Table 2:

Pharmacological interventions for motor symptoms in patients with Parkinson’s disease dementia and those with dementia with Lewy bodies

	Dosing	Adverse effects	Comment
Parkinson’s disease dementia
Simplification of antiparkinsonian treatment regime	Withdraw one at a time in the order: (1) anticholinergic drugs, (2) amantadine, (3) selegiline, (4) dopamine agonists, and (5) catechol-O-methyltransferase inhibitors	Reduction in antiparkinsonian medications can lead to the worsening of motor symptoms	Despite the poor correlation between dopaminergic drug exposure and psychosis,55 a stepwise withdrawal approach might be useful, especially if psychosis is present57
Dementia with Lewy bodies
Levodopa monotherapy	Either co-careldopa or co-beneldopa can be used; start with a low dose and increase slowly; commonly, dementia with Lewy bodies initiation doses (50 mg levodopa equivalent dose, for example co-careldopa 12·5 mg/50 mg, taken one to three times daily) are lower than in patients with Parkinson’s disease	Psychosis, postural hypotension, sedation, nausea, and vomiting	Up to a third of patients might experience improvement; however, a third of these patients might also experience psychotic symptoms (eg, hallucinations or delusions)58,59
Zonisamide	25–50 mg once a day as an adjunct to levodopa	Side-effects include weight loss and decreased appetite	Evidence for use in patients with dementia with Lewy bodies comes from one phase 2 randomised control trial19