In the past I’ve blogged about lethal radioactive chemicals (here and here) as possible murder weapons to use in your murder mysteries and thrillers. There is another rather dramatic radioactive agent—a beneficial medication at that—which could take center stage in the development of your next lethal plot.

Samarium is a radioisotope drug used to treat the pain associated with bone cancer. The treatment is more palliative than curative—that is, it increases a patient’s comfort level by decreasing the pain associated with metastatic bone cancer but does not cure the disease. The drug is often one of several treatments used for patients with lung, prostate and breast cancers—as well as those with osteosarcoma.

The chemical, named samarium Sm 153 lexidronam, has an interesting molecular structure such that the body treats the chemical like calcium and selectively uptakes the drug into the body’s skeletal structure like it would calcium. Once administered, the drug is distributed throughout the body before it is absorbed into bones, where it remains.

What makes this pharmaceutical such a great murder weapon is that it’s given intravenously in a clinical setting such as a hospital, and therefore it’s relatively easy to obtain for the creative villain. There are more than 10,000 hospitals worldwide that use radioisotopes in medical treatments. Therefore, it’s a good bet that a hospital clinic that treats metastatic bone cancer would have samarium-153 on hand.

The drug emits both radioactive beta particles (the therapeutic part) and gamma rays (which make it easier to locate in the body). As with other radioactive chemicals, larger than therapeutic doses can be lethal. In one of the episodes of the television drama Law and Order Criminal Intent, a person is murdered by unknowingly ingesting three vials of samarium-153.

Samarium is available as a preservative-free solution that is clear, colorless to slight amber in color, and comes in 10-ml vials that must remain frozen until used. The drug expires (technically, its therapeutic half life) within 48 hours after being removed from the freezer.

The side effects of an overdose can be dramatic. The initial symptoms include dizziness, fatigue, joint aches, fever, chills, cough and a sore throat—in other words, flu-like symptoms occur early on that can mask the detection of a victim being poisoned until it’s too late. The symptoms progress to noticeable heart rhythm abnormalities, breathing difficulties, tingling or numbness of the extremities, excessive nosebleeds and internal bleeding that can exhibit as blood in the urine.

Certainly, this prescription drug is of great benefit to the medical community, but it can also be an exceptionally useful tool for the murder mystery writer with a creative, and possibly devious, mind.

Thoughts? Comments? I’d love to hear them!