Description of the medicine: Levodopa (Levodopum)

LEVODOPA (Levodopum). (-) - 3- (3, 4-Dioxyphenyl) -1-alanine, or 3-hydroxy-1-tyrosine.

Synonyms: Kaldopa, Levopa, Avodopa, Bendopa, Biodopa, Brocadopa, Caldopa, Cicandopa, Dalutrin, Deadopa, Dopacin, Dopaflex, Dopal, Dopar, Doparkin, Dopastral, Doprin, Eldopar, Eurodopa, Larodopa, Levodopa, Levopa, Levopar, Madopan, Medidopa, Oridopa, Pardopa, Parkidopa, Parmidin, Speciadopa, Tonodopa, Veldopa and others.

White crystalline powder, slightly soluble in water, insoluble in alcohol.

Dioxyphenylalanine (abbreviated as dopa, or dopa) is a biogenic substance formed in the body from tyrosine and is a precursor of dopamine, which in turn is a precursor of norepinephrine (see Adrenaline).

In connection with the fact that Parkinsonism lowers the content of dopamine in the basal ganglia of the brain, it is advisable to use substances that increase the content of this amine in the central nervous system for the treatment of this disease. Dopamine itself can not be used for this purpose, since it does not penetrate the blood-brain barrier well. It turned out that instead of dopamine, its precursor, dioxyphenylalanine (dopa), can be used, which, when administered orally, is absorbed, penetrates into the central nervous system, undergoes decarboxylation, turns into dopamine and, replenishing its reserves in the basal ganglia, stimulates dopamine receptors and provides a therapeutic effect in parkinsonism .

As a medicinal product, a synthetic levorotatory isomer of dioxyphenylalanine, L-dopa, is used, which is much more active than the dextrorotatory isomer.

Levodopa is well absorbed when taken orally. The maximum concentration in the blood plasma is observed after 1 to 2 hours after administration. It is allocated to a large extent (over 75%) by the kidneys, in part with feces.

Most of levodopa is converted by decarboxylation in tissues (liver, kidney, intestine) into dopamine, which does not penetrate the blood-brain barrier. To reduce decarboxylation, levodopa is used with dopa decarboxylase inhibitors (see Nakom, Madopar).

The use of L-dofa in Parkinsonism reduces primarily hypokinesia and rigidity, to a lesser extent and later diminish tremor, dysphagia, salivation. It is established that the therapeutic effect is achieved in 50 - 60% of patients. In others, the effect is little pronounced, the dose of the drug can not be increased because of side effects.

Assign the drug for Parkinson's disease and symptomatic (postencephalitic, atherosclerotic, toxic) Parkinsonism. There are indications of the effectiveness of the drug in hereditary extrapyramidal diseases characterized by akinetorhidic syndrome. The efficacy of L-dofa in the treatment of deforming muscular dystonia has also been found. There are data on the treatment of L-dofa reactive stuporosis (especially in patients with reduced excretion of dopamine).

As a corrector for the phenomena of parkinsonism caused by neuroleptics, L-dofa is not prescribed.