Hearing loss-linked drug made safer

A safer version of a potent antibiotic for serious infections that often causes hearing loss has been developed by scientists.

An estimated 20 per cent to 60 per cent of all patients treated with aminoglycoside antibiotics - including newborn babies - experience partial or complete deafness, which is irreversible.

Now researchers have produced a modified version of one of the drugs that works effectively in mice without causing hearing loss or kidney damage, another common side effect.

Aminoglycosides, which include streptomycin and gentamicin, are widely used to treat serious infections and sepsis, a deadly condition marked by the immune system going into overdrive.

They are also given to infants with life-threatening infections.

But the drugs have serious side effects, including hearing loss due to the destruction of inner ear hair cells that help turn sound vibrations into nerve signals.

Professor Anthony Ricci, from Stanford University in the US, said their goal is to replace the existing aminoglycosides with ones that aren't toxic.

"If we can eventually prevent people from going deaf from taking these antibiotics, in my mind, we will have been successful," he said.

Having successfully completed tests in mice, the team hopes to move onto patient trials "as soon as possible".

The scientists took four years to produce five grams of the newly patented antibiotic N1MS, which is derived from the aminoglycoside drug sisomicin.

Results published online in the Journal of Clinical Investigation showed that N1MS cured urinary tract infection in mice as effectively as sisomicin, without resulting in deafness.