Hello.
My Mum was on Memantine for a few years. she suffered no side effects.
Mum was put on it too late (very long story) for her to reap the full benefit of this drug.
We were told
It was likely to take a while before we noticed any improvement
It only works for a few months
It could help with mums agitation
Their could be side effects.
It does not work for everyone
What we found.
Within a few days, Mums almost daily deterioration stopped seemingly overnight, sadly mum never actually improved but at least she was getting no worse.
It stopped mum getting any worse for over two yrs. and when we noticed mum was declining again, it was very slow unlike before she was put on it, so we and her Consultant reckoned it was still helping , he went against the guidelines here in the uk and kept her on it till she died, I was very glad he did this.
It did not help at all with mums agitation
Mum suffered no side effects, though many on here have reported unpleasant side effects
or worsening of dementia symptoms.
I am afraid to say , it is a matter of trial and error, unlike some other illnesses, Medication that works for one person, with Dementia may not help another.
If you have specific worries about this medication , please ask, people here will do their best to help