Because the loss of dopamine in the brain is the fundamental
problem of Parkinson's disease, treatment is focused on replacing
dopamine to help counter the loss of motor function. Dopamine
loss is not the only mechanism involved; finding other,
still-unknown factors is a major challenge facing researchers.
Until we have the answers, however, drug makers will continue to
design medications aimed at helping the brain replace the missing
When symptoms warrant treatment, your neurologist will consider
several types of medications to reduce tremor and ease movements.
Sinemet is the gold standard of treatment for Parkinson's
disease. Levodopa is an amino acid that the brain converts into
dopamine; it is combined with carbidopa, which does not enter the
brain but blocks the enzyme that converts levodopa into dopamine
in other parts of the body. Thus it essentially keeps levodopa
intact until it reaches the brain. By restricting the release of
dopamine in the stomach, carbidopa greatly decreases some of the
unpleasant side effects associated with levodopa alone, including
nausea and bursts of uncontrollable movements. However, when
Sinemet is taken at high doses, it can also cause nausea. Other
possible side effects include mental confusion, episodes of low
blood pressure, sleep disturbances, and delusions.
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