Drug therapies for type 2 diabetes are an important part of treatment. Take the time to learn as much as possible about all the medications you are taking to help avoid serious side effects.
Drug Therapies for Diabetes
Sulfonylureas and biguanides are oral hypoglycemic drugs used in treating type 2 diabetes. They were initially introduced for clinical use in the late 1950s.
Sulfonylureas
These drugs work by stimulating insulin release from the pancreas, and include drugs such as glipizide, glyburide, tolbutamide and chlorpropamide.
Biguanides
These drugs do not stimulate insulin release. Instead, they work mostly by lowering the amount of glucose released from the liver, thereby lowering blood glucose levels in people with type 2 diabetes. Low blood sugar (hypoglycemia) will not occur with biguanides, when used without other medications.
With very few exceptions, metformin is the only biguanide used today. Your kidney function must be measured, with blood tests, before starting this treatment.
This is because a rare and possibly fatal condition called "lactic acidosis" can occur with low kidney function.
New drugs introduced in the 1990's
- Apha-glucosidase inhibitors:
Alpha-glucosidase inhibitors were introduced in the 1990s. The two types currently available are acarbose and miglitol. These agents work by slowing the absorption of carbohydrates (complex sugars) from the intestine, which decreases the rise in blood glucose. There are no changes in insulin release from the pancreas with these agents, so when used alone, hypoglycemia will not occur. The drugs are taken just before eating. The major side effects of these agents relate to problems with the gastrointestinal tract: flatus (gas), diarrhea, and abdominal pain may all occur, although these problems may be diminished by starting the drug at low doses.
- Thiazolidinediones:
Another class of drugs is thiazolidinediones, also known as "insulin sensitizers." These agents work by improving one of the fundamental problems in type 2 diabetes - insulin resistance. Thiazolidinediones help your body use its own insulin more effectively by making the cells more sensitive to insulin.
After eating, insulin is required to move glucose from the bloodstream into the body's cells. Thiazolidinediones work by making the tissue more sensitive to insulin's actions, thereby allowing more glucose to enter the tissue, which lowers blood glucose. There are now two of these agents available and more are being developed. Since insulin is not stimulated, hypoglycemia is rare when these agents are used alone. Hypoglycemia is most likely to occur when thiazolidinediones are used in combination with sulfonylureas or insulin.
The first thiazolidinedione introduced in the United States was troglitazone Rezulin), which was associated with rare but severe liver toxicity and subsequently removed from the market. The two newer thiazolidinediones - rosiglitazone and pioglitazone - have not, as yet, been shown to directly cause severe liver problems. However, frequent monitoring of liver enzymes with blood tests will help reduce the risk of any liver problems.
- Meglitinides:
The final class of drugs for the treatment of type 2 diabetes are the meglitinides. Like sulfonylureas, these agents stimulate insulin secretion. The first meglitinide, called repaglinide, is very short acting and is taken before each meal. Since the insulin stimulation from this drug occurs for such a short period of time, hypoglycemia may be less of a problem than it is with traditional sulfonylureas. More meglitinides are currently being developed.
