I've just a quick moment having just read your post. My name is Paul, I posted just before yours about stopping the Aricept.
Since we have discontinued it over two months ago, we've seen the rapid decline we knew would come. It seems we all have a goal in mind, after mom asked us numerous times if there was anything we could do to give her peace, to give it to her became our goal. She'd been on the medication for nearly 6 yrs. We decided it was time to let her go, and she has been less agitated recently as a result. So we think we've accomplished what we'd set out to do. But as you know, our expectations always have to change with Alzheier's disease. So at any time, the agitation may return. A day at a time, yes?
Now for your goal. Be specific about it with her doctor. Does your mom have a physician that is used to working with the elderly, specifically Alzheimer's patients? Her constant speaking could be a result of agitation? My mom is taking and tolerating Celexa and Remeron for depression, maybe this would help yours? I'll be back later with links to a site where you can compare medications, and another excellent site that has quite a bit of activity.