Understanding the Veterinary Patient

It is a typical day in the pharmacy: you are taking care of business, and a patient brings in a prescription for their dog. The local veterinarian has prescribed lorazepam 6 mg, once daily. As a pharmacist or pharmacy technician, your clinical skills kick in, and your first thought is: “This dose is going to kill this dog.” As a result, you call the vet, and have a conversation only to find out that because of the way dogs digest and metabolize medication, that this is, in fact, the correct dosage.

Currently pharmacists and pharmacy technicians have little to no formal education regarding our veterinary patients, although our responsibility to them is the same as our human patients. We are seeing more pet prescriptions in day-to-day practice than we ever have in the past, and we need to be knowledgeable about how to dispense and counsel the pet owner. This challenge has become so evident that the pharmacy industry has begun making recommendations for pharmacy staff education.

The American Pharmacists Association is encouraging pharmacists and pharmacy technicians to become more knowledgeable about veterinary drugs and their usage. The National Association of Boards of Pharmacy has a resolution that states pharmacists possess competence and have resources necessary to appropriately dispense and provide care to veterinary patients. They have also created a model state pharmacy act and rules. A report by the American Association of Colleges of Pharmacy states that pharmacists in all practice settings need the knowledge and skills necessary to treat animal patients. What, then, does the pharmacist and pharmacy technician need to know to effectively deal with veterinary patients?

First, we need to know a little about the veterinarian. Veterinarians treat a wide variety of patients, not just the cats and dogs we normally consider. If they are in a small animal and exotic practice, they may be treating ferrets, birds, lizards, hamsters or any number of other small pets. In a large animal practice, they could be seeing livestock, chickens, horses, or even bees. Veterinarians specialize just the same as human doctors. Therefore, specialties exist in ophthalmology, emergency medicine, surgery, dermatology and many more.

We also need to be aware that not all veterinarians have Drug Enforcement Administration (DEA) numbers because not all vets prescribe controlled substances. Veterinarian practices are also somewhat different from human doctors. They see patients, the animal, and they have clients, the animal’s owner. Many of them not only prescribe, but they dispense from the office. In fact, roughly half of the veterinary office revenue comes from the medications they dispense, food and other items that they sell.

Next, we need to spend some time on the patient, starting with dogs. Giving a dose of medication to a dog can be difficult. Dogs are also gorgers when it comes to eating. This can cause problems with toxicity if too much of something is ingested. They have a horizontal digestive tract, so there is no benefit of gravity to move medication through the tract, and the digestive cycle is rather short compared to humans. For this reason, sustained release medications may not be effective, or may be dosed higher than we would expect. These meds don’t have enough time to completely release and be absorbed before they are excreted. There is also one component of medications that is extremely toxic to dogs. A dog should never be given anything containing Xylitol. This product is rapidly absorbed, creating an insulin response and hypoglycemia. This happens so rapidly that it usually ends up being fatal. Many commercially prepared liquid medications contain Xylitol, as well as many natural peanut butters. Pharmacists and pharmacy technicians should always check before dispensing to make sure what is given is Xylitol free.

Naturally, we have cats next. Cats are meticulous groomers, which can be used as a way to medicate them. Also like dogs, they have a horizontal digestive system, so again, gravity plays no role in moving medication through the tract. They also have a Jacobson organ, which pairs their sense of smell with their sense of taste. As a result, if the smell of a medication offends a cat, getting them to take it will be very tough. Pharmacists need to find smells that cats like or find interesting to use in medication. The major toxicity in cats is acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDS). These require conjugation by glucuronide to prevent toxic metabolites from forming. In cats, this pathway becomes saturated almost immediately allowing other pathways to take over, thus allowing toxic metabolites to form, and ultimately causing renal damage. Again, this usually ends up being fatal to the animal.

Compounding Considerations

Compounding for animals becomes a unique challenge as smell and flavor are more important to an animal above all other considerations. If the medication smells bad, or has an off-putting flavor, the animal is likely to reject the medication. It should be noted, unlike humans, color is not as important of a consideration in many instances since dogs cannot see color and cats have a limited color spectrum. Therefore, a medication flavored like fish and colored gray will look off putting to a human, but to cat it will smell and subsequently taste like food.

When compounding prescriptions for animals the final product should be labelled, “Not for use in food producing animals.” The prescription must also be documented as to the reason for compounding. This would include notes such as, “must be xylitol free,” or “must be alcohol free,” and “dosing not available commercially.”

What many pharmacists and pharmacy technicians are not aware of is that the use of human drugs on animals is considered to be extra-label use as defined 21 CFR Part 510. Under these regulations, all drugs labelled for human use and given to an animal can only be done under the specific orders of a licensed veterinarian. There are a number of horror stories from a study done in Oregon where pharmacists received orders for a prescription medication that the pet would tolerate, only to be given an alternative medication over-the-counter that ended up poisoning the animal. It should be noted that unless you consult a veterinarian, you are not legally authorized to make these substitutions and can be held legally accountable if you fail to consult a veterinarian first.

Regular scope of practice also applies to veterinary prescriptions in the same manner as human prescriptions. This means a family doctor cannot prescribe medication for their pet. If you flip the equation, though, a veterinarian can prescribe medication to a human in a case where a zoonotic disease is detected in a pet, and it is recommended that the humans in the household undergo treatment or prophylaxis as well. The protocols are usually well documented for the veterinarian to prescribe these medications, often with instructions for follow-up with the family physician at a later date.

Lastly, your duties as pharmacists and pharmacy technicians under the Michigan Public Health Code apply to veterinary prescriptions as well as human prescriptions. This means you must be able to accurately and safely interpret the prescription, select an appropriate drug product, provide adequate storage and compounding of that product, and be able to consult the patient on use, side effects and accurate dosing of the prescription. The Board of Pharmacy and a court of law could hold you accountable for negligence if any of these requirements are not met.

A prescription must be documented for the animal’s name, as well as the owner’s name. The veterinarian will not have an NPI number, but if the prescription is for a controlled substance, a DEA registration number is still required. When submitting the controlled substance to MAPS, the owner’s ID and information should be sent to MAPS.

While processing prescriptions for animals poses special challenges based on our education, the business case for processing these prescriptions is important. These prescriptions are cash-paying patients in an environment where our profession faces declining reimbursement from insurance companies. Learning to process these prescriptions safely can provide a necessary infusion of profitable business.

By Thomas A. Magnifico, R.Ph., FACA, FACVP, veterinary compounding specialist, Keystone Pharmacy and Adam M. King, C.Ph.T., PRS, billing, technology and regulatory specialist, Keystone Pharmacy and adjunct instructor of health sciences, Baker College of Muskegon.