What your pharmacist should know about your pet’s medication, excerpt from full article published in Pharmacy Times.
It is a typical day in the pharmacy and your patient brings in a prescription for their dog. Their local veterinarian has prescribed Lorazepam 6mg, once daily. As a pharmacist your first thought is: “This dose is going to kill this dog.” As a result, you call the vet only to find out that because of the way dogs digest and metabolize medication, this is the correct dosage.
Currently pharmacists have little to no formal education regarding your veterinary patient, although their responsibility to them is the same as to human patients, including being knowledgeable about how to dispense and counsel the pet owner. What, then, does the pharmacist need to know to effectively deal with veterinary patients?
Let’s start with your dog. 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 their medications. The major toxicity in cats is Acetaminophen and 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 medications 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 a cat it will smell and taste like food. Not all pharmacies will compound a medication if that is what your veterinarian has prescribed. Few pharmacies and pharmacists are trained in compounding and have the resources to “make” your prescription. Look for nationally accredited (PCAB) compounding pharmacies or have your veterinarian send your Rx to Keystone Pharmacy (www.keystonerx.com).