https://www.jstage.jst.go.jp/article...11/52_890/_pdf

The current approach to the treatment of Parkinson’s dis‑
ease (PD) can be divided into the following considerations:
a) Disease modifying therapy―no treatment has as yet
been determined to slow the rate of disease progression.
Nonetheless, recent studies demonstrate that the early initia‑
tion of rasagiline 1 mg provides benefits that cannot be
achieved with delayed introduction of the same treatment,
consistent with a disease modifying effect. Further, clinical
and basic research suggests that early treatment may pre‑
serve beneficial compensatory mechanisms and thereby de‑
lay clinical progression. New drugs and new targets are be‑
ing actively explored.
b) Early symptomatic therapy―current treatment ap‑
proaches now advocate considering initiation of therapy at
the time of diagnosis to maximize long‑term benefit. Levo‑
dopa remains the standard therapy for PD but chronic treat‑
ment is associated with motor complications. Many neurolo‑
gists favor initiation of treatment in appropriate candidates
with dopamine agonists to reduce the risk of motor complica‑
tions. However, More recent
studies show that treatment
levodopa‑induced motor complications are extremely dose‑
related and can be minimized by using low doses while
avoiding side effects associated with dopamine agonists.
Eventually, most patients are best treated with low doses of
polypharmacy.
c) Therapy of advanced disease―The addition of MAO‑B
inhibitors, COMT inhibitors and dopamine agonists have all
been shown to reduce levodopa‑induced off time. There are
no approved medical therapies for dyskinesia, but amanta‑
dine has been show to have some benefit in double blind tri‑
als. Prevention is the best approach, and many new classes of
molecules such as A2a antagonists and glutamate antago‑
nists are currently being investigated.
d) Non‑motor features―problems such as freezing, falling
and dementia remain a major source of disability for many
PD patients and no effective therapies are currently avail‑
able.
Therapy for PD patients must be individualized. A neuro‑
protective therapy, a symptomatic therapy that avoids mo‑
tor complications, and effective treatments for the non‑motor
features of the disease remain unmet needs, but advances
continue to be made in these areas.
※The authors declare there is no conflict of interest relevant to
this article.