Type 2 Diabetes Drugs Fail to Improve the Most Serious Long-Term Complications

Are the drugs prescribed for Type 2 diabetes effective? The answer to this question depends on how the word "effective" is defined.

Below is a list of the 16 drugs, in 9 different pharmacologic classes, that are approved by the Food and Drug Administration (FDA) for the management of Type 2 diabetes. All of these drugs were approved because they lower blood sugar (glucose) and glycated hemoglobin, or hemoglobin A1c (HbA1c) levels in the blood. HbA1c is used to gauge the average blood sugar level over a period of time. Both of these tests are used to diagnose, monitor, and are the basis to approve new drugs to treat Type 2 diabetes. If these two tests are measures of effectiveness, then unquestionably all of the drugs approved by the FDA for Type 2 diabetes are effective.

But diabetes also puts people at greater risk of long-term complications, such as heart disease, stroke and peripheral vascular disease (macrovascular risks), and there is no evidence that the Type 2 diabetes drugs currently on the market reduce these risks.

In fact, the FDA requires that the professional product labels, or package inserts, for all these drugs warn prescribers that: "There have been no clinical studies establishing conclusive evidence of macrovascular risk reduction with … any … oral antidiabetic drug."

Mistaken beliefs

Patients and physicians alike might assume that successfully lowering blood sugar level means that a patient’s Type 2 diabetes is under control and that in turn the risk of developing the devastating complications of the disease has been reduced. As mentioned above, this view is mistaken.

The FDA’s standard for effectiveness — reducing blood sugar and HbA1c — is an inadequate way to determine which drugs should be approved. The FDA should therefore base Type 2 diabetes drug approval on the ability of the drug to lessen long-term risks, such as heart disease.

A better way

Patients do not need more diabetes drugs that lack convincing evidence of effectiveness, risk reduction of Type 2 diabetes complications and long-term safety.

A change in dietary habits and additional exercise to control weight can both prevent and control Type 2 diabetes.

Our view is that the FDA should require evidence that new drugs reduce the long-term risks associated with Type 2 diabetes as a condition of approval.

The agency has taken a small step in this direction by requiring that the manufacturers prove that new Type 2 diabetes drugs do not present an unacceptable level of heart risk but they have not required that such studies be completed before marketing.

However, there are questions as to whether or not these new requirements will identify new drugs with intolerable levels of risk.

What You Can Do

Do not stop taking any diabetes medication without first consulting the prescriber.

Patients who have been newly diagnosed with Type 2 diabetes should try a change in diet and an increase in exercise before turning to treatment with medication. One reason that such lifestyle changes are not heavily promoted to prevent and manage Type 2 diabetes may be that the only one who would profit would be you.

For patients who already have Type 2 diabetes, a change in diet and exercise can help control this condition.

Drugs for Type 2 Diabetes 
(This list does not include the brand names of combination drug products)

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Updated 4/4/2012