Aminoglycosides are a class of antibiotics that save countless lives every year. Unfortunately, the medications come with a significant risk of partial or complete hearing loss in patients. The good news is that scientific researchers have succeeded in modifying these drugs in a way they believe will allow aminoglycosides to not only save patients’ lives but also preserve their hearing.

Aminoglycosides are a group of bacterial antibiotics that are commonly used to treat conditions such as pneumonia and septicemia, as well as complicated infections of the skin, bone, and urinary tract. These drugs are often used to treat infections in cancer patients, who are likely to experience weakened immune systems due to intensive radiation treatment. Aminoglycosides save the lives of many who use it, but also cause some degree of hearing loss in between 20 to 60 percent of all users by causing damage to the inner ear, according to a recent press release. Kidney damage is another risk often associated with the drugs.

Part of aminoglycosides’ success is the fact that they are relatively cheap and require little maintenance. This allows them to be used in areas with fewer medical resources.

In a study published today in the Journal of Clinical Investigation, researchers at Stanford University School of Medicine have created a modified version of aminoglycosides that continues to exhibit the same life-saving properties without the increased risk for deafness and other common side effects. Although the modified drug has thus far only been tested on mice, the researchers are confident that it will yield similar results on human subjects.

“If we can eventually prevent people from going deaf from taking these antibiotics, in my mind, we will have been successful," said Anthony Ricci, one of the senior authors of the study, in a press release. "Our goal is to replace the existing aminoglycosides with ones that aren't toxic."

The drug causes deafness by killing the hair cells in the ear which detect sound. Modifying the drug so that it does not damge the hair cells in the ear—while still remaining effective— wasn't simple, and many minor adjustments in the drugs makeup were found to compromise its life saving abilities. "So many approaches have failed," Ricci explained in thepress release. "The main problem has been that if you succeeded in stopping the drug from killing hair cells, then you also stopped its antimicrobial effect. The drug just doesn't work anymore."

Through careful targeting of specific areas of the drug the team was able to manipulate molecules not involved in the infection fighting ability of the medication. “This allowed us to reduce toxicity to the ear while retaining antimicrobial action," concluded Ricci.

In an email to Medical Daily, Ricci explained that the next step is to conduct animal studies in nonrodents and undergo toxicity testing by the Food and Drug Administration. Then, the antibiotics can undergo human clinical trials. “The plan is to have lead compound to trials in about a year, but right now we need funding to continue,” added Ricci.