Colchicine: be afraid, be very afraid

July 4, 2010, 1:29 pm

★★★★★

Colchicine poisoning: the dark side of an ancient drug. Finkelstein Y et al. Clin Toxicol 2010;48:407-414.

Abstract

I’ve always thought that colchicine was an awful drug, and that the recommendations for its use in the emergency department didn’t make sense.

Let me explain.  Colchicine is a feared poison — it impairs the function of cellular microtubules, interfering with essential processes such as mitosis, secretion, protein synthesis, and myocardial function. Even small doses can result in multi0organ failure, and no antidote is available.  Onset of life-threatening toxicity can be heralded by severe gastrointestinal symptoms. Yet here is what Rosen’s Emergency Medicine had to say about the management of gout:

“The oral dose regiment [of colchicine] is 0.6 mg orally every hour until the pain is controlled, up to a maximum of 6 mg or until side effects supervene.  Patients may have severe nausea and vomiting or diarrhea from oral colchicine.”

If the patient has renal dysfunction, is taking any one of a number of specific medications that interfere with colchicine metabolism, or doesn’t understand precisely how to take the medication  — how often does that happen? — the chance for disaster increases.  And as the authors of this superb review of colchicine toxicity point out, the drug has a low therapeutic index with no specific demarcation between nontoxic, toxic, and lethal doses.  In addition, severe gastrointestinal symptoms may occur before pain relief in up to 91% of patients with gout.  As they (under)state: “The suggestion to administer colchicine at frequent intervals until gastrointestinal side effects develop is a matter of significant concern and has led to unintentional death . . .”

This article comprehensively reviews all aspects of colchicine toxicity, has 113 references, and is a must-read.

Last year in Emergency Medicine News I discussed a medical-legal case in which the ill-advised use of colchicine to treat gout ended in fatality.

Full disclosure: Steve Aks, one of the co-authors of this review, is a friend and a member of our toxicology group.  In 2000, we attended game 3 of the World Series at Shea Stadium — the “Subway Series”.  The Mets defeated the Yankees 4-2, breaking the perfect post-season record of pitcher Orlando “El Duque” Hernandez. Unfortunately, it was the only game the Mets won.

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