Need Information on Namenda

My husband 51 years old is currently on Aricpt, Exelon and Namenda -

Can you tell me what you know and have expereinced o this drug -

He also has had neurological lyme disease - he has had that for 14 years total but only diagnosed wit it in 2002.  He just had a MRI of his brain and there was no change noted since last time.  Any help would be greatly appreciated.

Thank you all for your wisdom and support.

His neurologist put him on all three.

Not good????