Which medication is primarily used for dementia due to Parkinson's disease and should be used with caution in PD patients?

Rivastigmine is primarily indicated for the treatment of dementia associated with Parkinson's disease due to its efficacy in improving cognitive function in patients suffering from both Parkinson's and dementia. It is a dual inhibitor of both acetylcholinesterase and butyrylcholinesterase, which enhances cholinergic neurotransmission that can be impaired in dementia.

This medication should be used with caution in Parkinson’s disease patients primarily because it can exacerbate symptoms of bradykinesia and tremor in some cases. The cholinergic side effects might interact with the already compromised dopaminergic pathways, hence careful monitoring is advised when administering Rivastigmine to this population.

While other medications mentioned can be used in dementia or have relevance in Parkinson's treatment, Rivastigmine stands out due to its specific application in treating dementia related to Parkinson’s disease and the need for careful management to avoid worsening motor symptoms.