Aminoglycosides are a class of antibiotics that are given to people with cancer and after radiation therapy. The majority of people that receive the massive amount of aminoglycosides become deaf. Dr. Anthony Ricci, professor of otolaryngology-head and neck surgery at Stanford University, and Dr. Alan Cheng, associate professor of otolaryngology-head and neck surgery at Stanford, have developed a new modification of aminoglycosides that does not cause deafness in mice according to their report in the edition of the Journal of Clinical Investigation.
The researches first discovered that the antibiotics taken in huge doses necessary in cancer treatment kill the sensory hair cells of the inner ear. The sensory hair cells of the inner ear are never regenerated so deafness is the result. The next step was identification of the part of the aminoglycoside compounds that were toxic to the hair cells of the inner ear. The researchers developed nine variants of the antibiotic. Three of the variants proved to be successful in eliminating E. coli bacteria without causing hearing loss. The process took seven years.
One might ask why this type of drug is ever used in the first place. The choice in the treatment of cancer in very young people and the treatment of bacterial disease in premature children is to let the child die or use an antibiotic that could make the child deaf 60 percent of the time. The drugs also have advantages for use in underdeveloped regions where refrigeration is not possible. Another advantage of the drug is the low cost. The new development means this type of antibiotic can still be used without causing deafness in children.
