Parkinson’s Disease Dementia (PDD) leads to acute memory loss. The patients also fail to maintain relationships with others. A drug called rivastigmine is used to reduce symptoms and improve their behavior. But more than 53% of these patients develop orthostatic hypotension (OT). This study looks at the benefits of rivastigmine in PDD subjects with OT.

 About 1047 PDD patients were subjected to randomized control trials. The drug vs placebo usage was compared in 501 subjects at week 24. And rivastigmine patch vs capsule was compared in 546 subjects at week 76. A systolic BP drop >= 20 mmHg and diastolic >= 10 mm Hg categorized them as OH+. Else, they were in OH-group. The primary endpoint for two groups was the Alzheimer’s Disease Assessment Scale‐Cognitive subscale (ADAS‐Cog) at week 24 and the Mattis Dementia Rating Scale (MDRS) at week 76. A posthoc analysis was also done factoring in intention-to-treat in retrieved dropout and observed cases.

The overall safety comparison in OH+ and OH- was 288 with 27.5% and 730 with 69.7%. However, the placebo group with OH+ at 9.2% showed higher syncope. The placebo adjusted drug effect was in favor of the OH+ group at 5.6+/-1.2 while OH- was at 1.9+/-0.9. The OH+ prevalence at 24 weeks was lower in rivastigmine than placebo (28.3% vs 44.6%). The MDRS change in OH+ was higher in capsules vs patch (approx. 10.6 vs -1.5).

Rivastigmine offers cognitive benefits in PDD patients with OH. It is mediated by a direct anti-hypotensive effect.