What You Should Know About Drugs for Type 2 Diabetes

An overview of type 2 diabetes drugs

If a patient has type 2 diabetes, sometimes lifestyle changes -- healthier eating, becoming more active, and losing weight -- aren't enough to keep his blood sugar in his target range. If that's the case, he may need one or more types of prescription pills to help control his condition.

Several classes of oral diabetes drugs are designed to help keep blood sugar in check:

• Biguanides
• Meglitinides
• D-phenylalanine derivatives
• Thiazolidinediones
• Sulfonylureas
• Alpha-glucosidase inhibitors
• DPP-4 inhibitors

Here's what you need to know about each of them:

Biguanides

Metformin (brand name: Glucophage) is a biguanide (by-GWAN-ide) that acts in several ways to control diabetes. It helps a patient's body use insulin better, and it helps the liver make less sugar and lowers the amount of sugar his body absorbs from food. This inexpensive drug, available since the mid-1990s, is commonly taken twice a day. A once-a-day, slow-release pill is also available. Metformin may also decrease LDL or "bad" cholesterol and triglycerides. This is often the first choice of treatment for older adults with type 2 diabetes.

Potential side effects: Metformin may trigger nausea and diarrhea, though this is less likely if a patient takes the drug with food or if he starts with a low dosage that's gradually raised as needed. This medication isn't recommended for people with certain kidney or liver problems, and those who take it should have regular kidney function checks, especially since the elderly are more prone to reduced kidney function.

It's not recommended for people over the age of 80 unless they've had a kidney function test. "I'm cautious about using metformin in my very elderly patients because of kidney problems," says endocrinologist Karen Earle, medical director of Center for Diabetes Services at California Pacific Medical Center in San Francisco. "When I do prescribe it to patients over 80, I make sure they don't just have a blood test but a more precise urine test to check kidney function."

Some people develop anemia (a blood disease) as a result of taking this drug, so a blood test in the first few months of therapy is also wise. Metformin may not be suitable if a patient has severe heart disease or drinks alcohol to excess.