Practical considerations and guidelines for dosing sulfonylureas as monotherapy or combination therapy

Oral antidiabetic agents are the initial and most commonly used therapy for type 2 diabetes mellitus. To effectively utilize the oral antidiabetic agents, familiarity with the efficacy and side effects of each agent is essential so that strategies for effective therapy with 1 or more agents can be developed when transitioning is needed either with monotherapy or to combination therapy with another antidiabetic agent.

The purposes of this article were to review the efficacy and adverse-event profile of sulfonylureas, the most widely used class of oral antidiabetic agents in the United States, and to provide a simple set of guidelines for use in transitioning patients between sulfonylureas or to combination therapy.

A comprehensive search of the MEDLINE and PubMed databases for the years 1966 to present and a thorough review of abstracts of recently presented clinical trials were used to identify relevant literature on dosing conversion and equivalence between sulfonylureas. Search terms used were as follows: sulfonylureas, dosing conversion, equivalence, glyburide, glipizide, glimepiride, and combination therapy. Strategies are provided for switching patients between sulfonylureas so that switching within the sulfonylurea class or to a combination tablet can be accomplished efficaciously and safely. Recommendations for dosing conversion were based on the results of the literature and abstract search, manufacturer recommendations for each available agent, and the author's clinical experience.

When switching between agents or starting combination therapy, it is important to monitor for hypoglycemia. Fasting serum glucose levels and glycosylated hemoglobin should also be monitored to determine the optimal dose of sulfonylurea for each patient Patients not achieving adequate control on a single agent should be transferred to combination therapy.

When transferring a diabetic patient to a combination tablet, improved compliance, cost savings, and better glycemic control may be achieved.