Tea splashes onto an age-yellowed kimono as Akemi K, 67,
goes through the complex motions of the tea ceremony with
shaking hands. Despite her obvious concentration and daily
levodopa tablets, Akemi is still troubled by the shaking,
stiffness, slow movement, poor balance and other difficulties
that characterize Parkinson's disease. A study published
in the March 12 issue of the Lancet offers some
hope to folks like Akemi, as it describes how motor function
may be further improved by a once daily oral dose of rasagiline.
Dr Olivier Rascol of the University
Hospital in Toulouse, France, and his colleagues recruited
687 Parkinson's disease patients from 74 medical centres
in Israel, Argentina and Europe. All the patients were
already on levodopa and were experiencing periods of
greater and lesser motor difficulties with this drug.
In the 18-week study, 231 folks
were assigned to daily 1mg oral doses of rasagiline
— a drug that irreversibly blocks the activity
of dopamine-degrading monoamine oxidase B — with
each dose of levodopa. Another 227 patients received
200mg of entacapone, an inhibitor of catechol-O-methyltransferase,
with each levodopa dose. The remaining 229 folks received
a placebo. Both patients and evaluators were unaware
of who was receiving rasagiline, entacapone and placebo.
The primary outcome that was assessed
was the daily length of time that symptoms were absent
or minimal after the effects of the medication had worn
off ("off-time"). As well, the clinical global improvement
(CGI) and unified Parkinson's disease rating scale (UPDRS)
scores were determined.
Of the 687 subjects who began the
study, 88 did not complete it. Of these, 23 were receiving
rasagiline, 30 entacapone and 35 placebo. Thirty-four
patients simply decided not to continue, while 34 experienced
some adverse reaction, with the frequency being similar
for all three treatments.
COMPLEMENTARY
DRUG COMBO
Mean daily off-time was reduced by rasagiline (-1.18
hours) and entacapone (-1.2 hours), as compared to placebo
(-0.4 hours). Put another way, when the effectiveness
of the drugs had worn off, more of the day was spent
symptom-reduced or symptom-free. Moreover, the rasagiline
and entacapone crowd enjoyed an increased length of
time free of the rapid involuntary muscle movement that
is a hallmark of Parkinson's as compared to the placebo
group.
UPDRS off-time scores that reflected
everyday activities were significantly better for rasagiline
and entacapone compared to placebo. Furthermore, when
the drugs kicked in, motor function was significantly
better in these two groups.
"Once-daily rasagiline reduces
mean daily off-time and improves symptoms of Parkinson's
disease in levodopa-treated patients with motor fluctuations,
an effect similar to entacapone," conclude the researchers
in the Lancet paper. This important research
provides more treatment options for doctors with patients
who suffer from Parkinson's disease.
Lancet Mar 12, 2005;365:947-54
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