Highlights From the Video

Immediate release the medication is released immediately and results is quick onset and a peak blood level. This type of formulation is generally less expensive and may be advantageous in some cases. For example, if you are using quetiapine at night in part for its sedating effects, I will use immediate release because I want a rapid effect. The same with methylphenidate or bupropion. 

The problem is this formulation requires twice a day or even three times per day dosing and results in more peaks and troughs. In general, for medications that are being used for maintenance you want consistent blood levels and not peaks and troughs.

With IR formulations, there can be more side effects and addictive potential. We believe it’s the rapid rise in blood levels of the medication that cause side effects and with medications like amphetamines for ADHD it’s the rapid rise in medication levels that can result in euphoria and thus addictive potential.

Extended release does not change the active ingredient in the medication, rather it provides a different delivery mechanism that slows the release of medication over an extended period of time. This has the opposite effect on blood levels when compared to IR. There will be less peaks and troughs and more sustained blood levels of medication. The advantage is once daily dosing and potentially fewer side effects for the pervious mentioned reasons. 

The downside is these medications tend to cost more money and some have argued when initiating these medications, a patient who has an adverse reaction will have symptoms longer with XR. Although clinically I’m not sure this is true and will generally use extended release if possible for maintenance medications.