49
serum chemistries, their cardiovascular responses, their neurologi-
cal signs, and their ophthamological changes, if there were any.
Following the toxicity studies, which took 18 weeks, we conclud-
ed that there were no significant changes in the serum chemistry
at any time during the observation period. These changes, of
course, were compared to a control series of animals.
There were no changes in the urine, and there were no neuro-
logical changes. There were no changes in the cardiovascular re-
sponses. There were no ocular changes. We were curious to see if
there might have been some changes in the refraction or translu-
cency of the lens, since some years previously this had been report-
ed to have been a problem in rabbits.
One of the ophthamologists reviewed these animals before and
after DMSO, not knowing which animals had received the drug,
and it was concluded that there were no changes at all in the eyes
of these animals.
Then following the experiments, the animals were autopsied and
the tissues examined histologically. No pathologic changes in the
histology were found.
So, our conclusion then is that DMSO, at least as far as these
events were concerned, is an effective and relatively nontoxic drug
as used intravenously.
Our results in spinal cord injury, brain trauma, and stroke have
been confirmed by at least three different groups of investigators
in other parts of the country for each project.
We feel that DMSO is a highly effective drug in central nervous
system injuries that we have mentioned, and it may open possibili-
ties to other neurological disorders that affect brain swelling.
For example, in children there is a syndrome-Reye's-where
there occurs an increased intracranial pressure, and often surgery
or drug treatments are not very effective. So, it does open the door
to other neurological disorders.
I feel that at this point, and with all the accumulated evidence at
hand, that perhaps the time has come to approve use of DMSO
because it will make it easier for clinicians to use it for their
studies.
Right now, if the clinician wants to use it in a clinical study, he
has to go through NDA and FDA approval, and it takes a long time
to get it and there is a lot of paperwork.
Some clinicians are put off by all this paperwork, and they will
not do a clinical study under those conditions. But if the drug is
approved, I believe that it will enhance our understanding of how
it is working and may provide clues to even better drugs than that.
The CHAIRMAN. Doctor, why, in your opinion, has FDA turned
down the approval of this substance and delayed so long its approv-
al of it?
Dr. DE LA TORRE. I don't know. We presented our data to them
and the experimental evidence was there for anyone to review.
And of course they make their decision as to whether or not the
drug should be approved.
The CHAIRMAN. Did you have any adverse reaction from any of
the animals you used it upon?
Dr. DE LA TORRE. No. There is no significant toxicity involved in
this drug, even with high intravenous doses. I believe this has been
