Scientists at the University of Pennsylvania's School of Medicine have designed an implantable device capable of delivering anti-psychotic medication for a period of five months, and continuing work at Penn indicates that such devices may work for up to a full year. The device has been proven effective in initial laboratory studies, and more research is underway (in collaboration with the University of Pittsburgh School of Medicine) to lead to potential clinical trials.
Findings from the small-mammal study appear in the current issue of the scientific journal Neuropsychopharmacology. If the device can be demonstrated to work effectively in human subjects in future trials, it will offer a medical alternative that may relieve many patients of the threat of psychosis and chronic social instability.
"Schizophrenia destroys an individual's grasp of reality, robbing him of his identity and devastating his family," said Steven Siegel, MD, PhD, of the Division of Neuropsychiatry in Penn's Department of Psychiatry. This device could relieve those threats, by assuring medical stability.
"Patients who need anti-psychotic drugs often fail to comprehend the profound severity of their illness, and may stop taking their medication during temporary periods of impaired judgement. But when the majority of patients with psychiatric disorders take appropriate medicine, they do achieve periods of remission from psychotic symptoms." Siegel said. "The advantage of relying on an implantable anti-psychotic medicine is that patients are able to make decisions about the future course of their treatment during periods of relative health, but if a medical reason arises that necessitates curtailing treatment, the implant can be easily removed."
The delivery device consists of a surgically-implantable disc made of biodegradable polymers (a series of linked molecules) combined with medication. In the trials, a traditional anti-psychotic medicine, Haloperidol, was used. The discs have been modeled in a fashion that allows each type of polymer to disintegrate at a specific rate, so that exactly the prescribed volume of medication is released into the bloodstream each day for up to a year. About the size of a quarter, the device is held in place under the skin with a single surgical stitch. According to Siegel, the implantation procedure (and removal procedure) can be performed in about 15 minutes under local anesthetic.
Other Penn researchers who collaborated in the study are: Karen I. Winey, PhD, Department of Materials Science and Engineering; Raquel Gur, MD, PhD, and Robert H. Lenox, MD, Department of Psychiatry; Warren B. Bilker, PhD, Department of Biostatistics and Epidemiology, and Debbie Ikeda, Neel Gandhi, and Wen-Xiao Zhang, MS, also of Psychiatry.
Siegel's work is supported by the Stanley Foundation, an advocacy organization for families of individuals afflicted with schizophrenia. He has been named director of the newly formed Stanley Center for Experimental Therapeutics in Psychiatry at Penn. A patent application for the implant technology is pending.