Soluble or insoluble Prussian blue for radiocesium and thallium poisoning?

OBJECTIVE: To review the available English-language literature concerning the efficacy of soluble and insoluble Prussian blue used as a therapeutic agent in radiocesium and thallium poisoning. DATA SOURCES: A thorough search of MEDLINE, Toxline, and EMBASE databases (1960s - August 2003) was performed. Search terms included Prussian blue, thallium, and radiocesium poisoning. Bibliographies of relevant papers were reviewed for additional citations. STUDY SELECTION AND DATA EXTRACTION: Reports and studies of human trials and cases, along with animal and relevant in vitro data, were sought. Data were categorized as insoluble and soluble Prussian blue and by thallium and radiocesium poisoning. DATA SYNTHESIS: The majority of evidence describing the efficacy of Prussian blue for radiocesium poisoning is based on the use of the insoluble form. In contrast, the majority of data supporting the efficacy of Prussian blue in thallium poisoning involves the use of the soluble form. CONCLUSIONS: Insoluble Prussian blue has recently been approved in the US for treatment of both thallium and radiocesium poisoning. While there is sufficient evidence that the insoluble form of Prussian blue is effective in radiocesium poisoning, there is a paucity of analogous data supporting its use in thallium poisoning. Whether the physicochemical differences between soluble and insoluble Prussian blue have any effect on outcomes in human poisoning is not known.