It appears someone finally decided to take a look at the effectiveness and benefits of older diabetes drugs (such as metformin) compared with newer, more expensive ones (such as Avandia). Dr. Shari Bolen of Johns Hopkins University studied various medical databases and found 216 relevant studies and two systematic reviews. According to Reuters:

Older drugs controlled blood sugar levels about as well as the thiazolidinediones [Avandia] did. There were some differences, however, in other effects.

Thiazolidinediones were the only drugs that increased HDL “good” cholesterol levels, but they also increased LDL “bad” cholesterol levels. Metformin reduced LDL cholesterol levels, while the other agents appeared to have no effect on cholesterol levels.

With the exception of metformin, the drugs generally increased body weight by 1 to 5 kilograms. Compared with other drugs, sulfonylureas and repaglinide were tied to increased risks of low blood sugar, thiazolidinediones were linked to heart failure, and metformin raised the risk of stomach and intestinal problems.

“Each oral diabetes agent is associated with adverse events that counterbalance its benefits,” the researchers conclude. “Overall, metformin seemed to have the best profile of benefit to risk.”