Cough for 3days of a 3 yr old child.

My daughter has cough the pedia advised for salbutamol nebule three times a day. But one of my relatives said it causes thinning of the lung tissue itself as told by one of her doctors. I don't know if she fully understood the explanation to her since she's not in the medical profession but I am. I have done tons of research of it explaining about salbutamol's causes but there's none. I may have believe her if it's corticosteroid inhalations she's pertaining to. Since even then it causes thinning of skin when applied topical. You may then deduce to the fact that it can affect thinning of lung tissues too. But it's merely salbutamol we're talking about. Should i be worried about this? My daughter has turned 3 yrs old this month. I have not asked her pedia yet though her opinion bothers me little bit. Is there someone who could give a research based explanation to me before i'll succumb to her own idea about salbutamol? She's very adamant that it gets into my nerves.thanks a lot