Rivastigmine in subcortical vascular dementia: an open 22-month study

Further to recent data indicating that patients with vascular dementia (VaD) show a cholinergic deficit, we aimed to determine whether rivastigmine, a dual inhibitor of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), has any effects on the symptoms of VaD. Patients aged 65-80, with a diagnosis of dementia and probable VaD, received rivastigmine 3-6 mg/day (n=8) or cardioaspirin (n=8) in an open study for 22 months. At 22 months, patients treated with rivastigmine showed significant improvements in executive function and behavioural symptoms (both p<0.05 vs. both baseline and control group), which were reflected in reduced caregiver stress (p<0.05 vs. baseline and controls). Baseline scores of global response, cognition, word fluency and activities of daily living were maintained in patients receiving rivastigmine, and there was no increase in benzodiazepine or neuroleptic intake. In contrast, the control group showed no improvements in any domain, and significant deterioration in global response and executive function (both p<0.05 vs. baseline and rivastigmine group). Side effects in both groups were tolerable and there were no study withdrawals. Long-term rivastigmine treatment appeared to be safe and effective in this patient population. In particular, improvements in domains particularly relevant to this condition were observed. These benefits may reflect the drug's dual inhibitory effects on the cholinergic system, and its particular activity in frontal areas of the brain. A large, double-blind study of rivastigmine in patients with VaD would be worthwhile.