June 10, 2000 (San Antonio) -- If you're a diabetic and dream of a needle-free future -- keep on dreaming ... for a while, at least. That's the word from a group of experts who spoke Saturday at the American Diabetes Association's (ADA's) annual meeting. Although several companies have inhaled insulin products waiting in the wings for government approval, the inhalers (which are like the ones used by people with asthma) come in only a few sizes, and some experts are concerned about the long-term effects on the lungs.
Because a typical dose of inhaled insulin is about 10 times as large as an injected dose, it may not be possible to achieve the ultra-tight glucose control required in type 1 diabetes. For this reason, Stephen C. Duck, MD, who co-chaired the ADA session, tells WebMD that inhaled insulin should be seen first and foremost as a therapy for type 2 therapy.
"Cautious excitement is in order," he says, "but this may be wonderful for people with type 2 disease," says Duck, an associate professor of pediatrics at Northwestern University Medical School in Chicago.
Because the lungs were not intended as a way to get insulin into the body, investigators will want to carefully examine the long-term effects of using them that way. This will be particularly important now that a long-acting inhaled insulin is being studied, Duck says. Long-acting insulin is used to boost the effects of standard, shorter-acting insulin between doses.
The long-acting formula has only been looked at in animals, says Rick Batycky, PhD. He is a researcher for Advanced Inhalation Research, the company that makes the drug. His research team found that the slow-acting inhaled insulin worked in rats for about 8 hours after they inhaled it. They soon plan to study long-acting inhaled insulin in people, he says.
Short-acting formulas of inhaled insulin are farther along in development, and some are getting close to government approval. One is under development by Profil Research, says Tim Heise, MD, general manager at Profil. In a small trial to make sure the drug is safe, he says, 18 healthy volunteers inhaled the drug, which then reached its peak in about 30 minutes This is the same time it takes injectable short-acting insulin to work.
"Inhaled insulin is only available in three doses at this point," Heise tells WebMD. "Inhaled formulations are still at the beginning stages of development. It will be several years before we can even discuss the notion of injectable insulin as a thing of the past." For this reason, he says, people with diabetes need to continue to be patient.
Every new development has disadvantages, and many aspects of inhaled insulin are still unknown. For example, would a patient who quits smoking cigarettes need a new dose? If a patient catches a cold, would he or she need to take a higher dose of insulin?
Pfizer and Aventis are partners with Profil in the development of short-acting inhaled insulin. Duck has been an investigator for Pfizer-sponsored trials of inhaled insulin in children. He has no other financial relationship with Pfizer or any other drug company.