Benefits Found in Two Drugs Used to Treat Hallucinations in Parkinson's
Two drugs used
to treat hallucinations in patients with Parkinson's disease (PD) can
not only reduce hallucinations, but may also lead to long-term benefits
in these patients, according to a group of Emory University researchers.
The long-term benefits may include reduced mortality and a reduced risk
of nursing home placement. The drugs studied were the atypical
antipsychotics quetiapine (trade name Seroquel®) and clozapine (trade
Jorge Juncos, M.D., associate
professor of neurology, Emory University School of Medicine, and colleagues
will present their findings at the American Academy of Neurology 54th
Annual Meeting in Denver, Colo., on April 18. The research will also
appear as an abstract in the April issue of the journal, Neurology.
"Drug-induced psychotic symptoms,
such as visual hallucinations, are seen in a significant number of patients
with advanced PD," says Dr. Juncos. "Approximately 15 to 20 percent
of PD patients may experience these hallucinations over time. They are
due to a interaction between the progression of the illness and the
drugs used to treat its symptoms," Dr. Juncos explains.
The Emory researchers conducted
a retrospective chart review between 1996 and 2001 in 27 patients with
advanced PD (mean duration of illness of 13 years, plus or minus six
years). Hallucinations had been treated for approximately 36 months
using quetiapine in 23 patients and clozapine in four patients. "We
compared the antipsychotic efficacy, mortality and risk of nursing home
placement to published historical data (Goetz & Stebbins, Neurology
1996) in similarly affected patients treated with low doses of typical
anti-psychotics before 1996," Dr. Juncos says.
Based on clinical exams or
caregiver reports, Emory researchers found hallucinations in these patients
were reduced by almost half (from 100 to 59 percent) while patients
were on one of the study medications. Symptoms of agitation were also
reduced (from 37 to 19 percent). During the 36 months of observation,
the mortality rate for the group was 52 percent for outpatients and
62 percent for nursing home residents. This mortality rate is somewhat
higher than the estimated general mortality rate of 36 percent for all
PD patients after 13 years of illness. However, this mortality rate
is lower than the mortality rate of 80 percent reported prior to 1996
for patients with PD and hallucinations residing in nursing homes and
treated with typical antipsychotics. By the end of the 36-month follow-up,
50 percent of hallucinating PD patients had been placed in nursing homes.
That number was a significant improvement from the 80 percent reported
by others before 1996.
"These preliminary results
support the view that quetiapine and clozapine may have long-term benefits
in PD patients with hallucinations," Dr. Juncos says. "This benefit
may translate into reduced mortality and a reduced risk of nursing home
The Emory University American
Parkinson Disease Association Center of Excellence in PD Research and
the Fauver Family Foundation supported this study.
Parkinson's disease is a
progressive disorder of the central nervous system, affecting over one
million people in the United States.