Levodopa - epgonline.org

ENT416_NURSES LEAVEPIECE.qxd 2/10/06 14:08 Page 5
Levodopa: the most effective
therapy for Parkinson’s disease
• As PD is caused by reduced levels of dopamine in the brain, replacing
dopamine with levodopa (a precursor to dopamine) or mimicking its
action with dopamine agonists are key approaches to treatment
• Patients have fewer symptoms and function better with levodopa than
with other dopaminergic therapies
Mean change from baseline
–16
–14
–12
–10
–8
–6
–4
–2
0
Better overall
function* with
levodopa vs
the dopamine
agonist
pramipexole
over 4 year
follow-up 1
2
4
0 6 12 18 24 30 36 42 48
Months from randomization
Levodopa/DDCI Pramipexole
n=301; 72% of
pramipexole group
required open-label
levodopa with a
mean total daily
levodopa dosage
434 ± 498 mg/day.
DDCI=dopa-decarboxylase inhibitor
• The superiority of levodopa to dopamine agonists in patient function
and side-effects has been repeatedly demonstrated 1–3
– Patients with levodopa experience better overall function*, activities
of daily living and motor function compared with those receiving the
dopamine agonists pramipexole, pergolide and ropinirole
– Levodopa therapy has a lower incidence of side-effects than dopamine
agonists. Common side-effects associated with both levodopa and
dopamine agonists include nausea, vomiting and postural hypotension.
However, psychiatric symptoms such as hallucinations and psychosis are
more common with agonists than with levodopa and are particularly prone
to occur in elderly or patients with cognitive difficulties. Other adverse
events such as impulse control disorders, edema and fibrosis have been
associated with dopamine agonist use, although these are relatively rare