The Little-Known Pharmaceutical Wizardry That Benefits Pets

Analysis by Dr. Karen Shaw Becker

compounded medications for pets

Story at-a-glance -

  • Compounded medications give veterinarians the flexibility to customize drugs and natural remedies to the individual needs of their patients
  • Examples of compounding for veterinary use include creating oral suspensions from crushed tablets, or adding flavoring to a commercially available drug to make it more palatable
  • There are many benefits of compounding, including creating nonstandard dosages for patients who don’t respond well to standard drug dosages
  • Pharmacists don’t typically receive training in veterinary pharmacotherapy, including compounding, so it’s important that veterinarians work with pharmacists who’ve received specialized training or credentials in veterinary compounding

If you've never heard of drug compounding for pets or veterinary compounding pharmacies, you're hardly alone.

Many conventional veterinarians aren't in the habit of prescribing compounded medications, and for that matter, neither are many physicians. This is unfortunate, because compounding gives practitioners the flexibility to customize drugs for individual patients, which is often much more effective than the traditional one-size-fits-all prescribing approach.

What Is Drug Compounding and Why Is It Necessary?

From the American Pharmacists Association (APhA):

"Compounding is the creation of a pharmaceutical preparation — a drug — by a licensed pharmacist to meet the unique needs of an individual patient (either human or animal) when a commercially available drug does not meet those needs.

A patient may not be able to tolerate the commercially available drug, the exact preparation needed may not be commercially available, or a patient may require a drug that is currently in shortage or discontinued.

The U.S. Pharmacopeia Convention (USP) formally defines compounding as 'the preparation, mixing, assembling, altering, packaging, and labeling of a drug, drug-delivery device, or device in accordance with a licensed practitioner's prescription, medication order, or initiative based on the practitioner/patient/ pharmacist/compounder relationship in the course of professional practice.'"1

Compounding pharmacies can put drugs into specially flavored liquids, topical creams, transdermal ointments and gels, suppositories, or other dosage forms to meet a patient's unique needs.

A compounded medication is a customized form of an FDA-approved human or animal drug. These drugs are created on a case-by-case basis for a specific patient — they are not created in bulk. The FDA considers compounded medications to be "extra-label drugs."

Veterinary compounding must be done either by a veterinarian or a compounding pharmacist who has received a prescription from the veterinarian. Examples of compounding for veterinary use can include:2

  • Mixing two injectable drugs in the same syringe so the pet only has to receive one shot
  • Creating an oral suspension from crushed tablets for pets who are difficult to pill
  • Adding flavoring to a commercially available drug to make it more palatable
  • Creating a transdermal gel for a drug typically taken through other routes, for example, methimazole ointment to place inside a hyperthyroid cat's ear
  • Mixing two solutions for instilling into the ear to make administration less stressful for the pet

Benefits of Compounding

Many patients (human and veterinary) don't respond well to standard drug dosages, while others experience adverse side effects. Compounding pharmacists can create nonstandard dosages for those patients; they can also compound necessary medications into more effective or easier-to-administer forms, such as those noted above (transdermal gels, topical sprays, suppositories, lozenges).

Compounding pharmacies can also combine compatible drugs into a single dosage form (e.g., a topical cream) to simplify medication schedules.

When standard medications are out of stock or temporarily unavailable, compounding pharmacies can usually obtain the drugs in bulk powder form and compound a similar preparation.

Compounding pharmacists can flavor medications to please any palate (human or animal) and even eliminate the aftertaste.

Nonactive ingredients (excipients) in medications can cause allergic or other adverse reactions in some patients. Compounding pharmacies can formulate medications to remove such unnecessary ingredients as dyes, sugar, gluten, lactose, alcohol, and preservatives.

Veterinarians and MDs who understand the benefits of compounded pharmaceuticals often create unique formulations to meet the specific needs of their patients, and compounding pharmacists are able to prepare these customized formulas.

I rely on compounding pharmacies on a daily basis for many of my patients. For instance, heartworm pills often come in three broad dosages for small, medium and large dogs. The same pill is prescribed for all pets up to 25 pounds, which means the 4-pound dog gets the same dose as the 24-pound dog.

Dogs at the lower end of the weight range received a whole lot more drug per-pound, which can be a problem if the animal suffers from seizures, liver shunts, poor metabolism or gastrointestinal (GI) disease. Often times we can avoid unwanted side effects by having the exact amount of medication needed for their specific body weight compounded for them.

Some pharmacies, like Pet Health Pharmacy, compound natural remedies for integrative veterinarians, and can offer customized delivery systems (powders, capsules, flavored liquids or transdermal gels) for animals who need hypoallergenic or flavor-free alternatives.

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Regulation of Compounded Drugs

From the American Veterinary Medical Association (AVMA):3

Compounding is regulated by both the federal government (FDA) and state governments. The FDA regulates compounding for animal patients as a subpart of its Extralabel Drug Use (ELDU) Rules.

FDA also has a Compliance Policy Guide (CPG) which describes more about how it regulates compounding for animals and what activities it defers to the state. The FDA generally defers day-to-day regulation of compounding by veterinarians and pharmacists to state authorities.

In November 2019, the FDA issued new draft guidance for animal drug compounding that will replace an insufficient 2015 draft guidance that was withdrawn in 2017.4 The new draft guidance is under review by the AVMA, its membership, and state veterinary medical associations.5

The state boards of pharmacy oversee pharmacy practices within the states, while the state veterinary medical boards oversee the practice of veterinary medicine, including prescribing.

Before using a pharmacy, veterinarians should also consider whether the pharmacy is compliant with the U.S. Pharmacopeial Convention (USP) standards, such as General Chapters <795> and <797> for non-sterile and sterile compounding for both humans and animals.

Do Pharmacists Receive Training in Veterinary Compounding?

According to the AVMA, many pharmacy schools don't train in any type of veterinary pharmacotherapy (including compounding). Veterinary-specific pharmacy training (including compounding) is typically obtained by pharmacists through independent continuing education.

Since drugs and compounds often behave very differently in animals than in people, veterinarians should confirm that any compounding pharmacists they work with have specialized training or credentials in veterinary compounding.

In addition to information on active ingredient(s), veterinarians should advise pharmacists of any restrictions on inactive ingredients for the compounded preparation, such as no xylitol in medications prescribed for dogs.

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