Examples

Metformin is also available as a combination pill, combined with the sulfonylurea medicine glyburide (Glucovance), glipizide (Metaglip), or glimepiride (Duetact); the thiazolidinedione medicine pioglitazone (Actoplus Met) or rosiglitazone (Avandamet), the DPP-4 inhibitor medicine sitagliptin (Janumet), and the meglitinide medicine repaglinide (PrandiMet).

How It Works

Biguanides lower blood sugar by:

• Decreasing the amount of sugar produced by the liver.
• Increasing the amount of sugar absorbed by muscle cells.
• Decreasing the body's need for insulin.

Metformin does not cause the pancreas to produce more insulin. It should not cause low blood sugar (hypoglycemia) or weight gain, unless it is taken in combination with medicines that do. Some people may lose weight when starting this medicine.

Why It Is Used

These medicines are used to treat insulin resistance common to people with prediabetes, type 2 diabetes, and polycystic ovarian syndrome. It has also been studied for use in cancer prevention and treatment, but more research is needed.

How Well It Works

Type 2 diabetes is a disease that can get worse over time, so medicines may need to change.

Diabetes medicines work best for people who are being active and eating healthy foods. Studies have suggested that metformin lowers hemoglobin A1c by 1% to 2%.¹

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

• Usually the benefits of the medicine are more important than any minor side effects.
• Side effects may go away after you take the medicine for a while.
• If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Call 911 or other emergency services right away if you have:

• Trouble breathing.
• Hives.
• Swelling of your face, lips, tongue, or throat.

Call your doctor right away if you have:

• Symptoms of lactic acidosis, such as rapid breathing, excessive sweating, cool and clammy skin, sweet-smelling breath, belly pain, nausea or vomiting, and/or confusion.