Clozapine, the first second-generation or "atypical" antipsychotic medication, was introduced in the United States in 1989, according to background information in the article. Several additional drugs, including risperidone, olanzapine and paliperidone, followed. Although they are less likely to cause neurological adverse effects associated with conventional or "typical" antipsychotics, some reports have linked atypical antipsychotics to strokes, diabetes and other severe adverse events. In April 2005, the FDA issued a public health advisory that asked manufacturers to include a boxed warning regarding the increased risk of death associated with using atypical antipsychotics to treat behavioral symptoms in older patients with dementia (an off-label use of the drugs).
E. Ray Dorsey, M.D., M.B.A., of the University of Rochester Medical Center, New York, and colleagues analyzed nationally representative data to assess rates of atypical antipsychotic drug use between January 2003 and December 2008. Physicians participating in the national index recorded diagnoses, therapies and patient characteristics for all clinical encounters over a two-day period. The researchers calculated the number of patient-physician interactions during which an antipsychotic was mentioned as a therapy and compared time periods before and after the FDA warning was issued to quantify its effects.
From January 2003 to March 2005, the rate of atypical drug mentions increased 34 percent per year, including a 16 percent increase among patients with dementia. In the year before the FDA advisory, approximately 13.6 million atypical antipsychotic mentions occurred, 0.8 million of which involved patients with dementia.
An overall decline in the use of atypical medications began within one month of the FDA advisory. Mentions of atypical antipsychotics decreased 2 percent overall and 19 percent among those with dementia in the year following the warning; by 2008, monthly drug uses among elderly patients with dementia decreased more than 50 percent.
The use of these medications for both FDA-approved and off-label indications continued decline for all populations through the end of the study period (December 2008). However, despite the uncertain benefits and the decrease in use among elderly patients with dementia, atypical antipsychotics still comprised 9 percent of prescription drug uses for dementia among older adults by the end of 2008.
"The residual use in the population at risk and the decrease in the use of atypical antipsychotics in the general population, who were not targeted by the warning, raise the question as to whether the effect and specificity of FDA regulatory actions could be enhanced," the authors conclude. "Targeting specific segments of patients and physicians (e.g., high prescribers) and further customizing and evaluating the impact of regulatory actions may improve their impact at minimizing the risks associated with select prescription medications."