Can I Switch to Insulin?
I want to switch to insulin, but my doctor says there is no dose small enough for me. I was diagnosed with type 2 diabetes in 2000. I have been on oral meds, including glyburide, since the end of the first year. My A1C is below 6. I do get lows with my orals, usually when I wake up in the morning. My highs tend to be under 200. I find it hard to believe I have to let my diabetes get worse in order to get the medication that would be best for my body. Is it true that there is not an insulin dose low enough for me? Cynthia Quill, Cayuga, New York
Craig Williams, PharmD, responds: If you are achieving good glucose control with a sulfonylurea, there would be no benefit to switching to insulin. There has been more attention given recently to the idea of people with type 2 diabetes beginning insulin injections early on, as a result of some disappointing results in the Avandia trials last year. The studies' results prompted a reevaluation of how we approach the medication management of type 2 diabetes. Other oral agents, including Januvia, are new enough that, while there is reason to feel excited about the prospects for their long-term use, we don't yet have the years of experience that we have with agents like metformin that have been around longer.
While insulin is tried and true, there are no clear data to show that insulin offers any extra protection or benefit compared with a doctor-recommended first-tier oral agent like glyburide. The first-tier agents, as determined by an expert panel convened by the American Diabetes Association, are those recommended for initial diabetes treatment. They include sulfonylureas (like glyburide and glipizide), metformin, and insulin. As long as the same degree of control is achieved, a sulfonylurea works fine.
While insulin is a great drug for many patients, it can have problems of its own (chiefly, hypoglycemia), and you shouldn't feel as if you are missing out if you achieve good glucose control with recommended oral agents. If the first-tier therapies don't work, other medications should be added to achieve glycemic control. The risk of poorly controlled blood glucose outweighs concerns about newer therapies.
Your blood glucose is already well controlled, and insulin may result in even more hypoglycemia for the same level of control. Therefore, I agree here that with an A1C of less than 6 and some occasional hypoglycemia already, there is no reason for you to switch to insulin, even with an occasional high blood glucose level above 160 mg/dl.