Some people who have type 2 diabetes can achieve their target blood sugar levels with diet and exercise alone, but many also need diabetes medications or insulin therapy. The decision about which medications are best depends on many factors, including your blood sugar level and any other health problems you have. Your doctor might even combine drugs from different classes to help you control your blood sugar in several different ways.
Generally, metformin is the first medication prescribed for type 2 diabetes. It works by improving the sensitivity of your body tissues to insulin so that your body uses insulin more effectively. Metformin also lowers glucose production in the liver. Metformin may not lower blood sugar enough on its own. Your doctor will also recommend lifestyle changes, such as losing weight and becoming more active.
These medications work like sulfonylureas by stimulating the pancreas to secrete more insulin, but they’re faster acting, and the duration of their effect in the body is shorter. They also have a risk of causing low blood sugar, but this risk is lower than with sulfonylureas. Weight gain is a possibility with this class of medications as well. Examples include repaglinide (Prandin) and nateglinide (Starlix).
Like metformin, these medications make the body’s tissues more sensitive to insulin. This class of medications has been linked to weight gain and other more-serious side effects, such as an increased risk of heart failure and fractures. Because of these risks, these medications generally aren’t a first-choice treatment. Rosiglitazone (Avandia) and pioglitazone (Actos) are examples of thiazolidinediones.
These medications help your body secrete more insulin. Examples of medications in this class include glyburide (DiaBeta, Glynase), glipizide (Glucotrol) and glimepiride (Amaryl). Possible side effects include low blood sugar and weight gain.
5. GLP-1 receptor agonists
These medications slow digestion and help lower blood sugar levels, though not as much as sulfonylureas. Their use is often associated with some weight loss. This class of medications isn’t recommended for use by itself. Exenatide (Byetta) and liraglutide (Victoza) are examples of GLP-1 receptor agonists. Possible side effects include nausea and an increased risk of pancreatitis.
6. SGLT2 inhibitors
These are the newest diabetes drugs on the market. They work by preventing the kidneys from reabsorbing sugar into the blood. Instead, the sugar is excreted in the urine. Examples include canagliflozin (Invokana) and dapagliflozin (Farxiga). Side effects may include yeast infections and urinary tract infections, increased urination and hypotension.
7. DPP-4 inhibitors
These medications help reduce blood sugar levels, but tend to have a modest effect. They don’t cause weight gain. Examples of these medications are sitagliptin (Januvia), saxagliptin (Onglyza) and linagliptin (Tradjenta).