Although the second-generation ChE inhibitors are generally well tolerated do not exhibit the hepatotoxicity associated with tacrine, they differ with regard to safety and tolerability profiles. In clinical trials,the discontinuation rates due to adverse events were 5% and 7% for donepezil galantamine, respectively, with neither differing significantly from placebo. However, 15% of patients discontinued rivastigmine treatment, compared with approximately 5% of patients receiving placebo.