Data from a major new Canadian primary-care study show that the combination of rosiglitazone maleate (Avandia®) and low-dose metformin resulted in a significant decrease in A1C compared to metformin alone.
The study authors conclude that rosiglitazone and low-dose metformin combination therapy is more efficacious than the usual approach of maximizing the dose of metformin monotherapy, and is an effective strategy for helping type 2 diabetes patients reach recommended blood sugar targets.
The study also demonstrates that the addition of rosiglitazone to diabetes therapy resulted in low rates of hypoglycemia, high adherence and patient satisfaction.
"Although physicians understand the importance of reaching treatment targets, they are often hesitant to put their patients, especially the moderately controlled ones with an A1C close to 7.0%, on more aggressive therapy out of concern for side effects, such as hypoglycemia. Given the fact that any reduction in A1C can reduce the risk for the micro and macrovascular complications of diabetes, we need to overcome this treatment inertia," says Dr. Lawrence Leiter, Head of Endocrinology at St. Michael's Hospital in Toronto and study co-author. "These study findings are exciting because the results offer physicians relevant evidence for a therapeutic strategy that helps even a relatively well controlled patient achieve stringent blood sugar targets safely and effectively."
The Rosiglitazone Evaluation: Advancing Canadian Treatment of Type 2 DM (REACT2 Diabetes) study enrolled 705 patients in 80 primary care practices in Canada. Among the key findings:
· Adding rosiglitazone to low dose metformin and lifestyle modification, instead of maximizing the metformin dosage, resulted in a significant mean reduction in A1C from 7.5% to 7.0%.
· Adding rosiglitazone alone to lifestyle modification resulted in a significant mean reduction in A1C of 0.62% down to 6.8%.
· Even patients with moderately controlled blood sugar levels (7.3% A1C) achieved optimal targets with rosiglitazone (alone and in combination therapy).
· Overall, there was negligible reporting of hypoglycemia and less than five% of study participants reported an adverse event. The few reported were mild to moderate in severity and did not typically result in the discontinuation of the study medication.
· The greatest improvement in patient satisfaction over the course of the study was noted in the rosiglitazone treatment groups.
"Most people with type 2 diabetes are treated in the primary care setting. It is a complex and difficult to treat disease and with prevalence on the rise, this is only going to put additional pressure on our family physicians. As such, it is necessary that effective management strategies be demonstrated in primary care," says Dr. Stewart Harris, Associate Professor, Schulich School of Medicine and Dentistry, the University of Western Ontario and co-author of the study. "REACT2 confirmed that rosiglitazone, alone and in combination therapy with low-dose metformin, is effective and safe for patients in daily practice and a good option for physicians to get their moderately controlled patients to treatment targets quickly, safely and effectively."
REACT2 Diabetes, a phase IV, open-label, randomized, parallel group, multicentre study, was conducted to evaluate the efficacy and safety of rosiglitazone alone and in combination with metformin in the primary-care setting. The primary efficacy endpoint was mean change in A1C from baseline at week 32. The patients were randomized into four treatment groups within two cohorts. Cohort 1 consisted of drug-naďve patients who were treated with lifestyle modification only, or rosiglitazone and lifestyle modification (total = 459 patients).
Cohort 2 consisted of metformin-treated patients who were treated with metformin and lifestyle modification, or metformin and rosiglitazone and lifestyle modification (total = 236 patients).
Rosiglitazone maleate (Avandia®) used alone, or in combination with metformin or a sulfonylurea, along with diet and exercise helps to control blood sugar. Rosiglitazone directly targets insulin resistance and improves beta-cell function, underlying causes of type 2 diabetes.
When combined with metformin, which works primarily by reducing the amount of sugar produced by the liver, these two drugs with complementary modes of action, can help patients achieve enhanced glucose control, which in turn may slow disease progression and reduce the risk of long-term complications. The most common side effects reported in clinical trials with rosiglitazone were upper respiratory tract infection, headache, and back pain. Rosiglitazone is not for everyone. Rosiglitazone is not recommended for patients with severe heart failure or with serious liver disease.