Samarium (¹⁵³Sm) lexidronam (chemical name Samarium-153-ethylene diamine tetramethylene phosphonate, abbreviated Samarium-153 EDTMP, trade name Quadramet) is a chelated complex of a

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

of the element

samarium Samarium is a chemical element with symbol Sm and atomic number 62. It is a moderately hard silvery metal that slowly oxidizes in air. Being a typical member of the lanthanide series, samarium usually has the oxidation state +3. Compounds of samar ...

with EDTMP. It is used to treat pain when

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

has spread to the

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

. It is injected into a vein and distributed throughout the body, where it is preferentially absorbed in areas where cancer has invaded the bone. The radioisotope ¹⁵³Sm, with a

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ...

of 46.3 hours, decays by emitting

beta particles A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay. There are two forms of beta decay, β ...

(

electrons The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have n ...

), which kill the nearby cells. Pain begins to improve in the first week for most people and the effects can last several months. It is commonly used in

lung cancer Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. Lung carcinomas derive from transformed, mali ...

prostate cancer Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that su ...

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or ...

, and

osteosarcoma An osteosarcoma (OS) or osteogenic sarcoma (OGS) (or simply bone cancer) is a cancerous tumor in a bone. Specifically, it is an aggressive malignant neoplasm that arises from primitive transformed cells of mesenchymal origin (and thus a sarcoma ...

Side effects

Side effects include the following: *Black, tarry stools *Blood in urine/stool *Cough, hoarseness *Fever/chills *Lower back/side pain *Painful or difficult urination *Pinpoint red spots on skin *Irregular heartbeat *Nausea, vomiting

Supply and administration

Samarium lexidronam is supplied as a frozen solution for intravenous use with an activity of 50±5 mCi/mL on Quadramet. 2009. and a maximum beta energy of 0.808 MeV. Due to the short half-life of the radioisotope, the drug expires 56 hours after the noted calibration time.

References

Radiopharmaceuticals Samarium compounds Phosphonates Coordination complexes Tertiary amines {{pharma-stub