What is the different between an IR and ER medication?

There are a lot of medications that come in different forms that are known as immediate release (commonly written as IR) or extended release (commonly written as ER or XR). You might see the symbols XR, ER or sometimes IR after the name of your medication. When you see these letters, it is telling you how fast the medication is going to work inside the body. When it comes to IR drugs, it is what the name suggests, they are made to work fast after you take the medication. Most of the time, these drugs will not have the “IR” at the end of their name, as most drugs are made this way. So, think of metformin for high blood sugar. This is the fast form of the drug. What you will see most commonly is ER or XR at the end of a drug name. An example of this is metformin ER. This tells you that your medication is going to start working a little slower than your fast release medication. It also means it will stay in your body for a longer time. The main difference you will see with these 2 different types is how many times you are taking it in the day. Metformin can be taken 2 to 3 times a day compared to metformin ER once a day. The medications still work just as well whether you are taking the IR or ER versions.