In Brief: Alzheimer's drug proves ineffective for delirium
As many as 80% of patients admitted to intensive care units develop delirium, a condition that involves confusion and rapid mental changes (such as alternating between lethargy and agitation). Delirium worsens prognosis and increases the amount of time patients spend in the hospital. Moreover, there's little evidence to show that the standard drug treatment for delirium — antipsychotics or benzodiazepines to control agitation — does any good.
Preliminary research suggested that cholinesterase inhibitors, normally prescribed for patients with Alzheimer's disease, might improve mental functioning in patients with delirium. However, the first large randomized controlled study testing one of these drugs, rivastigmine (Exelon), found that the drug not only worsened delirium in critically ill patients, but also extended hospital stays. Investigators stopped the trial early because they also found that more patients died while taking rivastigmine than while taking a placebo.
Unfortunately, this means that there is no apparent medication "fix" for delirium. However, there are steps that clinicians can take to prevent delirium in some people, and to manage it when it does occur.