Inhaled Insulin as Good as Injections for Diabetics

Medically Reviewed by Gary D. Vogin, MD on May 20, 2001
From the WebMD Archives

Editor's Note: The FDA approved the inhaled insulin drug Exubera in 2006, but in October 2007 the drug company Pfizer said it was halting sales of the drug because of financial reasons.

May 20, 2001 (San Francisco) -- For diabetics, an inhaled powder could make a dramatic difference in quality of life. The experimental substance is a new form of insulin that is rapidly released into the blood through the lungs. This approach won't replace insulin shots completely, but it may reduce them from three or four a day to just one at night.

The powder is administered though a device about the size of a cell phone. The patient cocks the handle that fills the lower chamber with compressed air. Then a blister pack of powdered insulin is inserted and ruptured and the patient inhales the powder and air mix.

"Patients prefer it. Quality of life studies have been done, and patients prefer this hands down," says William Cefalu, MD, associate professor of medicine at the University of Vermont College of Medicine. Cefalu, a diabetes specialist, has been studying the powder in diabetics to see how it compares with standard insulin injections or oral medications.

In three trials conducted over a two-year period, Cefalu compared the safety and effectiveness of the powder in about 200 patients. Each trial lasted three months. He presented his findings Sunday at the international conference of the American Thoracic Society.

"Inhaled insulin appears to work as well as the [skin-injected] insulin on blood sugar control during these three-month studies," says Cefalu.

In type 1 diabetes, the body fails to produce any insulin, the hormone that controls blood sugar, or glucose, levels in the body. Most people with this disease develop it as children. Type 2 diabetes, typically diagnosed in older adults, frequently is associated with obesity and is characterized by insulin resistance -- when the body doesn't respond well to insulin.

It's crucial for diabetics to keep their glucose levels under control to avoid complications like blindness, kidney damage, and amputations. For tight control, patients have to take insulin shots often, an unpleasant requirement.

"Inhaled insulin offers the first real alternative to that because it allows ... multiple treatments of insulin without the injections," says Cefalu, whose studies have been financed by Pfizer, one of the companies developing the inhaled powder.

The studies also show that the powder is actually better than shots for type 2 diabetics who ultimately have to take insulin.

While the powder goes deeply into the lungs, tests found no significant breathing problems, including among people with mild asthma.

"The major breakthrough is the formulation: the fact that this is a dry powder and that once vaporized, particle size is minimal," says Cefalu. Still, the powder wouldn't be recommended for those with pneumonia, and it would need to be evaluated in people with chronic heart disease.

Cefalu declined to say whether the FDA will review the powder soon, although several other pharmaceutical companies are pursuing a similar strategy. The Pfizer drug has been in development since 1996.