What does xr stand for in medications

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:. 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.

In some cases the drug is encased in a coating that dissolves after a period of time to deliver the active ingredient. Different thicknesses of this coating enable the drug to be released in a staggered effect. In a diffusion system, the drug is released over time through a matrix of small openings in an outer membrane. As mentioned above, the mechanism used to disperse the drug can vary and this can affect how the drug acts on the body.

Dosing instructions may differ; for example, Wellbutrin SR is taken twice a day while Wellbutrin XL is taken once a day. Also, some of these pills should not be crushed, chewed or divided while others can be safely divided but not crushed or chewed. When switching between different brands of the same drug, always check with your healthcare provider to find out if there are any differences you should be aware of.

Some medical conditions, such as hypertension and diabetes, can be controlled much more effectively with extended-release medication because a more consistent level of the drug is maintained in the bloodstream. In turn, this can reduce adverse reactions since the body isn't subjected to the sudden effect of medication hitting the bloodstream all at once.

Because extended-release drugs are taken just once or twice a day, it's easier for patients to follow the dosing regimen and gain the most therapeutic benefit from the treatment. Note: Delayed-release products do not fall into the same category as extended-release. Delayed-release are designed to release the drug into the body hours after the drug has been ingested.

Between the time of ingestion and the time the drug is released, no absorption of the drug takes place.