Diabetes Drugs Compared
Avandia Has Lowest Treatment Failure Rate, but Each Drug Had Pros and Cons
Dec. 6, 2006 -- A new study comparing three major diabetes drugs -- Avandia,
Glucophage (metformin), and Micronase (glyburide) -- shows that all three drugs
have pros and cons to consider.
Patients and their doctors should weigh those potential risks and benefits
when choosing between the drugs, the study concludes.
The research, published in The New England Journal of Medicine,
looked at 4,360 adults with type 2 diabetes. That's the most common type of
diabetes in adults.
It found Avandia had the lowest treatment failure rate -- 15% -- compared
with 21% for Glucophage and 34% for Micronase.
But Avandia was linked to greater weight gain, higher levels of LDL
("bad") cholesterol, and more swelling than the other two drugs.
However, a journal editorial suggests that metformin, which is sold
generically and under several names, might be the "logical" starting
point for diabetes drug treatment.
Researcher Steven Kahn, MB, ChB, of the University of Washington and the
Veterans Affairs Puget Sound Health Care System, and colleagues did the
Participants were mainly white and obese. They were, on average, in their
The patients were assigned to take one of three diabetes drugs -- Avandia,
Glucophage, or Micronase.
Glucophage is a brand-name version of metformin, which is also sold
generically and under other brand names including Glumetza, Fortamet, and
Riomet. Micronase is a brand-name version of glyburide, which is sold also
generically and as Diabeta.
The patients were followed for an average of four years.
The chance of drug failure was 32% lower with Avandia than with Glucophage
and 63% lower than with Micronase, based on the study's threshold for drug
However, all the drugs had pros and cons.
Though Avandia was linked to greater weight gain, higher LDL levels, and
more swelling, it also came with extra benefits.
Patients taking Avandia were less likely to have gastrointestinal problems
than those taking metformin. They were less likely to have blood sugar that was
too low than patients taking glyburide.
Avandia is the newest and most expensive of the three drugs.
"The potential risks and benefits, the profile of adverse events, and
the costs of these three drugs should all be considered" in choosing
diabetes drugs, conclude the researchers.
The study was funded by Avandia's maker, GlaxoSmithKline.
High Dropout Rate
Editorialist David Nathan, MD, writes that the findings' clinical
significance may be "less impressive" than it seems at first
Nathan works at the Diabetes Center and Department of Medicine at Boston's
Massachusetts General Hospital and Harvard Medical School.
He points out that a "surprisingly high" proportion of patients quit
the study (about 40%).
That "weakens the results," Nathan writes. He notes that patients
left the study for various reasons, not just because of drug side effects.
Nathan concludes that metformin "remains the logical choice" when
starting diabetes drug therapy, given Avandia's "modest" blood sugar
benefit, risk of fluid retention and weight gain, and higher cost.
Nathan reports having received grants from Novo Nordisk, which makes
diabetes care products, and drug company Sanofi-Aventis, the maker of Diabeta.
He has also received GlaxoSmithKline funding for an educational program.