Letter: Questions regarding arginine hydrochloride inhalation.

With regard to the recent study of Dietzsch et al. on the 
use of arginine hydrochloride inhalation in cystic fibrosis patients, I wish 
to point out that these investigators acted irresponsibly in exposing their 
patients for an appreciable period (seven weeks) to a preparation which 
is known to be irritating. I would suggest that the deleterious 
effects seen by Dietzsch et al. are due to their inattention 
to experimental detail and lack of communication with other investigators. - 
Dietzsch et al. give the impression in their article that all 
arginine solution are detrimental to the lung. We wish to point 
out that L-arginine hydrochloride buffered with a sodium solution is irritative 
to the airway of cystic fibrosis patients. However, no comparison studies 
were done with L-arginine buffered with free base. - The fate 
of these children with cystic fibrosis depends on the quality of 
the inhalation treatment. This means if you replace a good mucolytic 
drug with a better one you step by step approach the 
ideal mucolytic solution. We think it to be unethical to use 
other, less effective, drugs or solutions in a control group (e.g., 
saline or distilled water). We did not state that arginine solutions 
are "irritative" or that arginine treatment is "dangerous." The N-acetylcysteine solution, 
which was successfully used before the treatment of our patients, was 
buffered with sodium hydroxide to a pH of 7.0. The quantity 
of sodium which was administered during each inhalation amounts to only 
0.04 mval of sodium so that an injurious pharmacological effect can 
be excluded. Both drugs were well tolerated and had no "deleterious" 
effects. 