Equioxx vs. Previcox: What you need to know

By: Katie Jones, CVTequioxx-820x340

Most people, at one point or another, have owned a horse that needed to be on a nonsteroidal anti-inflammatory drug (NSAID) for pain relief from an injury or arthritis.  There is along list of products to pick from when discussing a pain relief medication plan with your veterinarian.  An effective, and one of the most commonly used NSAIDs is Phenylbutazone (Bute).  However, Bute has a history of causing gastric ulcers in some horses that are on it for an extended period of time.  This side effect has driven veterinarians and clients to consider the use of alternative NSAID options.  Another good NSAID that is labeled for use in horses and is safe for long term use is Equioxx.  Equioxx is a product that is used in clinics as an intravenous medication, but can be sent home with clients as a paste resembling a deworming tube.  However, this product is unpopular with clients due to its cost, and after daily doses, can become a battle to administer to horses.  This is why a dog product, Previcox, has joined the list of NSAID options.


Extra-label drug use

For clients that are familiar with Previcox, they will know that there is a dog pictured on the bottle.  Previcox is labeled for canine use, so how can it be used for horses?  Extra-label drug use (off-label drug use) is the use of medications intended for other species.  Veterinarians prescribe medications for extra-label use for specific conditions, such as:

  1. There is a valid Veterinarian-Client-Patient relationship
  2.  The animal may suffer or die if not treated, and there is no approved animal drug with the appropriate active ingredients, dosage form, concentration, and effectiveness
  3. The animal drug is only compounded with an approved animal or human drug
  4. The drug is not on the list of drugs prohibited from extra-label use

So how does this apply to Preicox?

Equioxx vs. Previcox

Equioxx and Previcox are both firocoxib, a NSAID used to control inflammation and pain that are created by the same manufacturer, Merial.  Firocoxib is a NSAID that has “proven to control joint pain and inflammation associated with equine osteoarthritis or degenerative joint disease (”  However, Previcox is a pill that is labeled for canine use, whereas Equioxx has, up until now, been in a paste or IV form that is labeled for equine use.   Veterinarians have found that Previcox was effective in horses and allowed clients an easy form to administer to horses while also being less expensive compared to its sister drug Equioxx.  The difference in cost from the tablet Previcox and the paste Equioxx probably has something to do with the cost to manufacture the product in a paste form compared to a tablet.

The Veterinary Dilemma

While it is important that veterinarians provide the best treatment with effective and cost-effective options for their clients, there has been a gray area when it comes to proscribing Previcox for the use in horses.  The extra-label use of a drug like Previcox where there is an equivalent product on the market (Equioxx) that is labeled for equine use, but is just not as cheap, does not warrant approval for prescribing under the extra-label law listed above.  Previcox is prescribed for horses whose owners “struggle to get a paste into them.”  While veterinarians want to prescribe cost effective options for their clients, there are risks to the veterinarian for prescribing drugs off-label.

Equioxx Tablets

This ongoing issue of having a drug like Previcox available, but not labeled for use in horses is something that Merial (the creator) has known about and has been working to address.  Solving this issues takes time, even though it is simply a change in dosage form.  The tablet form of Equioxx still needs to go through all the same channels as a new drug to prove that it is safe and effective, and happily that time has come.  Equioxx tablets are scheduled to be available to veterinarians starting the first week of October 2016.  This product is scheduled to be the same cost as its sister drug Previcox.  Finally, this drug will allow veterinarians to safely prescribe this effective drug in the easy to give tablet form, without the conflict of proscribing a drug off-label.

For clients who use Equioxx/Previcox prior to this, should be aware that the tablet is dosed for a 1000 pound horse.  Though the drug has a safety region that allows clients to comfortably give a tablet to the horse that is not exactly a 1000 pounds there are things to keep in mind.  Make sure you read your governing bodies rules regarding NSAID use before a show. Some will allow you to give one NSAID, up to 12 hours, prior to a show.  Horses that weigh less than a 1000 pounds and as give these tablets in that time frame may not clear the drug fully to prevent testing positive in a drug test.  In these cases, it is safer to give a horse the paste form where the dial can be accurately dosed for the horse’s weight, so that it clears the system in the required time prior to a show.

If Equioxx tablets are something that you would like to consider for your horse, please talk with your veterinarian to see if it is a good option for your horse.


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