My 89 Year Old Father Has Parkinson's Disease Among Other

My 89 year old father has Parkinson's disease among other things. 2weeks ago his Dr prescribed Gabapentin. Since starting the drug he has fallen almost every day and had never fallen prior. He is in the hospital for breathing issues, low kidney function. Doing some on line research I see that unsteadiness is a side effect. Should I bring this up to the Dr ?