Limitations Of Diabetes Pharmacotherapy
Background: There are a wide variety of medications available for the treatment of hyperglycemia in diabetes, including some categories developed in recent years. The goals of this study were to describe the glycemic medication profiles in a cohort of adult patients enrolled in primary care, to compare the regimens with measures of glycemic control, and to describe potential contraindicated regimens.
Methods: One thousand and six subjects with diabetes cared for in community practices in the Northeast were interviewed at home at the time of enrollment in a trial of a diabetes decision support system. Laboratory data were obtained directly from the clinical laboratory. Current medications were obtained by direct observation of medication containers by a research assistant.
Results: The median age of subjects was 63 years; 54% were female. The mean A1C was 7.1%, with 60% of subjects in excellent glycemic control (A1C < 7%). Ninety percent of patients were taking 2 or fewer medications for glycemic control, with a range of 0 to 4 medications. Insulin was used by 18%. As the number of diabetes medications increased from 0 to 4, the A1C increased from 6.5% to 9.2% (p < 0.001). The association between glycemic control and number of glycemic medications was confirmed using logistic regression, controlling for potential confounders. Almost 20% of subjects on metformin or thiazolidenediones had potential contraindications to these medications.
Conclusion: Patients with diabetes cared for in primary care are on a wide variety of medication combinations for glycemic control, though most are on two or fewer medications. A greater number of diabetes medications is associated with poorer glycemic control, reflecting the limitations of current pharmacotherapy. One quarter of patients are on glycemic medications with potential contraindications.

Despite evidence that optimal diabetes care can result in reduced complications and improved economic outcomes, such care is often not achieved. Through the 1990s, the number of primary care visits among patients with diabetes listing at least 5 prescription medications increased from 18% to 30%, and the proportion of visits in which more that one medication for glycemic control was listed increased from < 1% to 17%. Oral hypoglycemic agent use increased from 45% to 53%, and combination therapy with insulin and an oral agent increased from 3% to 11%.

While there are a wide variety of options for pharmacotherapy of diabetes, there is no one recommended regimen. New classes of medications have been introduced since 1999, including the thiazolidenediones (TZDs), acarbose, and both ultra-short acting and 24-hour insulin analogues. It is not clear how the addition of these new medication classes has changed the landscape of pharmacotherapy of diabetes.

Our goals in this study were: 1) to describe the glycemic medication profiles and the associated level of glycemic control in a cohort of adult patients in primary care settings, and 2) to analyze the medication profiles for potential medication contraindications.