New Methods May Mean Fewer Insulin Shots for Diabetics
WebMD News Archive
The spray device has been tested in about 300 patients in the U.S. and other
countries. In Canada, long-term trials -- the final step before drug approval
-- recently began. The U.S. equivalent of those studies is expected to begin
within the next two or three months, Krosnick says.
But a few hurdles must be cleared before the devices are approved for use.
One potential problem is that, unlike injections that are precisely measured,
inhaled doses may not be exactly the same each time people take them. Another
concern is that taking particles deep into the lungs could cause breathing
problems in some people, or lead to unhealthy changes in lung cells.
Skyler says some patients have been on the inhaled insulin for at least
three years with no apparent lung problems. He adds that animal studies do not
support the idea that insulin causes unhealthy cell changes in the lung. In
human studies, testing of lung function has shown no changes among insulin
inhalers, according to Inhale Therapeutic Systems, one of several companies
that are developing inhaled insulin products.
Although an insulin pill might be easiest of all to use, insulin is
currently only taken by injection. That's because it is a protein, which can be
broken down in the stomach, like food, before it starts to work on blood sugar.
Insulin injections get the drug into the bloodstream fast, and are typically
taken before eating and before going to bed. The challenge for researchers has
been to convert the insulin into a form that can be absorbed in a way that
bypasses the stomach's acids.
Christopher Price tells WebMD that, unlike others who have tried to make
pills that protect insulin molecules from degradation by stomach acid, his
company, Protein Delivery Inc., of Research Triangle Park, N.C., is taking a
different approach. By modifying the insulin's structure with substances that
protect it from degradation, then encapsulating the resulting gel-like
substance, researchers have been able to get insulin to the liver intact.
"This is important, not only because it mimics the pathway that insulin
takes in a normal person, but it is the one thing that's missing from any other
method of insulin delivery. They all go into the [bloodstream] first, and very
little insulin, in a very delayed fashion, actually gets to the liver,"
The pill is being tested at Georgetown Medical Center in Washington. Price
says a viable version is not expected before 2005. Like the spray products, it
is meant to be used before meals as a supplement to long-acting insulin.
Another promising advance involves an alternative to insulin itself.
Investigators at Merck Research Laboratory are working with a compound derived
from the leaf of an obscure fungus found in the Congo. In studies in animals,
the fungus was found to mimic the effects of insulin.