bone pain in patients with painful skeletal metastases.
The presence of bone metastases should be confirmed prior to therapy.
DOSAGE AND ADMINISTRATION
The recommended dose of Metastron is 148 MBq, 4 mCi, administered by slow intravenous injection (1-2 minutes). Alternatively, a dose of 1.5 -2.2 MBq/kg, 40-60 μCi/kg body weight may be used.
Repeated administrations of Metastron should be based on an individual patient's response to therapy, current symptoms, and hematologic status, and are generally not recommended at intervals of less than 90 days.
The patient dose should be measured by a suitable radioactivity calibration system immediately prior to administration.
The estimated radiation dose that would be delivered over time by the intravenous injection of 37 MBq, 1 mCi of Strontium-89 to a normal healthy adult is given in Table 4. Data are taken from the ICRP publication “Radiation Dose to Patients from Radiopharmaceuticals”-ICRP #53, Vol. 18, No. 1-4, Page 171, Pergamon Press, 1988.
Table 4: Strontium-89 Dosimetry
|Red Bone Marrow||11.0||40.7|
|Lower Bowel Wall||4.7||17.4|
When blastic osseous metastases are present, significantly enhanced localization of the radiopharmaceutical will occur with correspondingly higher doses to the metastases compared with normal bones and other organs.
The radiation dose hazard in handling Strontium-89 Chloride injection during dose dispensing and administration is similar to that from phosphorus-32. The beta emission has a range in water of about 8 mm (max.) and in glass of about 3 mm, but the bremsstrahlung radiation may augment the contact dose.
Measured values of the dose on the surface of the unshielded vial are about 65 mR/minute/mCi.
It is recommended that the vial be kept inside its transportation shield whenever possible.
Metastron is supplied in a 10 mL vial containing 148 MBq, 4 mCi. The vial is shipped in a transportation shield with approximately 3 mm lead wall thickness, package insert, and two therapeutic agent warning labels.
The vial and its contents should be stored inside its transportation container at room temperature 15°-25°C (59°-77°F).
The calibration date (for radioactivity content) and expiration date are quoted on the vial label. The expiration date will be 28 days after calibration. Stability studies have shown no change in any of the product characteristics monitored during routine product quality control over the period from manufacture to expiration.
This radiopharmaceutical is licensed by the Illinois Emergency Management Agency for distribution to persons licensed pursuant to 32 IL. Adm. Code 330.260(a) and Part 335 Subpart F.335.5010 or under equivalent licenses of the USNRC or an Agreement State.
Manufactured by: GE Healthcare Ltd., HP7 9LL UK GE Healthcare, Medi-Physics, Inc., Arlington Heights, IL 60004 U.S.A. Revised December 2013This monograph has been modified to include the generic and brand name in many instances.
Last reviewed on RxList: 1/24/2014
Additional Metastron Information
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