I am 69 years old and normally very fit and healthy. I started suffering from very dry mouth while sleeping (the saliva glands appeared to be ok during the daytime. About the same time I was prescribed Toviaz for urinary incontinence. Since then the dry mouth problems has become very severe and even my throat feels like sandpaper after a period of sleep (even if I doze off in the front of the TV!). The area in my mouth behind my upper and lower lips are raw and sore and I currently have a blister on my tongue. Can this be a normal reaction to Toviaz (4mg)?