Epilepsy Drug Topamax Targets Diabetes
Topamax Appears to Correct Underlying Risk Factors
June 16, 2003 (New Orleans) -- For the first time, researchers say they have evidence that a drug can correct underlying risk factors that lead to the development of diabetes.
In a small study, the antiepileptic drug Topamax lowered levels of total cholesterol, blood glucose, and diastolic blood pressure, all components of the "prediabetic syndrome," reports Aaron I. Vinik, MD, PhD, director of the Strelitz Diabetes Research Institutes at Eastern Virginia Medical School in Norfolk. The prediabetic syndrome is the period before full-blown diabetes and also puts a person at a high risk for cardiovascular disease.
Topamax also appears to reverse some of the nerve damage that leads to a painful condition called peripheral neuropathy, one of the most common complications of diabetes, in which diabetic people often feel like their feet are being stabbed by needles or that their hands are on fire, he says.
The bottom line, Vinik tells WebMD, is that "this has given us the first opportunity to change the underlying biology of the disease as opposed to treating its symptoms."
There's still a long way to go, he stresses, noting that he has only studied 11 patients.
"But all the patients in the study improved, so even though the numbers are small, the findings are powerful," he says.
In a previous trial, Vinik's team found that Topamax appeared to relieve the symptoms of numbness and pain that characterize peripheral neuropathy. But what was even more striking, he says, is that all the patients in the study unexpectedly lost weight and experienced a drop in cholesterol and diastolic blood pressure levels.
"There was something much more interesting happening to these patients than relief of pain," he says. "It seemed like [Topamax] would possibly address both the inability of the body to process glucose properly and changes in function."
More than 17 million Americans have diabetes, a third of whom are unaware that they have it. An additional 16 million are thought to suffer from prediabetes, meaning they have blood sugar levels that are higher than they should be but are not yet high enough to be considered diabetes.
Reporting at the American Diabetes Association's 63rd Annual Scientific Sessions, Vinik says he studied 11 patients, whose average age was 59 years, who suffered from type 2 diabetes and peripheral neuropathy.
Standard antidiabetic therapy was used to stabilize blood sugar levels, and the patients were weaned off pain medication. Then, all the patients were administered Topamax once a day for 96 days.
By the end of the study, patients reported a reduction in pain that was comparable to that seen with the drug that is now considered the gold standard for treating peripheral neuropathy, Vinik says.
More importantly, "Nerve fibers actually grew back," he says. "That was the most dramatic observation. We seemed to be reversing the disease process that leads to neuropathy."
In addition, total cholesterol dropped by about 10% and diastolic blood pressure dove by 10 points, "more than you can expect with some standard blood-pressure-lowering medications," Vinik says.
Also, levels of hemoglobin A1C, a standard measure of blood sugar, decreased from an average of 7.8% to 7.1% -- very near the American Diabetes Association's recommended target of 7.0%, he says.