Medication Acronyms Lack Standardization

Over the past 3 decades, an interesting development has been made in the naming of medications. After a medication has been on the market for a few years, a new "extended" version of it is suddenly available. Quite often, this new version just happens to appear on the market only a few months prior to the original version of the medication losing its preferred patent status.

As pharmacists, we are often excited and delighted to see an extended version of a medication become available. We all know that medication adherence is an issue, so the prospect of offering a patient a once- or twice-daily dose of a medication, rather than a drug that they need to take 3 or 4 times a day, is a great step towards compliance.

We could discuss the point that drug manufacturers are simply attempting to maintain their market share by extending their patent volume with this new formulation; however, that would be quite cynical of this pharmacist and perhaps better suited for a different article.

However, an issue that I would like to address is the lack of standardization in the process of naming these extended-version medications. Sometimes, it appears that an acronym is placed after the name of a drug at the manufacturer's whim, with little or no explanation of what it means.

An acronym may be added to the end of the medication's name to an attempt to describe that it is some sort of longer acting or super version of the original medication. Examples of this include:

• CD (controlled delivery)
• TR (time release)
• LA (long acting)
• ER (extended release)
• XT (extra time)
• SR (sustained release)
• XL (extra long, extra large)
• SA (sustained action)
• CR (controlled release)
• DR (delayed release)
• EC (enteric coated)
• HS (bed time dosing)
• PM (bed time dosing)
• CC (continuous control, constant control)
• XR (extra release)

As you can see, a number of acronyms are used with little or no definition of their exact meaning related to the medication name they are attached to. The acronym is just an extension of the original product name, thus creating a new trade name for the product.

To further confuse the situation, some medications not only have the original release version, but they also have 2 completely different extended versions with completely different acronyms.

One particular seizure medication has an EC version with twice-daily dosing, but there is also an ER version with once-daily dosing. Another antidepressant medication has not only an SR version with twice-daily dosing, but also an XL version with once-daily dosing.

When interpreting and filling prescriptions, pharmacists need to be vigilant in their review and determination of the appropriately selected product as it relates to the medication's acronym. It is possible that the trade name for a product may contain the acronym SR while its AB-rated generic equivalent may include the acronym XR or ER in its name.

The pharmacist must not only evaluate the patient to assure that the medication is appropriate for the specific situation, but also assure that the acronym designation is appropriate for the dosing regimen prescribed by the physician.