Newborns with life-threatening infections are often given these antibiotics, the researchers said.
Investigators focused on aminoglycoside antibiotics, which doctors rely on to treat meningitis, bacteraemia, and respiratory infections in cystic fibrosis patients. These drugs are known to damage the sensory cells in the inner ear that detect sound and motion.
Healthy mice given a low amount of an aminoglycoside developed a small degree of hearing loss. However, mice with an inflammation typical of the infections treated with aminoglycosides in humans had a much greater degree of hearing loss when they were given the antibiotics, the investigators found.
Inflammation from bacterial infections boosts the uptake of aminoglycosides into the inner ear, substantially increasing the risk of hearing loss, the study authors explained.
Their findings were published online July 29 in the journal Science Translational Medicine.
"Currently, it's accepted that the price that some patients have to pay for surviving a life-threatening bacterial infection is the loss of their ability to hear," Peter Steyger, professor of otolaryngology, head and neck surgery at Oregon Health & Science University in Portland, said in a university news release.
"We must swiftly bring to clinics everywhere effective alternatives for treating life-threatening infections that do not sacrifice patients' ability to hear," he added.
Each year, about 80 percent of the 600,000 infants admitted to neonatal intensive care units (NICUs) in the United States receive aminoglycosides, the researchers said. The rate of hearing loss among NICU survivors is 2 to 4 percent, compared with 0.1 to 0.3 percent of full-term infants who have hearing loss due to birth defects, the authors reported.
"When infants lose their hearing, they begin a long and arduous process to learn to listen and speak. This can interfere with their educational trajectory and psychosocial development, all of which can have a dramatic impact on their future employability, income and quality of life," Steyger said.
To protect patients' hearing, doctors should consider other types of antibiotics to treat severe infections. Plus, researchers need to develop new types of aminoglycosides, the study authors suggested.
Image: Ear from Shutterstock