Old Diabetes Drug Has Advantages
Report: Metformin Effective With Fewer Side Effects Than Newer Drugs
July 16, 2007 -- Most type 2 diabetes drugs are equally effective for
lowering blood sugar, but the generic drug metformin has fewer side effects
than several newer, pricier medications, a government report finds.
Metformin users are less likely to gain weight than type 2 diabetes patients
who take Avandia, Actos, or other newer medications, researchers concluded, and
they are more likely to show improvements in so-called "bad"
The report was issued by the Agency for Healthcare Research and Quality
(AHRQ), a division of the Department of Health and Human Services.
Researchers from Johns Hopkins University’s Evidence-based Practices Center
reviewed 216 previously published studies in their effort to compare the
effectiveness, risks, and costs of older and newer diabetes pills.
The study, which was made public today, will appear in the Sept. 18 issue of
the Annals of Internal Medicine.
Diabetes Drugs: Old and New
All diabetes medications help to lower blood sugar, but they work in
different ways. Metformin and drugs in the class known as sulfonylureas, such
as Glipizide or Glyburide, are among the least-expensive oral diabetes
medications because generic versions are now available.
The newer oral medications Avandia (by GlaxoSmithKline) and Actos (by Takeda
Pharmaceuticals) -- both in the drug class thiazolidinedione (TDZ) -- are now
among the most widely prescribed diabetes drugs.
Among the highlights of the report:
- Metformin was one of the few diabetes drugs not associated with an increase
in weight. The report noted that other widely prescribed diabetes drugs have
been shown to increase body weight by an average of 2 to 11 pounds.
- Use of metformin was associated with a decrease in blood levels of
low-density lipoprotein, or "bad" cholesterol, while use of the TDZ
class of drugs raised levels good cholesterol and had a harmful effect on LDL
- Amaryl, Glucotrol, and other sulfonylurea drugs were more likely to cause
unsafe drops in blood sugar (hypoglycemia) than other diabetes drugs.
- Patients on metformin or the drug acarbose complained of diarrhea and other
gastrointestinal problems more than users of other drugs. Patients who took
only metformin were more likely to experience these digestive problems than
patients who took lower doses of metformin in combination with other diabetes
- Use of Avandia and Actos was associated with a greater risk of congestive
Diabetes Drugs and the Heart
Concerns about heart failure risk led the FDA to announce last month that
labels for Avandia and Actos will soon carry a "black box" warning to
alert doctors and patients to the risk. A highly publicized study recently
linked Avandia to an increased risk of death from heart attacks, but the drug's
manufacturer has challenged the findings.
In testimony before a congressional committee in June, a GlaxoSmithKline
spokesman said there is no evidence that Avandia carries more heart risk than
other drugs of its class. And an interim report from an ongoing
company-sponsored study assessing Avandia's impact on the heart found the data
on heart attack risk to be inconclusive.