This Diabetes Drug is an Oldie but a Goodie

Type 2 diabetes drug Metformin, may still be best

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) While you may think that newer medications improve upon older ones, it turns out that might not be the case when it comes to diabetes.

It appears Metformin, a type 2 diabetes medication in use for over 15 years is cheaper, works just as well, and has fewer side effects than those developed more recently.

Through a review of past studies, researchers from Johns Hopkins University found that Metformin, first approved by the FDA in 1995, works well controlling blood sugar and reducing the risk of side effects, including weight gain and high levels of cholesterol.

dailyRx Insight: The generic version of Metformin is cheaper and still works.

According to Wendy L. Bennet, M.D., M.P.H., assistant professor in the Division of General Internal Medicine at the Johns Hopkins University School of medicine and leader of the study, metformin is "tried and true." Not only is the drug cheaper, she says, but it also works for the vast majority of diabetes patients (diabetics who also have severe kidney disease may need to steer clear of the drug).

For their study, Bennet and colleagues looked at more than 160 previously published studies that analyzed the effectiveness, safety, and long-term outcomes of various diabetes drugs. The drugs examined in the study included: metformin (Glucophage®, Fortamet®, and others), second-generation sulfonylureas (Amaryl®, Glucotrol®, and others), thiazolidinediones (Avandia®, Actos®), meglitinides (Starlix®, Prandin®), DPP-4 inhibitors (Januvia®, Onglynza®), and GLP-1 receptor agonists (Byetta®, Victoza®).

Because there weren't many long-term studies, especially of more recently developed medications, the researchers found no drug or drug combo that improved long-term outcomes.

Even though the majority of drugs were just as good at reducing blood sugar, metformin had the least side effects. Patients can experience some gastrointestinal problems from taking metformin, but this can be prevented by starting with low doses and taking the drug with food.

The findings from the review also show that patients who take sulfonylureas and meglitiniedes face an increased risk of low blood sugar. Patients' risk of heart failure, weight gain, and fracture increased when taking thiazolidineiones.

Unlike metformin, newer medications for type 2 diabetes do not come in generic form, meaning that they cost much more than older drugs. For example, Januvia costs almost 18 times as much as metformin ($6.42 per pill versus 35 cents per pill).

Despite finding that all the drugs did their job of reducing levels of blood sugar, Bennet says more research is needed in order to see if these drugs are beneficial to patients in the long term.

Because many drugs have been on the market for such a short period of time, we do not know the long-term effects, or even some short-term side effects. As such, researchers need to conduct longer studies involving high-risk patients, concludes Bennet.

In the United States each year, nearly 26 million individuals are affected by diabetes, with about seven million people going undiagnosed. Diabetes is a chronic metabolic disease with no cure in which a person has either high or low blood sugar, either because the body does not produce enough insulin or because cells do not respond to the insulin that is produced. There are three main types of diabetes: Type 1, Type 2 and Gestational. Several groups of drugs, mostly given by mouth, are effective for Type 2. The therapeutic combination in Type 2 may include insulin. The great advantage of injected insulin in Type 2 is that patients can adjust the dose according to blood glucose levels, usually measured with a simple meter. Along with the presence of physical symptoms, a common blood test known as the A1c can test for the disease.

The Johns Hopkins study appears online in the Annals of Internal Medicine

Reviewed by: 
Review Date: 
March 15, 2011
Last Updated:
March 16, 2011