DIABETES DRUG GAINS APPROVAL.

Byline: Warren E. Leary The New York Times

The Food and Drug Administration approved a diabetes drug Thursday that is the first in a new class of medications intended to attack an underlying cause of the disease.

The prescription drug, to be marketed by the Parke-Davis division of Warner-Lambert Co. under the name Rezulin, offers some diabetics the possibility of reducing or ending their dependence on daily insulin injections, the FDA said.

The manufacturer said Rezulin, known chemically as troglitazone, would be available in pharmacies by the end of March. The pricing of the drug, available in pill form, has not been determined, a spokesman for the company said.

Rezulin is the first of a class of drugs called insulin sensitizers, intended to help diabetics make better use of insulin produced by their bodies or taken through injections. The drug works by somehow resensitizing tissue in the body to insulin, a hormone produced by the pancreas that converts blood sugar, or glucose, into energy.

An FDA advisory panel unanimously recommended last month that troglitazone be approved for use with adult onset, or Type II, diabetes, a type that does not respond well to conventional treatment. The agency said the approval, the first for the drug worldwide, was granted within six months after its application had been submitted.

The president of the American Diabetes Association, Dr. Philip Cryer, said that the approval was exciting, but that there still should be caution in using it.

``This is scientifically interesting, because this drug represents a new class of drugs,'' Cryer, director of the endocrinology division at Washington University in St. Louis, said in a telephone interview. ``Because it has a totally different mechanism of action than other diabetes drugs, there is a possibility in the future that it could be used by itself as primary treatment, instead of in conjunction with insulin, as now recommended.''

Cryer said people who tried the new drug should work closely with their doctors in monitoring blood sugar levels to see how much they could reduce their insulin intake with the treatment. ``Under no circumstances,'' he said, ``should patients reduce or stop their insulin by themselves.''

About 16 million Americans have diabetes, experts said, with one million afflicted with the Type I variety that usually emerges in childhood. Type I diabetes, which is characterized by the body's failing to produce enough insulin, is treated by closely monitoring blood sugar and taking daily insulin injections.

Type II diabetes, also known as the noninsulin-dependent type, usually develops in adulthood. Although the body produces enough insulin, tissues develop a resistance to its actions, and sugar levels rise above normal. Uncontrolled glucose levels can result in blindness, organ damage and other complications.

In most cases, Type II diabetes, which is worsened by obesity, can be controlled through weight loss, dietary changes and regular exercise. If that fails, as happens with 10 percent to 20 percent of patients, diabetes is treated with oral drugs that stimulate insulin production or lower glucose levels. As a last resort, patients turn to insulin injections, experts said.

The FDA said in two clinical trials involving more than 500 patients, troglitazone significantly improved the subjects' ability to manage their disease by making better use of insulin that was made naturally in their bodies or taken through injection. In the tests, 15 percent of the patients who used troglitazone no longer required insulin injections to manage their sugar levels, the company said.

Dr. Solomon Sobel, director of the FDA division that oversees diabetes drugs, said adverse effects of troglitazone appeared to be rare and relatively mild, including infection, pain and headache. But, he said in an interview, animal studies suggest that the drug should be prescribed with caution for patients with advanced heart failure or liver disease.