Zygmunt Jamrozik, Piotr Janik
Med Sci Monit 1997; 3(6): RA948-955
The efficiency of long time treatment by levodop of Parkinson's disease (PD) is limited to occurrence of side syndromes in the form of movement disorders such as: fluctuations, diskinesia, the decrease of effectiveness of the drug. The causes of their occurrence connected with loss of dopaminergic cells, pharmacodynamics, pharmacokinetic of levodop, changes in affinity of dopamine receptors (D), pathology of other structures outside the nigrostrial pathways. The discovery of the family of dopamine receptors D1, D2, D3, D4 and D5 and their differentiated effect on the functions of exrapyramidal system allowed the use of the strategy of more selective reaction on particular receptors. Dopamine receptor agonists (DAAG) have some positive characteristics from the clinical point of view and theoretical comparison to levodop. Those drugs are not metabolized to active chemicals, do not produce toxic metabolites or free radicals, their effectiveness in a smaller degree is depended on degree of damage of presynaptic elements. DAAG effectively brings back the balance in the neurotransmission of neuropeptides in striatum and decrease rotation of endogenic dopamine. Among actually available DAAG at least three have potential neuroprotective action. Former clinical xperiments show that use of this drugs is particularly desirable in two groups of patients. First consists of young patients, that had been not treated yet, particularly successible to fast occurrence of levodopic complications, in whom the use of DAAG in monotherapy allows to decrease the risk of far complications. The second group consists of patients treaded with levadop, with developed side symptoms, which cannot be satisfactorily control with the help of antycholinergic drugs, amontadine, benzodiazapine.
Keywords: basal ganglia, dopaminergic receptor agonists, Parkinson Disease