Drug therapy is an important part of the treatment for Parkinson’s disease, a progressive neurologic disorder characterized by four cardinal features:
· muscle rigidity (inflexibility)
· akinesia (loss of muscle movement)
· tremors at rest
· disturbances of posture and balance.
Parkinson’s disease affects the extrapyramidal system, which in-fluences movement. The extrapyramidal system includes the cor-pus striatum, globus pallidus, and substantia nigra of the brain.
In Parkinson’s disease, a dopamine deficiency occurs in the basal ganglia, the dopamine-releasing pathway that connects the substantia nigra to the corpus striatum.
Reduction of dopamine in the corpus striatum upsets the normal balance between two neurotransmitters, acetylcholine and dopamine. This results in a relative excess of acetylcholine. The excessive excitation caused by cholinergic activity creates the movement disorders that characterize Parkinson’s disease.
Parkinson’s disease can also result from drugs, encephalitis, neu-rotoxins, trauma, arteriosclerosis, or other neurologic disorders and environmental factors.
The goals of drug therapy are to provide relief of symptoms and to maintain the patient’s independence and mobility.
Drug therapy for Parkinson’s disease is aimed at correcting the imbalance of neurotransmitters by:
· inhibiting cholinergic effects (with anticholinergic drugs)
· enhancing the effects of dopamine (with dopaminergic drugs).