One person takes metformin for their diabetes; another person takes glimepiride and sitagliptin. What’s the difference? Does one pill work better than another? The answer depends on how each medication works and which medicine your doctor believes will work best for you.
What problems do the pills help?
Let’s start with how the medicines help to manage blood glucose levels. High blood glucose levels are usually the result of not enough insulin in the blood stream or of insulin that isn’t working well. To review, insulin’s job is to help move the glucose in the blood into all the millions of cells in your body. In addition, the liver stores extra glucose and releases it as needed to prevent low blood glucose. In type 2 diabetes, sometimes the liver releases extra glucose that contributes to blood glucose levels that are higher than normal.
- Not enough insulin: If a person with diabetes eats a large meal with lots of carbohydrates, and the cells in the pancreas can’t make enough insulin to process the resulting glucose, then blood glucose levels stay high.
- Insulin that doesn’t work well: If a person with diabetes is overweight and inactive, his or her insulin has a hard time doing its job, a condition that’s often called “insulin resistance.�?
- Too much glucose released from the liver: This process is beneficial when it helps prevent low blood glucose levels after a person goes a long time without eating (like overnight when sleeping). This same process, however, can sometimes contribute to elevated glucose levels in people with diabetes.
How do the common pills for diabetes work?
The different medicines attack different problems and there are often several medicines in each category.
- Biguanides (metformin): This medicine does two things. It makes the muscle cells more sensitive to insulin so that the insulin works better, and it also keeps the liver from releasing too much glucose.
- Sulfonylureas (glipizide, glyburide, glimepiride, nateglinide, repaglinide):This class of medicines stimulates the pancreas to make more insulin.
- Thiazolidinediones (pioglitizone): This medicine makes muscle cells more sensitive to insulin so that the insulin is able to work better.
- Alpha-glucosidase inhibitors (acarbose, miglitol): This class of medicines slows down the digestion of carbohydrates so that blood glucose levels don’t rise as high after meals.
- DPP-IV inhibitors (sitagliptin, saxagliptin, linagliptin): This class prevents the breakdown of a beneficial hormone (GLP-1) that does three things: it stimulates the pancreas to make more insulin, slows gastric emptying, and keeps the liver from releasing too much glucose.
Doctors choose a particular medicine for you depending on whether the goal is to increase insulin production or reduce insulin resistance. Sometimes they recommend a combination of medications, including a class of medications called incretin mimetics, as well as the various types of insulin. Look for information about these medications in upcoming blogs.