Clinical Geriatrics

American Association for Geriatric Psychiatry 2010 Annual Meeting
Savannah, GA; March 5-8, 2010

Poster

Effects of Rivastigmine Transdermal Patch on Cognitive Ability in Patients with Mild-to-Moderately Severe AD

Savannah, GA—In their study examining the specific effects of rivastigmine on individual Alzheimer’s Disease Assessment Scale-Cognitive subscale (ADAS-Cog) items and cognitive domain scores, George T. Grossberg, MD, St. Louis University School of Medicine, St. Louis, MO, and colleagues found that the rivastigmine patch is associated with improved cognitive function in persons with mild-to-moderate Alzheimer’s disease (AD). In addition, all rivastigmine groups showed statistically significant improvements in the memory and praxis domains of cognition; the rivastigmine patch provided statistically significant improvement in the language domain, and the larger patch (17.4 mg/24 hr) showed the most benefits on individual ADAS-Cog items. Finally, researchers concluded that a tendency for superior efficacy with the rivastigmine patch versus capsules might reflect easier access to target doses due to an improved gastrointestinal profile with patch delivery.

The rivastigmine transdermal patch has been shown to improve cognition in patients with mild-to-moderate AD using the ADAS-Cog. In this analysis, researchers further assessed the cognitive effects of the patch with ADAS-Cog subscales and items. This was a retrospective analysis of the Investigation of transDermal Exelon in ALzheimer’s disease (IDEAL) study, a 24-week, randomized, placebo- and active-controlled clinical trial comparing the efficacy and safety of the rivastigmine patch (9.5 mg/24 hr and 17.4 mg/24 hr), rivastigmine capsules (12 mg/day), and placebo in mild-to-moderate AD. Baseline to week 24 changes were calculated for each ADAS-Cog subscale (memory, language, praxis) score and item score using the Intent-To-Treat Last Observation Carried Forward (ITT-LOCF). Treatment differences were evaluated for each subscale score using an analysis of covariance (ANCOVA) model with treatment and country as factors and baseline as covariate, and for each item score using the van Elteren test, blocking for country. The study population had a mean age of 74 years and was two-thirds female. Two-hundred ninety-three patients were randomized to 9.5 mg/24 hr rivastigmine patch, 303 patients to 17.4 mg/24 hr rivastigmine patch, 297 patients to 12 mg/day rivastigmine capsule, and 302 patients to placebo. ADAS-Cog data were provided by 1044 patients across the 9.5 mg/24 hr rivastigmine patch, 17.4 mg/24 hr rivastigmine patch, rivastigmine capsule, and placebo groups.

Results of this poster session, presented at the annual AAGP meeting, revealed that all rivastigmine groups showed significant effects versus placebo on the overall ADAS-Cog score (all P < 0.01). Patients taking 9.5 mg/24 hr and 17.4 mg/24 hr rivastigmine patches showed improvements over placebo on the memory, language, and praxis ADAS-Cog subscales; those taking rivastigmine capsules showed improvements on the memory and praxis subscales (all P < 0.05). Improvements on individual ADAS-Cog items versus placebo were seen for the 9.5 mg/24 hr rivastigmine patch on word recall, naming, and ideational praxis; for the 17.4 mg/24 hr rivastigmine patch on word recall, following commands, constructional praxis, naming, ideational praxis, word recognition, recall of test instructions, language ability, and word-finding; and for rivastigmine capsules on word recall, constructional praxis, ideational praxis, and recall of test instructions (all P < 0.05).