The third trial compared donepezil with rivastigmine over 2 years. Patients taking rivastigmine fared significantly better in function and some measures of behavior, but experienced more adverse events than did those receiving donepezil.
The guideline writing panel attempted to address the appropriate duration of therapy; however, the response to pharmacotherapy varies so widely. Generally, the beneficial effect from any of the drugs–disease stabilization or symptom improvement–will be apparent within 3 months of initiating treatment but will be temporary. When slowing decline is no longer a therapeutic goal, “treatment with a cholinesterase inhibitor or memantine is no longer appropriate.”
Honest communication at the time of diagnosis is the best way to optimize medical therapy, according to Dr. David A. Smith, professor of family medicine at Texas A&M University, College Station. When families and patients understand up front that the benefit from these drugs will be modest and temporary, they are more likely to stick with the treatment plan, squeezing every possible benefit from it. “A lot of people do get started on these drugs, but the dropout rate is huge, because there is this expectation of large benefit,” he said. “But it's important to remember that even small changes in cognition and behavior can roll into bigger changes over time, like in the rate of institutionalization.”
Dr. Thies agreed. Despite their limitations, these drugs are the best that we have, and you don't want patients to throw away the only opportunity that we do have, he said. “You want the patient and family to go into therapy with a rational view of what is going to happen. The more they know about what to expect, the better they will do.”
Early diagnosis is key to getting everyone on the same page about expectations, Dr. Thies said. “If someone with Alzheimer's is to get into this discussion in a rational fashion, early diagnosis is critical. That way, patients can be involved in determining not only the course of therapy, but [also] can express their opinions on placement and end-of-life care. All these questions become much easier if the patient is involved, rather than having the family guess about his wishes at a later point.”