Rivastigmine improves the function of nerve cells in the brain. It works by preventing the breakdown of a chemical called acetylcholine (ah SEE til KOE leen). People with dementia usually have lower levels of this chemical, which is important for the processes of memory, thinking, and reasoning. Rivastigmine transdermal (skin patch) is used to treat mild to moderate dementia caused by Alzheimer's or Parkinson's disease. Rivastigmine transdermal may also be used for purposes not listed in this medication guide.