Drugs used for cognitive symptoms of Alzheimer's disease.

AD is a devastating disease that is increasing in real numbers as our population ages. The toll on individuals, families, health care, and society will continue to escalate unless more effective treatment approaches are developed. To date, the most effective treatments are those that increase brain ACh levels by retarding the enzymatic breakdown of this neurotransmitter. These agents have proved modestly effective but are far from being the answer to AD. Further, when these drugs are withdrawn, patients rapidly decompensate to the state of disability suffered by those receiving placebo, indicating the deteriorative process continues unabated. The long-term effects on cognition of these drugs also is not known, but most clinicians are not overly optimistic. Other pharmacologic approaches include vitamin E, ginkgo biloba, estrogen, and the nonsteroidal anti-inflammatory drugs. Clinical trials do not robustly support their efficacy at this time, but there are numerous anecdotal reports to promote any or all of these approaches. Newer strategies under study include antiamyloid agents and nootropics (which enhance neuronal metabolic activity). The value of these approaches remains to be confirmed.