Researchers from Oregon Health & Science University have found that people who have a dangerous bacterial infection are at a higher risk of hearing loss due to using life-saving antibiotics. The inflammation that occurs as a result of the bacterial infections are what increases the susceptibility to the hearing impairment and hearing loss by increasing the uptake of aminoglycoside antibiotics into the inner parts of the ear.
The new findings were just published in Science Translational Medicine, and the researchers were investigating why so many people get permanent hearing loss from the use of these antibiotics. Some patients right now have to accept the fact that they will lose their hearing as a result of getting the life-saving antibiotics, but researchers believe that there should be effective alternatives for treating the life-threatening infections that do not require a patient to lose their hearing. Peter S. Steyger, a professor of otolaryngology, head and heck surgery, at Oregon Hearing Research Center, Oregon Health & Science University School of Medicine had something to say about the importance of finding a new cure as the lead author of the study. Steyger said that most of the patients who are given the aminoglycosides are babies who have life-threatening infections. Then, the infant will lose their hearing, which results in an long journey of learning to speak and hear, and it really is a burden on society. The loss of hearing interferes with schooling and psychosocial development, and that all impacts their future employability and quality of life, not to mention income potential.
The aminoglycosides and antimicrobials are indispensable when it comes to treating the life-threatening bacterial infections, but they are also very toxic to the ears. The physicians rely on the aminoglycosides to treat meningitis, bactermia, and respiratory infections in patients who have cystic fibrosis. The aminoglycosides end up killing off the sensory cells in the inner ear that help detect motion and sound. The group that is at a particular risk is infants who are in the neonatal intensive care unit. About 80 percent of the 600,000 admissions into the neonatal intensive care unit every year are getting aminoglycosides, and the rate of hearing loss is between 2 and 4 percent, compared to the .1 to .3 percent of the full-term birth babies who have congenital causes of hearing loss.
Steyger and his colleagues gave healthy mice a low amount of aminoglycosides, and they experienced a small degree of hearing loss. If the mice had the inflammation that was typical of the infections treated with aminoglycoside in humans, the mice then experienced a vastly greater degree of hearing loss. This particular study helps provide some insight into how doctors can improve the standard of care guidelines for the patients who are receiving aminoglycosides. In order to help shield the hearing of the patients, the researchers called for the development of targeted aminoglycosides and then urged the clinicians to choose a more targeted non-ototoxic antibiotics or even anti-infective drugs that could treat the patients that have severe infections. It is because aminoglycosides are so available and are also cheap that they are most commonly used around the world. The clinical use of aminoglycosides are limited to just the known risk of acute kidney poisoning and permenant hearing loss, but these drugs are needed for those who have life-threatening infections.
If the doctors do not use these medications immediately when a problem is identified, then there is a possibility that the person, especially if it is a newborn, will die. In terms of what is better, the doctor looks at saving the life of the person as more important than the potentially dangerous side effects of the medications, because there are things that can be done to help regain hearing to some extent, including things like cochlear implants. The issue is though that these medications are becoming too commonly used, which means the incidence of permanent hearing loss is increasing, so these medications should only be used when absolutely needed, and other drugs need to be developed that could save the life of the person without having all of the troubling side effects, and this is why a more targeted drug would be appropriate.