Irenea8, About a year in to being on Toby, I started to lose my voice. I pushed through for another six months but when my hearing was impacted, I called it quits. I started Colistin and have been on it for over two years. I find it easy to tolerate. I have not noticed any negative side effects. As per NJH recommendation, I use it two weeks on/off. My last sputum sample showed few pseudomonas, which is a first! Before starting inhaled antibiotics, I was on at least five PICC lines, so I am thankful this current therapy is working. I hope you find what works for you!