A recent study has concluded that acarbose and metformin can be used as effective therapies in people with type 2 diabetes who are poorly controlled with a sulfonylurea agent alone. Better glycemic control was achieved by patients in the study who also took acarbose or metformin, as opposed to just a sulfonylurea.
One disadvantage of the acarbose combination is the frequency of gastrointestinal side effects, but these effects decline after a few days. (Mitase Bayraktar et al., Diabetes Care 19:252-4, Mar. 1996)