IDEAL: Transdermal as Effective as Oral Therapy for Alzheimer's
Patch Better Tolerated by Patients, Preferred by Caregivers
CHICAGO—Transdermal delivery of rivastigmine (Exelon) in patients with Alzheimer’s disease (AD) significantly reduces the nausea and vomiting commonly associated with oral cholinesterase inhibitor (ChEI) therapy, according to results of the Investigation of Transdermal Exelon in Alzheimer’s Disease (IDEAL) trial, which were presented at the American Neurological Association annual meeting.
In addition, the majority of patient caregivers in IDEAL preferred the investigational transdermal patch. “This mode of administration has the potential to reduce side effects but also provides convenience of use, especially for patients who may be resistant to oral medications,” said Jeffrey L. Cummings, MD, of the University of California, Los Angeles. He added that the patch was as effective as oral treatment.
Oral rivastigmine is indicated for treating symptoms of mild-to-moderate AD and recently became the first ChEI to receive an indication for the treatment of dementia in Parkinson’s disease.
IDEAL was a 24-week, multicenter study of 1195 patients with AD (aged 50-85 years). All had baseline Mini-Mental State Examination (MMSE) scores between 10 and 20. The patients were randomized to conventional rivastigmine treatment with one 6-mg capsule twice daily; a 20-cm patch delivering 17.4 mg rivastigmine applied once daily; a 10-cm patch delivering 9.5 mg rivastigmine applied once daily; or placebo in capsule or patch form.
The primary outcome measures were the scores on the Alzheimer’s Disease Assessment Scale-Cognitive Subscale and the Alzheimer’s Disease Cooperative Study-Clinical Global Impression of Change. Secondary outcome measures were the MMSE score and the patient performance on a range of behavioral and functional tasks. Caregivers’ impressions were assessed by a questionnaire.
The efficacy of the 2 patch dosages was equivalent to that of standard oral therapy, Dr Cummings said. At 24 weeks, all active treatment groups performed significantly better than the placebo groups (P <.05) on the different scales. Although the 17.4-mg patch was associated with an improvement in cognitive function scores compared with the other active treatments, the difference was not significant.
Overall, physicians reported that patients using transdermal rivastigmine seemed to have better memory and concentration skills and performed daily activities better compared with patients receiving placebo.
Patients assigned to the 9.5-mg rivastigmine patch had 3 times less nausea and vomiting compared with those assigned to oral treatment or to the higher-dose patch, he said.
The caregiver survey showed that 70% preferred transdermal administration, saying it made it easier to follow the treatment schedule, provided overall ease of use, and interfered less with daily activities.
Only few local skin reactions were reported, with 6.2% of 17.4-mg patch users and 7.6% of 9.5-mg patch users reporting moderate or severe skin irritation at some time during the study. “These results establish that the 10-cm patch is as effective as the 12-mg daily oral treatment and is associated with 3 times fewer side effects,” Dr Cummings said.
