Washington: Researchers have developed a modified version of an aminoglycoside, the most commonly used class of antibiotics worldwide, that may eliminate the risk of hearing loss.
Treatment with aminoglycosides is often a lifesaving necessity. But an estimated 20-60 percent of all patients who receive these antibiotics suffer partial or complete hearing loss.
Scientists at the Stanford University School of Medicine have conducted a study where the new version of antibiotic worked effectively in mice without the risk of causing deafness or kidney damage, another common side effect.
The researchers hope to test versions of the modified antibiotic in humans as soon as possible.
It took the scientists 4 years of research to produce 5 grams of the newly patented antibiotic, N1MS, which is derived from sisomicin, a type of aminoglycoside.
Anthony Ricci, PhD, said that N1MS cured urinary tract infection in mice just as well as sisomcicin, but did not cause deafness. The study presents a promising new approach to generating a new class of novel, nontoxic antibiotics.
Because aminoglycosides cause deafness by killing these nonregenerating hair cells, Ricci postulated, why not simply make the drug molecules unable to enter the cells' channels?
The goal, Ricci said, was to keep the antibacterial properties of the drug intact while preventing it from entering the inner-ear cell's ion channels. He and his fellow researchers used data from structural biologists at Stanford who better understood how the antibiotics fought off infection.
Ricci targeted sites on the drug molecule that were not involved in the antimicrobial activity that killed off infection. This allowed them to reduce toxicity to the ear while retaining antimicrobial action.
The study is published online in the Journal of Clinical Investigation.