Veterinarians might want to split tablets for many reasons. Even with all the veterinary-only medications on the market, some treatment plans rely on human drugs available only in strengths unsuitable for pets. While specialty compounded products are an option, an appropriate lower dose is often achieved by splitting a commercially available medication. But is splitting allowed, and will doing it guarantee that the divided dose is precisely half of the original strength?
Another reason veterinarians consider tablet-splitting is stocking issues. Sometimes, a hospital might have only a high dose of certain medications. At other times, the doctor might try to save the pet owner money if the cost is less when a higher-dosage tablet is dispensed and split.
Practitioners should also consider these questions:
- Is it appropriate to dispense split tablets in the clinic, or must the client do the work?
- Do the prescriptions need to be handled by a pharmacist?
- Is a scored tablet safe to split?
- What additional steps must you consider before putting pen to paper or pills in a bottle?
Pharmaceutical Considerations
Besides determining the dosage and length of therapy, a veterinarian must consider other factors when deciding whether a split tablet is the best treatment plan. One is knowing whether the divided tablet will deliver the prescribed dose. Multiple studies have shown that objective was not always achieved, leading the U.S. Food and Drug Administration in 2013 to require drug manufacturers to prove which tablets are appropriately made to allow for splitting, with equal amounts of the active ingredient in each section.
A scored tablet might not always be FDA-approved for splitting. However, the notch is usually a good indication.
Regulatory Considerations
Another factor is whether splitting alters the finished dose, unlike transferring medication to another package or container. Technically, the process is compounding. The FDA has not officially clarified whether splitting is compounding, and state regulations vary. Still, a veterinarian might technically compound a drug without assurance of the correct dosage.
Therefore, a best practice is to advise pet owners to split one tablet at a time and use the remaining portion as the next dose before repeating the process. This habit ensures that the combined dose is consumed before another tablet is split, perhaps unevenly. Veterinarians can avoid violating compounding regulations and maintain best practices by having the pet owner split dispensed medications.
As for the actual splitting, keep this in mind:
- Oddly shaped or small tablets might not fit nicely into a pill cutter.
- Tablets should not be split more than once unless they are scored into thirds or quarters.
- Capsules should never be opened and the powder divided. In this situation, an oral compounded medication from a specialty pharmacy might be a better option to ensure the client administers the correct dosage.
Counseling Considerations
Prescribing, dispensing and medication errors seem to increase with pill-splitting due to mistakes by the clinic, pharmacy or, most often, pet owner. The problem usually happens when the veterinarian or pharmacy splits the drug, and then the client misunderstands the directions and thinks the medication must be split again. In that case, the pet gets a fraction of the needed dose or too many split tablets.
Veterinarians can avoid dosing errors by counseling clients on how to use a pill splitter, one tablet at a time, and to give the remaining portion at the next dose. The directions should be printed on the product label and written on discharge instructions, along with explaining the original strength of the medication and the ending dose once the tablet is split.
When Splitting Is Appropriate
No specific list indicates which drugs are FDA-approved for splitting. Still, the information is in the “How Supplied” section of the professional label insert with human drugs and some veterinary drugs. To look up a specific drug, consult the drugs.com database.
Note that just because a brand-name drug is approved for splitting does not mean the generic version is OK, too. Generic drug makers must obtain individual product approvals based on the manufacturing processes.
The bottom line is this: Always check a drug’s package insert to determine its FDA status for splitting. This step is critical when:
- You prescribe a narrow therapeutic index drug, and an excessive dose could cause dangerous side effects.
- You treat an acute disease, and an incomplete dose could lead to a lack of efficacy and potentially a treatment failure.
When Not to Split
Since many drugs, especially veterinary-only products, are not FDA-approved for splitting, the next consideration is making sure the medication shouldn’t be crushed, split or manipulated. Always check the package insert for a “Do not crush” alert. These drugs often have extended-release or slow-release properties that splitting could harm and potentially release dangerously high or low doses of active ingredients at one time. They might include sublingual drugs, hazardous drugs, drugs with an enteric coating to protect the gastric or mucosal lining, and drugs with an especially bitter taste. In those situations, working with a compounding pharmacy is the best solution.
Even with all the available drugs, achieving the correct dose for veterinary patients can be a challenge. Choosing an FDA-approved medication is always the safest option, but it might not be the best for a particular patient or treatment plan.
ASK YOURSELF
Here are vital questions to consider when prescribing split tablets:
- Is the pet owner capable of splitting the tablet into the appropriate size?
- Is the splitting protocol easy for the owner to understand?
- Would a narrow therapeutic index drug work better as a compounded medication?
- Is the drug FDA-approved for splitting?
- Is the drug listed as not to be crushed, split or manipulated?
- Is another FDA-approved medication available that wouldn’t require splitting?
WHAT THE STUDIES SHOW
- Lack of Medication Dose Uniformity in Commonly Split Tablets, bit.ly/3UUDSJ1
- Analysis of Drug Content and Weight Uniformity for Half-Tablets of 6 Commonly Split Medications, bit.ly/3QYO1mu