6 classes of diabetes drugs and how they work

Diabetes drugs can save your life—but they come with side-effects—and there are many to choose from. Be informed, know your options, and make the best choice for you.

• One of the things you need to know if you have diabetes is what kind of meds are available. Well, as it turns out, there are many. In fact, the list of medications for type 2 diabetes is surprisingly long and confusing.
• There are six categories and within each are several choices. And often, each specific medicine has different forms.
• Manufacturers also use different names for essentially the same medicine. We won't tell you about all the drugs—that's for your doctor and pharmacist to understand and explain—and some medications aren't allowed in all markets. But here is an overview of the six main classes:

Sulfonylureas stimulates the beta cells in your pancreas to release more insulin. These drugs have been in use since the 1950s and have gone through a few generations of change. They are typically taken one to two times a day, before meals. All have similar effects on blood glucose levels, but they differ in side effects, how often they're taken and their interactions with other drugs.

Meglitinides also stimulate the beta cells to release insulin. They're usually taken before meals, three times a day. A benefit of sulfonylureas and meglitinides is that they both work quickly. The downsides? Both can stimulate weight gain. And since they stimulate the release of insulin, in rare cases they can cause hypoglycemia. Some also interact badly with alcohol.

Biguanides lower blood glucose levels primarily by decreasing the amount of glucose produced by the liver. In this category is metformin, one of the most popular pills in the world for diabetes. One reason why it's so popular: metformin also helps make muscle tissue more sensitive to insulin so glucose can be absorbed. It's usually taken two times a day. A side effect of metformin is diarrhea.

Thiazolidinediones are drugs that help insulin work better in the muscle and fat, and also reduce glucose production in the liver. The first drug in this group, troglitazone, was removed from the market because it caused serious liver problems in a small number of people. Other medicines in this category haven't shown the same problems, but doctors still monitor their patients' liver health as a precaution when taking this class of medication.

Alpha-glucosidase inhibitors  help the body to lower blood glucose levels by blocking the breakdown of starches—such as bread, potatoes and pasta—in the intestine. They also slow the breakdown of some sugars, such as table sugar. Their action slows the rise in blood glucose levels after a meal. They should be taken with the first bite of every meal. Side effects could include gas and diarrhea.

DPP-4 Inhibitors is a new class of medication that prevents the breakdown of a naturally occurring compound in the body, GLP-1. By interfering in the process that breaks down GLP-1, DPP-4 inhibitors allow it to remain active in the body longer, lowering blood glucose levels only when they're elevated. Other positives about these medicines is that they don't cause weight gain and can be helpful control cholesterol levels.