FDA ALERT: Regumate, Matrix (altrenogest ORAL products) pose human health risk

Mare Foal BET Pharmacy

FDA ALERT: Regumate, Matrix (altrenogest ORAL products) pose human health risk

As a compounding pharmacist and part time blogger, I’m subscribed to just about all of the FDA alerts related to drugs. The other day I received this email and it took me by surprise a little just because it mentions altrenogest, something I too compound with. As I read on though, none of the notification came as much of a shock. It relays the message that exposure to progestins (a form of progesterone, in this case: altrenogest is a synthetic progestin only approved for animal use – not human). The original FDA communication I received is below, including links to the FDA Alert.

Any female or male exposed to progestins can have adverse effects from that exposure. However, let’s keep in mind that more specifically, as the FDA notes here, is that this can especially be a problematic in teenage girls (their reproductive system). When you stop to think about it, Altrenogest is no different necessarily than any progestin-only birth control on the market, but remember this is for a HORSE (much larger than your average female teenager).

Many of these FDA approved products are made specifically to be readily and quickly absorbed through mucous membranes; skin exposure can mean a major disruption to a human female’s reproductive system. If proper precautions aren’t taken (i.e. wearing chemical resistant gloves, face shield and apron) this could mean detrimental health effects for anyone exposed. Whether administering to the horse directly, in their feed or even cleaning a stall that had Regumate sprayed on the feed; you must properly protect yourself or employees from exposure.

BETs two Altrenogest formulations: Altrenogest 150 mg/mL and Altrenogest 500 mg Microparticle are INJECTABLE forms of Altrenogest. Each are unique in their delivery system because of their long acting formulation (links to published research of these formulations below). Altrenogest 150 mg/mL is typically administered once every 2 weeks and our Microparticle formulation is given just ONCE a MONTH. Aside from the convenience, if theres a cost involved for administering the oral products daily this would also certainly cut labor costs as well.

Veterinarians typically use the Altrenogest 150 mg/mL as a progestin supplement for pregnancy maintenance while the Microparticle formulation is given once a month for estrus suppression. Aside from the cost difference, the once a month formulation (which is more expensive) also has a very low incidence of injection site reactions; which makes it ideal for use in horses DURING the race/show season.

In terms of safety, BOTH of our injectable formulations present the user with a much lower risk of exposure given the use of syringes and needles to administer the dose. There’s virtually no clean up (properly dispose of sharps in biohazardous waste) after it’s administered and a lower risk of our formulation being sprayed or splashed onto the human giving the injection.

Check out this PDF from Auburn on how to properly give an injection in a horse.


FDA communication Received July 3, 2018:

FDA Animal Drug Safety Communication: FDA highlights potential health risks to people exposed to altrenogest products for horses or pigs

The U.S. Food and Drug Administration is alerting veterinary medical professionals, as well as those who work with horses and pigs, that a synthetic progesterone product commonly used in these animals may cause reproductive system disorders and other adverse effects in people who become exposed to the drug. The FDA is providing this alert because of the nature of the adverse events, some of which have occurred in teenage girls.

Altrenogest belongs to the class of drugs called progestins and is used to suppress estrus (commonly called “heat” or “season”) in mares (female horses), and to synchronize estrus in gilts (young female pigs). It is marketed under several brand names, including the equine products Regumate, Ovamed and Altren; and the swine products Matrix, Chronomate and Swinemate. The equine products are available via a veterinarian’s prescription and can be administered directly on the base of the mare’s tongue or on the mare’s feed. The swine products are available over-the-counter and are administered on a portion of the gilt’s feed. These liquid products may be administered to the animals on a daily basis for prolonged periods of time.

The agency has received 130 reports of accidental human exposure to altrenogest products between October 6, 1987 and May 30, 2018; 121 of those were for Regumate, approved in 1983, and nine reports were for Matrix, approved in 2003. Although the FDA has not received any reports for the other (generic) products, the agency’s alert includes these products because they are used in the same manner as Regumate and Matrix and on the same animal populations, and therefore have the same risk for adverse events.

Read entire article.

More Animal Health Topics


*Check out our published research:

Evaluation of Sustained Release Progestin Formulations in Mares
P. J. Burns D. L. Thompson, Jr, W. A. Storer, R.M. Gilley 

Evaluation of Altrenogest LA 150 For Maintenance of Pregnancy in Mares
C.M. Morrow, D.V.M and P.J. Burns, Ph.D. 

Use of a Compounded Proprietary Long-Acting Progesterone Formulation for Maintenance of Pregnancy in Mares
D.K. Vanderwall, J.L. Williams and G.L. Woods 

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