When it comes to treating type 2 diabetes, newer isn't necessarily better. In fact, older, less expensive drugs offer benefits that are similar or even superior, research shows.
In a federally funded project involving analysis of 218 studies, researchers compared the pros and cons of older oral drugs (second-generation sulfonylureas and metformin) with newer and more expensive antidiabetic drugs (thiazolidinediones, alfa-glucosidase inhibitors, and meglitinides). They also examined unpublished information from drug companies and the FDA. Here are some of their findings.
* Metformin is the best bet for safety and effectiveness, controlling diabetes as well as other agents without causing weight gain or hypoglycemia. It's also significantly less expensive than newer drugs.
* Metformin also lowers low-density lipoprotein (LDL) or "bad" cholesterol, by about 10 mg/dL, while the newer drugs rosiglitazone and pioglitazone increase LDL by about the same amount. However, these newer drugs slightly boost high-density lipoprotein ("good" cholesterol).
* Glimepiride, glipizide, glyburide, and repaglinide are most likely to cause hypoglycemia. Metformin and acarbose are more likely to cause gastrointestinal adverse reactions.
Marketed as Avandia, rosiglitazone has been linked in recent reports to an increased risk of myocardial infarction. Researchers say the evidence from this study isn't sufficient to settle the controversy.
This is the first major comparison of oral antidiabetic drugs in about 10 years.
Bolen S, et al., Systematic review: Comparative effectiveness and safety of oral medications for type 2 diabetes mellitus, Annals of Internal Medicine, September 18, 2007.