How does inhaled insulin work
There has been lots of research in the field of insulin
administration. To keep blood sugar under control insulin is
injected. P atients would prefer inhaled insulin to injected
insulin especially, when sometimes you have to take up to 6
injections daily. The different targets tried for insulin
delivery are through the upper airways i.e. the mouth, the nose
, the skin and even as suppositories. Oral delivery is not
possible due to the acidity of the stomach and the digestive
enzymes of the intestines which prevent the insulin molecules to
absorb into the blood. Inhaled insulin can reduce or eliminate
the daily insulin injections.
There are several systems in developmental phase by different
pharmaceutical firms with products like Aerodose R , AERxTM
Diabetes Management System, Qdose R and Exubera R .
An advisory panel to the U.S. Food and Drug Administration on
September 8 th 2005 recommended approval of Exubera an inhaled
insulin for adults with type 1 or type 2 diabetes. It is
predicted that Pfizer would launch Exubera in late 2006.Exubera
is produced by Sanofi-Aventis and Nektar Therapeutics, a
California biotechnology firm (formerly Inhale Therapeutic
Systems, Inc.) in partnership with Pfizer.
Other inhalable insulins still on human testing are by
Indianapolis-based Lilly and Alkermes Inc., and another is by
the Danish firm Novo Nordisk and Aradigm. The Lilly-Alkermes
inhaler is small enough to fit in the palm of the hand and is
breath-activated, but Exubera, a larger device and it relies on
compressed air to operate. The Lilly-Alkermes inhaler is
expected to reach the market only by 2008.
How does inhaled insulin work?
The delivery of the Exubera is designed in such a way that this
should be small enough to get into the lungs and not large
enough to be breathed out. Exubera is a rapid-acting, fine
dry-powder insulin. The blister packs are loaded into the
inhaler device and a trigger is squeezed to disperse the insulin
powder into the compartment above. When this is inhaled through
the mouth the finely powdered air reaches directly into the
lungs. Insulin passes through the alveolar wall found in the
lung and enters into the blood circulation. Breathing once or
twice would be sufficient. The content in the blister pack is 20
% insulin and 80% is not revealed. The insulin is reported to be
stable for 6 to 24 months at room temperature. Proper training
will also be given to people on how to use the inhaler properly.
I nhaled insulin enters the bloodstream more rapidly than by
subcutaneous injection.
Blood sugar control was equivalent when compared to injected
regular and inhaled regular insulin. There are some concerns
about the long term effects of chronic inhalation of a growth
protein into the lungs. Some experts are also worried about
people exposed to second hand smoke or lung disease like asthma
or emphysema especially since there have been minor reductions
in breathing efficiency in some patients and some patients
reported coughing.
This inhaler is also effective during cold and upper respiratory
infections but may not be that effective during pneumonia.
Smokers will be excluded from taking the drug because the cells
in the lungs will be already damaged due to smoking t heir blood
sugar could fall dangerously low with Exubera because they
absorb much more inhaled insulin in their lungs than nonsmokers.
Delaying insulin treatment can contribute to higher blood sugar
levels, which can lead to complications such as nerve damage,
cardiovascular problems, vision loss and kidney disease.