Efficacy and safety of switching from oral cholinesterase inhibitors to the rivastigmine transdermal patch in patients with probable Alzheimer's disease

Background and purpose: The goal of this study was to estimate the efficacy and safety of the rivastigmine transdermal patch in patients with probable Alzheimer's disease (AD) who cannot tolerate or do not respond to oral cholinesterase inhibitors (ChEIs).

Methods: A 24-week, prospective, open-label, single-arm, multicenter study was conducted from June 2009 to June 2010 in patients with probable AD. The enrolled patients had either a poor response or a decline in global function after treatment with oral ChEIs, or they were not able to tolerate treatment with oral ChEIs due to adverse events such as nausea or vomiting. A poor response was defined as a decrease of at least 2 points on the Korean version of the Mini-Mental State Examination (K-MMSE) within the previous 6 months (the decline in global function was determined by the investigator or caregiver). The efficacy of treatment was assessed using a follow-up Clinical Global Impression of Change (CGIC) assessment and K-MMSE conducted after 24 weeks, and safety was measured by the occurrence of adverse events and patient disposition.

Results: In total, 164 patients aged 74.7±7.52 years (mean±SD) and with 5.12±3.64 years of education were included. The study was completed by 70% of the patients (n=116), with 12.2% discontinuing due to adverse events. The most frequently reported adverse events (11%) were skin lesions, such as erythema or itching, followed by gastrointestinal problems (1.2%). Either an improvement or no decline in CGIC scores was reported for 82% of the patients.

Conclusions: The immediate switching of patients from an oral ChEI to the rivastigmine transdermal patch without a washout period was safe and well tolerated by the probable-AD patients in this study.