By: Ben Eastman
There is a new medication for people with type 2 diabetes on insulin that could help reduce, and in a few cases possibly eliminate, the need for insulin. The drug appears to resensitize the body to insulin and makes it easier for glucose to be absorbed from the bloodstream.
The medication, Trog-litazone, was recently approved by the Food and Drug Administration’s (FDA) scientific advisory board. The FDA is not required to follow the advisory board’s recommendations when granting clearance to a medication, but it usually does.
The medication is a “truly novel approach,” says the FDA’s Dr. Solomon Sobel before the FDA board that voted unanimously to support the drug.
Troglitazone is produced by Parke-Davis and, if cleared by the FDA, will be marketed under the name Rezulin. It is expected that Rezulin will be available in early March of 1997.
Troglitazone is the only drug to deal directly with the cause of type 2 diabetes and its key symptom-the gradual loss of naturally occurring insulin’s effectiveness.
Two studies on Troglitazone, involving 573 subjects, showed that 56 percent of those on the drug achieved HbA1c levels of less than 8%. According to the ADA, 7% or lower is “normal” and 8% or lower is “desirable.” These studies also showed that patients taking 400 mg reduced their daily insulin requirements by 58 percent. In addition, 15 percent were able to stop all insulin injections and 70 percent reduced their daily dose of insulin by more than half.
Jeff Baum, spokesman for Warner Lambert, parent company of Parke-Davis, says that Rezulin is the “only drug that lowers blood glucose while at the same time reducing, and possibly eliminating, the need for insulin. It improves glycemic control, thereby stopping the underlying cause of type 2 diabetes.”
Rezulin’s exact mechanism of control remains a bit of a mystery, however. Dr. David Ehrman, a Troglitazone researcher at the University of Chicago Medical Center, believes it may “relate to the metabolism of free fatty acids beyond the (insulin) receptor level.”
Dr. Anne L. Peters, director of Clinical Diabetes at UCLA and associate professor of medicine, believes that it may stimulate insulin reactive proteins in the nucleus that help remove glucose from the blood, thereby decreasing the need for insulin.
Peters explains that the drug works by making faulty insulin receptors work more effectively. Therefore, people with type I diabetes are not likely to derive any benefit from the drug. But Keith Campbell, RPh, FACP, CDE, points out that it may eventually be used for people with impaired glucose tolerance, a condition that always precedes type 2 diabetes. He suggests that if these patients are put on Rezulin it could halt the development of their condition into type 2 diabetes.
Rezulin has received a great deal of attention in the press recently. While these results of the studies on the drug are extremely good news for type 2s on insulin, Rezulin should not be seen as a drug that will eliminate the need for insulin therapy. Peters warns, “People need to realize it won’t get everyone off insulin, but many may lower insulin doses and improve control.”
Dr. Sherwin of Yale Medical School and a member of the FDA advisory board adds, “The vast majority (of test subjects) did not come off insulin; only 15 percent came off insulin. It will be used mainly to lower blood sugars and improve control.”
Allen Marcus, MD, from South Orange County Endocrinology, points out that Troglitazone is somewhat similar to Glucophage and Metformin. He suggests that similar drugs for type 2s may be coming in the near future.