Antibiotics Can Damage Hearing, Scientist Says

              2-A Tuesday, Aug. 8, 1972
LSUS Professor
Antibiotics Can Damage
Hearing, Scientist Says
By Margaret Martin
Of The Times Staff
A study by a local scientist
has shed light on deafness
caused by certain antibiotics.
The study is significant because
it may lead to development of
safer antibiotics.
Dr. Don R. Brown, associate
professor in the Department of
Pharmacology and therapeutics
at the LSU School of Medicine
here, presented a paper detail-ing
his findings at the 5th
International Congress on Phar-macology
held recently in San
Francisco, Calif.
He said research on cats
indicates that ototoxio antibiot-ics
(antibiotics w h i c h cause
damage to hearing) "may be
blocking the normal function of
certain protective nerves lead-ing
from the brain to the inner
ear, thereby causing damage to
;he inner ear."
The specific antibiotic under
nvestigation is neomycin, stud-ied
because "it is the most
ototoxic of this group of anti-biotics."
Brown explained that "it is so
toxic to the ear that it is no
longer given by injection; it is
used in ointment form to apply
to minor skin wounds . . . since
very little gets into the blood-stream
and it is usually not
o t o t o x i c when used in this
form." (Antibiotics. Brown ex-nlained
are "usually derived
from a mold of some kind,
which is given to c o m b a t
infection caused by bacteria.")
In an outline of the paper,
Brown explained that the nerves
which conduct nervous impulses
from, the brain back to the inner
ear are called cochlear effe-rents.
Thus, the brain affects
way in which sound waves are
converted by the inner ear "and
also appears to act to prevent
the cells in the cochlear (inner
ear) from becoming overexcited
by sound."
Explaining f u r t h e r , Brown
said that the efferent cochlear
serve to reduce the amount of
sound to the brain.
The c o d i n g effect, of the
nerves also affects sound dis-crimination
and may "more or
less protect cells from over
stimulation," Brown explained
in an interview.
But when the drug blocks this
protective function, cells are
destroyed.
The end result of Brown's
research is the possible develop-ment
of antibiotics which could
be used effectively to treat
infections, "but which have less
or no associated ototoxicity."
Brown said in the outline that
research centered around not
only neomycin, but other chemi-cally
related antibiotics.
Although the group of antibiot-ics
are "valuable therapeutic,
agents . . . one of their major;
liabilities . . . is their ototoxici-ty,"
Brown said.
He pointed out that several of
the chemically related antibiot-ics
are less ototoxic and are
more useful clinically.
"One member of this group,
streptomycin, is a v a l u a b l e
agent in the t r e a t m e n t of
tuberculosis and another mem-ber,
kanamycin is used exten-sively
in the t r e a t m e n t of
c e r t a i n other infectious dis-eases.
Both of these drugs do
carry a risk of hearing damage
associated with their use, how-ever,
and this l i m i t s their
usefulness," Brown said.