Drug treatment of type 2 diabetes mellitus in patients for whom metformin is contraindicated

Metformin is considered an initial drug of choice for type 2 diabetes mellitus by leading recommendations. When contraindications to its use exist or patients cannot tolerate it due to adverse effects, clinicians have a variety of other classes of agents to treat hyperglycemia associated with type 2 diabetes mellitus. Each class of agent has its own benefit and safety profile. There are numerous factors to consider when selecting another agent in lieu of metformin including, but not limited to, overall efficacy in A(1c) reduction, adverse effect profile, cost, and patient preference. The number of factors influencing the decision process presents challenges and often no one specific agent is ideal. Each pharmacotherapeutic class of agents alternative to metformin for the treatment of hyperglycemia in type 2 diabetes mellitus as initial monotherapy is reviewed.