Selenium Overdose Caused Deaths of Polo Horses

tags: , , , , , , ,

A Lechuza pony stands ready for play.

Image: New York Social Diary (2008).

The mysterious deaths of twenty-one Venezuelan polo horses was apparently due to a mistake by the pharmacy that incorrectly prepared the vitamin-and-electrolyte cocktail that was injected into these horses prior to their match on Sunday. A chemist at Franck's Pharmacy in Ocala, Florida added ten times the requested dosage of selenium to the cocktail. It appears this was an error and not the result of foul play.

The cocktail injected into the Lechuza Caracas horses was based on a commercial supplement called Biodyl. It is a vitamin and mineral supplement made in France, and is widely used there and in other countries, but it has never been approved for use in the US.

Biodyl is advertized as "the power booster" because it supposedly aids recovery from fatigue.

"When you talk about polo ponies, we consider them equine athletes," said Don Dufresne, who describes himself as an equine legal expert and horse lover. "A horse is so important to your game as a player, you want the horses to be as healthy as they can be, to last as long as they can. You don't want to overexert a horse. A tired horse is an unsafe horse."

Apparently, injected vitamin and mineral supplements are commonly used in the performance horse industry in the United States to prevent muscle cramps and help them recover after the events.

"Supplements are used to maintain the levels of electrolytes in the body," said Loyd V. Allen, Jr., editor of the International Journal, Pharmaceutical Compounding. "There is a lot of energy expended during those matches and that puts additional stress [on the horses]. It's just to help to keep things where they should be."

But mimicking the formulation of an unapproved supplement appears to violate federal law, according to FDA officials, because compounding pharmacies are only allowed to reproduce drugs that are unavailable in the United States in an emergency.

"The pirated drugs can present a risk to horses because they don't go through the FDA approval process," said Dr. Eleanor Green, dean of Texas A&M University's veterinary college and past president of American Association of Equine Practitioners. "So there's no way to know for sure that it contains the right drug or the right amount of the drug."

Biodyl is given to high performance horses several days prior to a race or other strenuous event. According to a Biodyl website, this supplement contains vitamin B12 (cyanacobalamin), adenosine triphosphoric acid (ATP), potassium (potassium aspartate hemihydrate), magnesium (magnesium aspartate tetrahydrate) and selenium (sodium selenite). It is administered either in drinking water or by injection into either the muscles (IM) or a vein (IV).

Anonymous sources told La Nación, the national Argentinian newspaper, that the veterinarian's prescription requested 0.5 mg of sodium selenite per milliliter of the cocktail, but the chemist added 5 mg, or ten times that amount. According to the National Research Council, a single minimal lethal oral dose of sodium selenite in horses is 3.3 mg/kg, but a fatal injected preparation, such as what these horses received, contains a much smaller concentration.

"Horses need selenium. It's in their diet, said Dr. Green. "But in general selenium in high doses can be toxic."

Selenium is a naturally-occurring mineral that is essential to good health in tiny amounts, but it is fatal in large doses. Symptoms of selenium poisoning include pulmonary edema, reduced blood pressure, unconsciousness and death -- which are consistent with the symptoms observed in the stricken polo horses.

Franck's Pharmacy, which also compounds drugs for people, will probably be sued.

"Everybody wants to ensure that what their horses are getting is correct and is not going to harm their horse. I thing everybody is going to become more aware of this and more cautious."

The FDA has not yet commented on the pharmacy's revelation.

Sources:

Biodyl the power booster.

CNN News.

More like this

Let's not jump to the typical FDA conclusion that this is due to illegal compounding. This was a DISPENSING ERROR, no different than if a pharmacist dispensed a so-called "approved FDA drug" but used the wrong strength. It would not have prevented this tragedy, since it is a "procedural" error as opposed to it being compounded. If the prescription was filled as prescribed by the practitioner, this would all be moot. Keep the comments focused on the CAUSE, not the corollary issues.

There is NO EXCUSE for this mistake. These pharmacists are dealing with all kinds of chemicals that can potentially cause death when misdispensed. This is a fundamental skill of a chemistry student in college to know the importance of attention to measurements (for EACH and EVERY measurement). Whatever the root flaw was in this tragedy(paperwork, lack of chemical verification, lack of attention, etc.), it is INEXCUSABLE and MANY people need to be held responsible for this. My heart goes out to those closest to the fallen horses. Such a tramatic and undeserved experience for a team who honorably cares for their horses.

No-one takes ANY type of error lightly. While many may feel that pharmacists should not be permitted to make errors since their training warns them that errors cannot be condoned given the consequences on a patient's health, the reality is that there is a strong movement by licensing bodies, especially in Canada, to NOT view a dispensing error as one of the most grievous misconduct acts a pharmacist could ever do. (Ref: see www.ocpinfo.com and look at the "Discipline cases" under "For the Public" dropdown menu).
Some practitioners state that if anyone says they've never made an error, they're lying. Not true. Many make errors but CATCH them in their quality assurance/quality control processes before they leave the store (and thus, are not dispensing errors).
While humans will always have the potential to make errors, the impact of such errors must factor into the ultimate penalty. To take the position universally, however, that "an error does not constitute misconduct" (as a general tenet) is the worst thing a licensing body can do.

There is no need to use sodium selenite. There are forms of organic Selenium, which cannot be overdozed by definition, such as Selenium Yeast or the active compound contained in them, which is Selenomethionine. Using inorganic Selenium selenite is a poor man's practice, which is really odd on highly prized horses. It's like trying to cure syphilis by a Mercury bath, as they did in the Middle ages. I would blame the vet for backwardness.

By Dennis Tranquil (not verified) on 29 Apr 2009 #permalink

"Anonymous sources told La Nación, the national Argentinian newspaper, that the veterinarian's prescription requested 0.5 mg of sodium selenite per milliliter of the cocktail, but the chemist added 5 mg, or ten times that amount."
No. It is the same amount, which demonstrates, of course, how easy it is to mistake "mcg" for "mg."

By G. B. Arbuckle (not verified) on 19 May 2009 #permalink