The effects of commonly prescribed drugs in patients with Alzheimer’s disease on the rate of deterioration

Background: Prescribed drugs in patients with Alzheimer’s disease may affect the symptomatic progression of their disease, both positively and negatively. Aim: To examine the effects of drugs on the progression of disease in a representative group of patients with Alzheimer’s disease. Methods: Patients with the diagnosis of probable Alzheimer’s disease were recruited from the community. The prescribed drugs taken by 224 patients (mean age 82.3 years) were recorded at initial assessment and then correlated in logistic regression analysis with progression of the disease, defined as an increase of one point or more in the Global Deterioration Scale over the next 12-month period. Results: Patients who were taking antipsychotic drugs and sedatives had a significantly higher risk of deterioration than those who were taking none (odds ratios (ORs) 2.74 (95% confidence interval (CI) 1.17 to 6.41) and 2.77 (95% CI 1.14 to 6.73), respectively). Higher risk of deterioration was observed in those who were taking both antipsychotic and sedative drugs together (OR 3.86 (95% CI 1.28 to 11.7). Patients taking drugs licensed for dementia, drugs affecting the renin–angiotensin system and statins had a significantly lower risk of deterioration than those who were not taking any of these drugs (ORs 0.49 (95% CI 0.25 to 0.97), 0.31 (95% CI 0.11 to 0.85) and 0.12 (95% CI 0.03 to 0.52), respectively). Conclusion: Our findings have implications for both clinicians and trialists. Most importantly, clinicians should carefully weigh any potential benefits of antipsychotics and benzodiazepines, especially in combination, against the risk of increased decline. Researchers need to be aware of the potential of not only licensed drugs for dementia but also drugs affecting the renin–angiotensin system and statins in reducing progression in clinical trials.