A review of some aspects of the pharmacology of levodopa.
Levodopa has become established as the treatment of choice in Parkinson's disease. It is adsorbed by an active mechanism from the small bowel. Its pharmacological activity depends upon the formation of dopamine and possibly other metabolites. Its beneficial effect in Parkinson's disease probably depends upon temporarily restoring the ability of degenerating nigro-striatal cells to release dopamine. Its main side effect, that of dyskinesia, may reflect a direct action of dopamine on striatal receptors. Peripheral decarboxylase inhibitors reduce the incidence of levodopa-induced nausea, probably by lowering the concentration of dopamine in the area postrema. The introduction of levodopa in the treatment of Parkinson's disease is generally regarded as one of the uncommon examples in medicine where effective therapy has resulted from systematic research rather than seredipity. As our knowledge of the pharmacology of levodopa grows, we may be forced to admit that perhaps the right drug was chosen for the wrong reasons.
D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D001145:Arrhythmias, Cardiac / Q000139:chemically induced; D002319:Cardiovascular System / Q000187:drug effects; D055598:Chemical Phenomena; D002621:Chemistry; D003342:Corpus Striatum / Q000187:drug effects; D003692:Delayed-Action Preparations; D004298:Dopamine / Q000096:biosynthesis; D006801:Humans; D007024:Hypotension, Orthostatic / Q000139:chemically induced; D007408:Intestinal Absorption; D007980:Levodopa / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D009325:Nausea / Q000139:chemically induced; D009434:Neural Pathways / Q000187:drug effects; D010300:Parkinson Disease / Q000188:drug therapy; D011954:Receptors, Dopamine / Q000187:drug effects; D013378:Substantia Nigra / Q000187:drug effects; D014018:Tissue Distribution; D014839:Vomiting / Q000139:chemically induced
D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D003692:Delayed-Action Preparations; D011954:Receptors, Dopamine; D007980:Levodopa; D004298:Dopamine