The world of clinical toxicology is a minefield of case studies, anecdotes and opinions. Rarely is there a randomized control study anywhere to be found. The ethics of poisoning someone, randomizing them to a treatment or no treatment arm and recording results is apparent. That study is extremely difficult to design.
The Extracorporeal Treatment in Poisoning (EXTRIP) is a group of toxicologists, pharmacologists, nephrologists and others who are developing guidelines on the treatment of a variety of toxins. Their work on lithium and valproate intoxication was fascinating. The groups reviewed all the existing literature, over 1,200 papers, as background to a evidence based guideline. They readily dismissed most papers and closely evaluated around 130 for each guideline. How many were randomized controlled trials? none. The definitive treatment for lithium toxicity is hemodialysis. Yet there is not a single trial to demonstrate benefit.
In August 2011 a new antivenom for the treatment of scorpion stings received FDA approval. The approval was partially based on a single randomized control trial in Tucson. Fifteen children were enrolled and eight received antivenom. Fascinating. Of interest is that no other hospital in Arizona would take on the study due to ethical concerns. And when the study showed the new antivenom to be a resounding success, they could not ethically continue the trial. How can you give a placebo to a child when you know there is a proven successful treatment.
Randomized controlled trials in toxicology. It is a world befuddled by ethical concerns and a desire to do the best for unfortunate patients.
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