|Drug therapy for Parkinson's disease
“People are on
different drugs, so it is important to know what they are, what the side
effects are and what the positive results are”
disease (PD) cannot be cured by drugs, but they can make a huge difference
to symptoms and improve quality of life.
severity of PD symptoms varies greatly from one person to another. Not
everyone needs drug treatment at first, but nearly all find that drugs
help as symptoms progress. It is impossible to suggest any one drug that
is best. All have their place and can be useful.
general, PD drugs are most effective at treating slowness of movement and
muscle stiffness. They are less effective against poor balance, speech
problems and slowness of thinking and memory difficulties.
which replace dopamine in the brain (levodopa preparations, including Sinemet/Co-careldopa
and Madopar/Co-beneldopa) are used most widely and are regarded
as the ‘gold-standard’. They come in various strengths and
which mimic dopamine the dopamine agonists, including ropinirole (Requip),
cabergoline (Cabaser), pramipexole (Mirapexin) and
bromocriptine (Parlodel) are newer. Some specialists think that using them early delays need for
levodopa and reduces long term side effects. They can be used alone, or
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common PD drugs include selegiline (Eldepryl), amantadine (Symmetrel),
and the COMT inhibitor drug, entacapone (Comtess). These are usually
used with levodopa or a dopamine agonist. The anticholinergic drugs trihexyphenidyl/
benzhexol (Disipal), orphenadrine and procyclidine (Kemadrin) cause
side effects in older people and are seldom useful (except if tremor is
people have side effects of nausea, dizziness, sleep disturbance,
hallucinations or confusion when they first start PD drugs. These usually
can be controlled with adjustment of the dose, or time it is taken,
especially in relation to food. Using an additional anti-sickness drug,
called domperidone, may sometimes help.
best dose of the drugs can only be found out by trial and error. Usually a
very low dose is first given and gradually increased until the best effect
months or a few years, the drugs can become less effective, taking longer
to act and wearing off abruptly (known as on/off phenomenon). New side
effects of involuntary muscle twisting movements (known as dyskinesias)
can also develop. Extra care is then needed with timing and dosing of the
drug and changing, or adding another drug, may be appropriate.
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