There aren't really any other drugs that do the same thing as metformin (which is inhibit glucose production in the liver) but there are several other classes of drugs that do other things. There are the sulfonyluria's like Amaryl and Glucotrol XL (taken once a day) that stimulate beta cell production helping your pancreas to make more insulin. There is also Starlix and Prandin that act similarly but you have to take them before each meal. Then you have the TZDs such as Actos and Avandia that help with insulin resistance. Plus varying combo's of each like Actos plus Met, Avandamet, Avandaryl, etc etc. It's overwhelming and confusing. There are other options, but they don't do exactly what Metformin does. Metformin is really the gold standard first line drug for Type 2 Diabetes. Hope that helps!