Inhaled Insulin Effective For Diabetes

But Study Raises Concerns Over Long-Term Lung Impact

(WebMD)  But Ceglia's analysis also showed high levels of patient satisfaction with inhaled insulin therapy.

She suggested this may be related to the "novelty of the new delivery method" and cautioned it remains to be seen if patients will be as enthusiastic and adherent to inhaled insulin therapy over the long term.

"It's exciting that this new therapy is out," Ceglia says. "It's been in development for a long time. We'll just have to wait and see how it goes."

Safety Concerns

Ceglia's analysis doesn't raise any immediate alarm. "Certainly there was nothing in the first two years that was frightening," she says.

But that doesn't mean there are no concerns. Leading the list is inhaled insulin's long-term effect on lung function.

Even in the short term, patients on inhaled insulin are more than three times as likely as those on injected insulin to develop a dry cough. "This appears to be an immediate reaction to the inhlation and doesn't seem to progress over time," Ceglia says.

Lung Damage?

More worrisome, patients on inhaled insulin were more likely than those on injected insulin to experience a mild decrease in lung function. The mild decrease in lung function happened early in the study and did not worsen over two years.

Another potential problem is severe hypoglycemic reactions, which were shown to be as likely with inhaled insulin as with injected insulin. That could be because inhaled insulin devices don't yet allow for finer dosing adjustments that may be necessary to avoid hypoglycemia, according to the study.

"Based on the trials we analyzed, we can't make any definitive conclusions about the safety of inhaled insulin," Ceglia says. "Like any new drug, however, inhaled insulin is going to have to be tested further and assessed for its long-term efficacy and safety."

Recommendations

Because of long-term safety concerns, Ceglia's team recommends that inhaled insulin be reserved for patients without pulmonary problems, who oppose injections and would otherwise not receive appropriate and timely therapy for their diabetes.

When contacted by WebMD, Pfizer officials said they were reviewing Ceglia's analysis. They issued a statement reiterating their belief that Exubera "represents a major advance in the treatment of diabetes.

"In clinical trials, Exubera was found to be as effective as short-acting subcutaneous insulin injections, and to significantly improve blood sugar control when added to oral medications," the statement reads. "This is reflected in the Exubera product labeling in the United States and European Union."

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SOURCES: Lisa Ceglia, MD, division of endocrinology, diabetes, and metabolism, Tufts-New England Medical Center, Boston. Larry Deeb, MD, president of medicine and science, American Diabetes Association, Alexandria, Va. Pfizer statement from Rebecca Hamm, U.S. Pharmaceuticals Public Relations, Pfizer, New York. Ceglia, L. Annals of Internal Medicine, November 2006; vol 145: pp 665-675.