If you're looking at a new use for a drug that's currently approved in
the U.S. as an injectable, you'd be well advised to consult both a
physician and a compounding pharmacist as regards that specific
product and application. I did find a number of references to both
early evaluations of tobramycin by inhalation and currently available
products. It appears that the currently available jet nebulizer
product was originally a reformulation of an injectable product.
It is possible that the nebulized product would have to be milled for
particular particle sizes to enhance its chance of reaching deeper
into the lungs
(and working with a particular nebulizer) and may have additional
adjuvants to improve flow and anti-clumping properties as compared to
the injectable.
An early abstract regarding the use of tobramycin by inhalation in CF
patients may be found at:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11555564&dopt=Abstract
I found the following comment in the March/April 1998 "FDA Consumer",
a publication of the U.S. Food and Drug Administration at
http://www.fda.gov/fdac/departs/1998/298_upd.html
"Tobi (tobramycin for inhalation) is the first inhaled antibiotic for
people with cystic fibrosis, an inherited condition that can lead to
diminished lung function and chronic lung infections. Tobi suppresses
Pseudomonas aeruginosa bacteria, a potentially dangerous microorganism
that affects the lungs or respiratory system of most people with
cystic fibrosis.
A reformulation of the injectable form of tobramycin, which FDA
approved in 1975, Tobi helped improve lung function and reduce
bacteria in sputum in clinical trials. Side effects included voice
alteration and ringing in the ears.
Manufacturer: PathoGenesis Corp., of Seattle."
If you're specifically interested in current product information on a
tobramycin product for administration by inhalation, I would direct
you to:
http://www.abouttobi.com/
That's the site for product information on "Tobi" (now Chiron's) brand
of tobramycin inhalation solution for treatment of Pseudomonas
Aeruginosa infections in cystic fibrosis patients.
Based on this article at http://www.pharmaquality.com/Formulation.htm
it appears that Chiron is now working with another company on other
formulations of inhaled tobramycin for localized infections.
"Localized Treatment of Lung Diseases?Infection remains the leading
cause of death worldwide; pneumonia and other lung infections account
for a large proportion of those deaths. Such diseases respond well
when treated locally with pulmonary-administered therapeutics. For
example, as little as 1/50 of a dose of an orally administered drug
may actually reach the lungs compared to the same drug taken by
inhalation. A drug delivered via the pulmonary route goes directly to
the infected lungs, offering the potential for faster, more efficient
therapy, reduced risk of drug resistance and fewer side effects.
Similar treatment benefits may be experienced with pulmonary drugs
directed toward local treatment of other lung diseases such as lung
cancer, emphysema and severe asthma. Chiron Corp. of Emeryville, CA is
collaborating with Nektar to develop a dry-powder inhaled version of
the Chiron TOBI® tobramycin product and other inhaled antibiotics for
locally treating lung infections."
(An aside: I hadn't realized that P.Aeruginosa was an opportunistic
infection in CF cases. Every hot tub owner who is conscientious about
their water chemistry is aware of that particular microbe, as it is
fairly tough to kill due to its ability to secrete protective biofilms
that can protect it from disinfecting agents.) |
