The pathological hallmark of Parkinson’s is the depletion
of the chemical dopamine from the brain. Management with drugs is based on
replacing the depleted dopamine, either with dopamine itself in the form of
levodopa (Sinemet/Madopar) or using manufactured drugs which mimic the effect of natural
dopamine. These are known as dopamine (or dopa) agonists and examples are
ropinirole (ReQuip) and pramipexole (Mirapexin). Levodopa is considered the
‘gold standard’ in terms of its effectiveness, but often younger patients
(those under the age of 60) will be started on a dopamine agonist in the first
instance. Often patients are maintained on a combination of dopamine agonist
and levodopa. The most frequently used drugs are co-careldopa (Sinemet) and
cobeneldopa (Madopar). Both of these drugs contain levodopa. Once the levodopa
reaches the brain it is changed into dopamine, so makingup for the shortage. Sinemet and Madopar are therefore a
form of replacement therapy – like insulin in the treatment of diabetes.
Although these two drugs are the most used, not everyone with Parkinson’s takes
them. There are several other drugs available thatmay be more appropriate for some individuals at certain
stages.
