Lifesaving medicines could compromise hearing

As March is TB month and people in the medical profession gear up to create awareness of this common and often deadly infectious disease, it is of paramount importance to inform also patients of the risks, as a majority of drugs administered in the treatment of TB are ototoxic and include Isoniazid, Rifampin, Streptomycin and Para-amino Salicylic Acid among others.

Lezanie Bakker, GM of Oticon, a leading hearing aid manufacturer, warns about the pitfalls of ototoxic medication. "I am sure we have all received prescribed medication at some stage in our lives and usually all the jars, boxes and bottles have little information leaflets that accompany them. How many of us actually read it? Does your doctor or pharmacist discuss some of the side effects that the medication may have on you? Do you know what an ototoxic drug is?

"Ototoxicity is damage that is done to a person's hearing by means of a toxin. The toxin is often introduced to the system through medication, which affects the cochlea or auditory nerve and sometimes even the vestibular system. The damage can range from being temporary to permanent and can cause ringing in the ears (tinnitus) or a lack of balance. What makes the whole process such a grey area is the fact that most ototoxic medication is necessary to save the patient's life which therefore creates a double edged sword whichever way you look at it."

Ototoxic drugs include some antibiotics, loop diuretics, medication for renal failure and platinum-based chemotherapy agents such as Cisplatin to name a few.

"Typically, ototoxic drugs begin their damage at the highest frequency at which the human ear can hear and then work their way down the frequency spectrum. It means that the hearing loss becomes more pronounced as time passes. The patient might not even be aware of the damage as it occurs.

"The best approach is to be aware of the risk that the medication has on your hearing by talking to your doctor. One should continuously undergo hearing tests before and whilst taking ototoxic medication. In some cases the hearing loss can be addressed by means of intervention in the form of hearing aids or even a cochlear implant. It is however crucial to note that nerve damage cannot be remedied and it is something that the patient will have to adjust to if such damage occurs," concludes Bakker.