Volunteers needed for Parkinson's disease studies

http://mednews.wustl.edu/news/page/normal/10544.html

By Jim Dryden

Nov. 8, 2007 -- Researchers at Washington University School of Medicine in St. Louis are seeking volunteers with Parkinson's disease for two studies. One is investigating the effects of antidepressant drugs on depression and motor function. The second study is assessing the safety and effectiveness of a drug for Parkinson's patients who also have psychotic symptoms.

In the NIH-funded depression study, investigators are evaluating paroxetine (Paxil) and venlafaxine XR (Effexor) for their success in alleviating depression and for their potential effect on motor function in Parkinson's patients.

"Depression is very common in patients with Parkinson's disease," says Kevin J. Black, M.D., associate professor of psychiatry, of neurology, of neurobiology and of radiology and the study's principal investigator. "Doctors frequently prescribe a class of drugs called selective serotonin reuptake inhibitors for these patients. But we don't really know how well these drugs work in this population."

The study will monitor depression levels in participants who receive one of the drugs for 12 weeks. Investigators also will monitor motor function. Neither the researchers nor the study volunteers will know which drug subjects have received or whether they have been given an inactive placebo until the end of the study.

"There have been concerns that this class of drugs, known as SSRIs, might affect motor function," Black explains. "They are known to alleviate depression in otherwise healthy people, but because the drugs interact with some of the same brain structures affected by Parkinson's disease, it is important that we take a closer look at its affects in this population to ensure that in attempting to alleviate depression, we aren't creating other problems."

The study will include 12 weeks of treatment with a four-week follow up. It will involve weekly phone calls as well as in-person visits at two, four, six, eight and 12 weeks.

The second study, supported by Ovation Pharmaceuticals, is testing varying doses of a drug called melperone to treat psychosis in patients with Parkinson's disease. Currently, there are no drugs approved specifically for the treatment of psychosis in Parkinson's patients. Typical antipsychotic drugs often cannot be used because they can exacerbate parkinsonian symptoms such as stiffness and tremors.

Newer, atypical antipsychotic agents have been more successful, and one of those drugs, called clozapine (Clozaril) frequently is prescribed to treat psychosis in Parkinson's patients. Unfortunately, some patients can develop significant complications when taking that drug. Other antipsychotic drugs either are not very effective at reducing psychotic symptoms or they worsen motor symptoms, or both.

"Because melperone seems to work through different mechanisms than other antipsychotic drugs, we want to see whether it can alleviate symptoms of psychosis without exacerbating motor problems," Black says.

Patients in the 10-week study will receive melperone syrup or an inactive placebo in syrup. Again, neither the investigators nor the participants will know whether an individual receives an active drug or a placebo until the study's completion. The study will require seven in-person visits during a 10-week period. If participants' symptoms improve, they will have the option of continuing on the drug longer than 10 weeks as part of an open-label phase of the study.

Certain health problems — such as recent heart attacks, previous treatment with the drugs, and the presence of other medical or psychiatric disorders — may exclude some people from participating. All screening tests, study medications and research-related procedures for these studies are free of charge. For more information, call or e-mail Mary Creech at (314) 362-7651 (maryc@npg.wustl.edu) or Elda Shipley at (314) 362-6514 (shipleye@npg.wustl.edu).


Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked fourth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.