An independent, government-financed review of many diabetes drugs says cheaper generics are as effective and as safe as brand-name treatments.
"Compared with newer, more expensive agents ... older agents have similar or superior effects on
blood sugar control and other cardiovascular risk factors" such as high blood pressure and high cholesterol, says a report published online Monday by the
Annals of Internal Medicine
The study was conducted by researchers at medical and public health schools at Johns Hopkins University in Baltimore and Washington University in St. Louis. The research was financed by a unit of the Department of Health and Human Services. None of the researchers reported corporate conflicts of interest.
The analysis comes two weeks before a Food and Drug Administration
advisory panel looks into allegations of
higher cardiovascular risk linked to Avandia from
The new study says generic metformin, a common first line of defense, "seemed to have the best profile of benefit to risk." Metformin belongs to the biguanide drug class, which causes the liver to produce less glucose and which makes muscles more sensitive to sugar-burning insulin.
Other older drugs that performed well are sulfonylureas, which stimulate the pancreas to produce more insulin. The biggest drawback for this class was the risk of hypoglycemia, a dangerous drop in blood sugar.
Compared to newer drugs, the researchers say metformin and sulfonylureas have the advantages of "lower cost, longer use in practice and more intensive scrutiny in long-term trials" that measure key safety outcomes.
However, they say more long-term studies are needed to determine which drugs are safest when assessing risks such as heart attacks, kidney disease and heart-related deaths. The study "found no definitive evidence" on comparing how several drug classes affected heart-related deaths, heart damage or other causes of death.
The study included newer drugs, such as thiazolidinediones, which include Avandia and
Actos. These drugs make muscles more sensitive to insulin and encourage the liver to produce less glucose.
Researchers also reviewed alpha-glucosidase inhibitors, which block the breakdown of starches in the intestines. Examples include Precose and Glyset, from
. They also examined meglitinides, like Prandin from
and Starlix from
, which stimulate insulin production in the pancreas.
The research appears at a time when many companies are
developing new diabetes treatments and seeking FDA approval for
earlier use of newer drugs. Some are selling or developing combination pills, including those that contain new drugs plus metformin.
As the number of diabetes cases grows, doctors often prescribe more than one drug to control the disease, while insurers are trying to restrain costs. The pharmacy benefit manager
recently reported that diabetes drugs were a major source of rising health care expenditures.
"An epidemic of diabetes, along with more aggressive treatment, could result in a near 70% increase in spending on endocrine and diabetes therapies from 2007 through 2009," Medco said in May. Greater use of noninsulin drugs as well as insulin reflects "the expanding prevalence of diabetes and the increased use of multiple-drug therapies for blood-glucose control," Medco said.
said Monday that the
report "shows that lower-cost, older medications work just as well for most people." The magazine, published by Consumers Union, issued a diabetes medication guide that was based primarily on the new study.
report focused on people with Type 2 diabetes, the most common form of the disease in which the body doesn't make enough insulin or doesn't adequately process insulin. The many oral diabetes drugs don't help people with Type 1 diabetes. With Type 1 diabetes, people are unable to produce insulin.
The researchers looked at 216 clinical trials and two systematic reviews of diabetes research, as well as unpublished data from companies and the FDA. They concede their study has limitations. Many of the clinical trials that they reviewed lasted less than 12 months.
"Ideally, therapeutic decision-making should be based on long-term effectiveness," they wrote.
Their article was affected by a paucity of studies making head-to-head comparisons, especially when patients were taking more than one blood-sugar control drug. The review of clinical studies revealed "inconsistent" reporting of side effects, "making comparisons across studies difficult," the authors say.
In addition, they cut off their research in January 2006, meaning they didn't examine the newest drugs such as Januvia from