Compounding Concerns for Animals Near and Dear

A article by Alice Villalobos, DVM that appears in the Veterinary Practice News, which can read here, makes some very good points about compounding for animals.

First, Villalobos asks:

Competitive pricing, counterfeit drugs, unreliable sources for drugs and the honesty that our profession must maintain present an everyday dilemma. How can veterinarians avoid being tarnished by scandals of adulterated and contaminated food and drugs and still maintain the public’s trust?

Next, Villalobos points out a number of the current issues regarding compounding for animals:

The hundreds of compounding pharmacies nationwide do not use standardized methods or bases for their compounded products. Only a few pharmacies run tests on the stability of their purchased and outsourced compounds.

Some are illegally manufacturing medications under the guise of pharmacy compounding. The field has sprawled into a confusing crossover situation for veterinarians. We have human pharmacists preparing products for animals. If they do not respect and understand the human-animal bond, they might purchase “bargain” bulk or raw chemical preparations made in China and other unreliable sources to save money. Without testing these bargain agents for reliability, stability and contaminants, our patients are at risk.

For instance, potassium bromide, cisapride and diethylstilbestrol and other discontinued or no-longer-approved human drugs can be prepared only from bulk chemicals for veterinary medicine, and they are loosely supervised. We need to protect our veterinary patients from being victimized by this potential hazard. 

Proper Handling

For example, Pergolide for horses is available only through compounding pharmacies. Compounded Pergolide is stable for 30 days and must be kept in a temperature-sensitive environment. Many pharmacies sell Pergolide with a six-month dating, and the product is not stored adequately to ensure its stability.

Finally, Villalobos makes an excellent point, with quotes from Gigi Davidson, RPh, Dipl. ICVP, director of clinical pharmacy services at North Carolina State University, about the Veterinarian ultimately being responsible:

 “Ultimately, the veterinarian is accountable for what happens to the patient.""Veterinarians must realize that even if evidence abounds regarding the safety and efficacy of a compound, they are responsible for determining whether the compound is achieving the desired therapeutic effect,” Dr. Davidson wrote in a recent article for AAHA News.

“Veterinarians should keep track of the results for their patients who have been prescribed compounds and make sure they know what exactly is going into each prescription.” 

Davidson cited the case of a canine patient treated with pyridostigmine (Mestinon) solution for myasthenia gravis at the N.C. State College of Veterinary Medicine's teaching hospital. The dog was doing well on the treatment but returned several months later weak and unable to stand.

"Apparently the owner had taken her prescription for pyridostigmine solution to a compounding pharmacy and the well-intentioned pharmacist had offered to compound a more dog-friendly flavor of the pyridostigmine," Davidson said. "Unfortunately, the pharmacist included methylcellulose in the vehicle which completely bound the pyridostigmine, making it unavailable for absorption. Luckily, we realized the mistake before the dog was euthanized."