Aspirin Can Prevent Hearing Loss From Ototoxic Medication
Editor: Researchers at the University of Michigan have discovered that
aspirin can prevent hearing loss that would otherwise occur in users of a
common family of antibiotics. The obvious question is whether aspirin can
prevent hearing loss from other medications. How about from noise exposure?
Around the world, inexpensive antibiotics known as aminoglycosides have
been used for the past 60 years in the battles against acute infections and
tuberculosis, as antibacterial prophylaxis in cystic fibrosis and other
patients, and in and other conditions. But for all of the good they do, the
drugs also have been widely linked to irreversible hearing loss.
Now, researchers at the University of Michigan's Kresge Hearing Research
Institute and their Chinese colleagues, working under the leadership of
Jochen Schacht, Ph.D., and Su-Hua Sha, M.D., have found that the hearing
loss can be prevented in many people with the use of another inexpensive,
widely available medication: aspirin. The results appear in the April 27
issue of The New England Journal of Medicine.
The researchers studied 195 patients in China who received 80 to 160
milligrams of gentamicin (a type of aminoglycoside) intravenously twice
daily, typically for five to seven days. Of those, 89 patients were given
aspirin along with the antibiotic, and 106 were given placebos along with
the antibiotic. The results were dramatic: The incidence of hearing loss in
the group that was given placebos was 13 percent, while in the aspirin group
it was just 3 percent, or 75 percent lower.
"We would like to see the word get around to the medical community around
the world that you can take some precautions to minimize the risk to your
patients. Aspirin is available everywhere, and it's cheap," says senior
author Schacht, professor of biological chemistry in otolaryngology at the
University of Michigan Medical School and director of the U-M Health
System's Kresge Hearing Research Institute. Gentamicin is not commonly used
in the United States.
He notes that this research builds on earlier U-M studies that showed
promise in combating drug-induced hearing loss in the laboratory.
"Previously we found that such a treatment works well in mice, but I am very
excited that this worked so well in humans," says Schacht. "Translating
animal studies into clinical practice is not an easy thing to do. We were
fortunate that our extrapolation from mice to men and women worked in the
The research is exciting, says lead author Sha, because hearing loss
caused by these antibiotics is so prevalent. The incidence of aminoglycoside-induced
hearing loss averages 8 percent but the numbers may be higher in developing
countries, she notes, where aminoglycosides are frequently the only
affordable antibiotics and are sold over the counter. No therapy currently
exists to prevent ototoxicity.
This research began in 1999 with a collaboration with Chinese hospitals.
Working with Schacht, Sha - associate laboratory director of U-M's Kresge
Hearing Research Institute's Biochemistry Laboratory - got in touch with her
colleagues in China. The two traveled to China and presented their ideas,
and ultimately began a partnership with the Fourth Military Medical
University in Xi'an, China. The third author on the paper, Jian-Hua Qiu,
M.D., represents the colleagues of the Fourth Military Medical University.
After receiving approvals from institutional review boards at U-M and the
Fourth Military Medical University, the otolaryngology department in Xi'an
conducted the prospective, randomized, double-blind trial at Xijing Hospital
and Airforce Chengdu Hospital from 1999 to 2003. All of the participants
were ages 18 to 65, and were inpatients who were scheduled for treatment
with gentamicin. Hearing damage, or ototoxicity, was defined as a shift from
a person's baseline hearing by at least 15 decibels at both the 6 and 8 kHz
frequencies, which are the first affected by the drugs. The effectiveness of
the gentamicin as an antibiotic did not lessen when it was paired with
Schacht notes that even though gentamicin has been linked widely with
hearing loss, and its use has been declining in industrial countries, it is
not practical to think that it will be replaced in the near future by other
antibiotics because it has specific applications and is so inexpensive and
available, especially in poor countries. While aspirin shows promise, and he
hopes that health care providers pair it with gentamicin, he also notes it
is not yet the perfect solution because of the potential side effects of
aspirin, including gastric bleeding. And he notes that this is an off-label
use of aspirin, which may inhibit some practitioners from giving it to
patients in such instances.
He hopes that further studies will lead to the development of new and
safer antibiotics, or another drug that can be paired with gentamicin that
has fewer side effects than aspirin. He and Sha are exploring partnerships
with other countries to conduct future research.