Psychiatryniche
A 76-year-old man with dementia with Lewy bodies has become convinced that his son is stealing from him and has started accusing and shoving care staff. Over three weeks a change of key worker, a revised daily routine and reassurance have not helped, and pain, constipation and infection have been excluded. He has spontaneous parkinsonism and has fallen twice this month. His blood pressure is 128/76 mmHg, he is not diabetic, and he has no history of stroke or atrial fibrillation. Which one of the following is the most appropriate drug treatment?