Combination Therapy for Alzheimer's Disease

Evidence Supporting Combination Therapy

The American College of Physicians guidelines support adding memantine to donepezil, noting statistically significant improvements in global assessment, quality of life, and caregiver burden in patients with moderate to severe disease 1, 2

There is no evidence that adding an antidepressant improves cognitive decline in Alzheimer's disease 1
Sertraline would only be appropriate if the patient had comorbid depression, which is not mentioned in this scenario 3
While one trial showed rivastigmine had marginally better outcomes than donepezil in some measures, rivastigmine had significantly higher rates of adverse events, particularly nausea 1, 2
No convincing evidence demonstrates that one cholinesterase inhibitor is more effective than another 1
Switching between cholinesterase inhibitors is only reasonable if the patient cannot tolerate donepezil, which is not the case here 3, 4

Modest improvements or stabilization in cognition and function over 24-26 weeks can be expected with combination therapy 5, 2
The combination is generally well tolerated, with adverse events occurring in 8-13% of patients 5
Withdrawal rates due to adverse events are similar to placebo (8-12% vs 7-13%) 2

The benefits of combination therapy are statistically significant but modest 1, 2
Set realistic expectations with the patient and family that this represents slowing of decline rather than dramatic improvement 3