Diabetes Demands a Triad of Treatments
Oral Drugs continued...
Because SFUs can become less effective after 10 or more years of use, other drugs often are needed. Also, there is some controversy regarding SFUs; some of these agents have been shown in studies to contribute to increased risk of death from cardiovascular disease.
A newer class is the biguanides, including Metformin, which was approved by FDA in 1995. This drug acts by lowering cells' resistance to insulin, a common problem in Type II diabetes.
A third class is the alpha-glucosidase inhibitors, which include Precose, approved by FDA in 1995, and Miglitol, approved in 1996. These drugs slow the body's digestion of carbohydrates, delaying absorption of glucose from the intestines.
In January 1997, FDA approved the first in a new class of diabetes drugs, Rezulin. The new medicine helps Type II diabetics make better use of their own insulin by resensitizing body tissues to the insulin. Parke-Davis, a division of Warner-Lambert of Morris Plains, N.J., plans to begin marketing the drug by summer 1997.
"It will be useful in patients who, despite taking large doses of insulin, still are not achieving adequate glucose control," Misbin says.
Some oral drugs may be used in combination to improve blood sugar control. For example, FDA's Misbin says, Metformin, with an SFU, is particularly useful for Type II diabetics who are obese. "Type II patients who would ordinarily use (only) SFUs do not gain weight with Metformin," he explains. "(The combination) also is used for people taking SFUs but are no longer getting the SFUs' full effect. Studies show that when you add Metformin to a regimen of an SFU, you get a treatment that is better than either drug used alone."
Metformin makes users more sensitive to the body's naturally produced insulin and decreases excessive production of sugar by the liver, another characteristic of Type II diabetes.
The drugs are not without side effects. Metformin, for example, can cause serious cramps and diarrhea, and it can't be used in people with kidney problems. "So if you have to go on this drug, you need to have kidney function tests," Santiago says.