How does Prussian blue work?
Prussian blue works using a mechanism known as ion exchange. Cesium or thallium that have been absorbed into the body are removed by the liver and passed into the intestine and are then re-absorbed into the body (entero-hepatic circulation). Prussian blue works by trapping thallium and cesium in the intestine, so that they can be passed out of the body in the stool rather than be re-absorbed. If persons are exposed to radioactive cesium, radioactive thallium, or non-radioactive thallium, taking Prussian blue may reduce the risk of death and major illness from radiation or poisoning. – FDA/Center for Drug Evaluation and Research, “Questions and Answers on Prussian Blue” People may have blue feces (stool) during the time that they are taking Prussian blue. – Centers for Disease Control and Prevention, fact sheet on Prussian blue Finally, essayist Cohen notes, “Tragically, “Prussian Blue” was the first Crayola-brand crayon to be renamed by the company — becoming “Midnight Blue,” in 1958.
