Alzheimer's disease (AD) is often associated with multiple comorbidities and subsequent polypharmacy. Treatment of AD with acetylcholinesterase (AChE) inhibitors can carry a risk of drug interaction with multiple medications often prescribed for other co-existing illnesses. Rivastigmine is an AChE inhibitor that is enzymatically cleaved by AChE, minimally metabolized by cytochrome P450 enzymes, has low protein binding, has a short plasma half-life, and a relatively short duration of action. Such properties make it ideal for use in this patient population. A pharmacodynamic analysis of rivastigmine administered concomitantly with other medications (22 different therapeutic classes) did not reveal any significant pattern of increase in adverse events that would indicate a drug interaction. In summary, rivastigmine was well tolerated and safely administered to a population receiving multiple medications for 'real-world' comorbidities.