Fewer side effects observed with 9.5-mg transdermal rivastigmine when compared with oral capsules in Alzheimer's disease treatment

A transdermal rivastigmine patch is as effective as twice-daily oral treatment and is associated with 3 times fewer reports of nausea and vomiting, according to results of the Investigation of Transdermal Exelon in Alzheimer's Disease (IDEAL) trial reported at the 131st Annual Meeting of the American Neurological Association in Chicago, Ill.

A transdermal rivastigmine patch is as effective as twice-daily oral treatment and is associated with 3 times fewer reports of nausea and vomiting, according to results of the Investigation of Transdermal Exelon in Alzheimer's Disease (IDEAL) trial reported at the 131st Annual Meeting of the American Neurological Association in Chicago, Ill.

IDEAL included 1,195 patients randomized to use a transdermal patch delivering either rivastigmine 9.5 mg (n=291) or 17.4 mg (n=303) every 24 hours, conventional treatment consisting of 1 rivastigmine 6-mg capsule twice daily (n=294), or placebo (n=302) for 24 weeks. Patients had a baseline score of 10 to 20 on the Mini-Mental State Examination (MMSE).

Primary outcome measures were the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) and the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC). Secondary outcome measures were MMSE score and assessment of activities of daily living, behavior, executive and visuospatial function and attention, visual tracking, and motor processing speed.

The 9.5-mg patch significantly reduced the common side effects of nausea and vomiting compared with oral treatment, whereas the 17.4-mg patch produced nausea and vomiting at rates similar to those observed with oral treatment. Among patients receiving oral treatment, 23.1% reported nausea and 17% reported vomiting. Among those using the 17.4-mg rivastigmine patch, the rates were 21.1% and 18.8%, respectively. Patients using the 9.5-mg patch demonstrated a 7.2% incidence of nausea and a 6.2% incidence of vomiting.

Results of a questionnaire distributed to caregivers of IDEAL study patients demonstrated that 70% of caregivers preferred transdermal rivastigmine administration versus oral treatment.

SOURCE Winblad B, Cummings J, Zechner S, et al. IDEAL: A 6-month placebo-controlled study of the first transdermal patch in Alzheimer's disease–rivastigmine patch versus capsule [abstract]. Presented at: 131st Annual Meeting of the American Neurological Association; Chicago, Ill; October 8–11, 2006; Abstract M88.