The paper reports plasma levels of levodopa (LD). its main metabolites [dopamine. dihydroxyphenylacetic acid, homovanillic acid. 3-O-methyldopa (3-0-MD)] and carbidopa in 14 parkinsonian patients first treated with Sinemet and thereafter with Sinemet-CR4. A good relationship was observed between LD plasma levels and pharmacological effects. While the LD area under the curve increased after Sinemet-CR4, the same was not observed with metabolites, except with 3-O-MD. The experiments in volunteer subjects confirmed the increase in 3-O-MD in plasma after Sinemet-CR4. Higher levels were observed also in the CSF with a reduction of LD concentrations. This seems to corroborate the hypothesis of an interference with LD passage through the blood-brain barrier in humans
Plasma levels of levodopa. Its main metabolites and carbidopa after conventional and slow release levodopa-carbidopa treatment in parkinsonian patients.
BARALDO, Massimo;FURLANUT, Mario
1990-01-01
Abstract
The paper reports plasma levels of levodopa (LD). its main metabolites [dopamine. dihydroxyphenylacetic acid, homovanillic acid. 3-O-methyldopa (3-0-MD)] and carbidopa in 14 parkinsonian patients first treated with Sinemet and thereafter with Sinemet-CR4. A good relationship was observed between LD plasma levels and pharmacological effects. While the LD area under the curve increased after Sinemet-CR4, the same was not observed with metabolites, except with 3-O-MD. The experiments in volunteer subjects confirmed the increase in 3-O-MD in plasma after Sinemet-CR4. Higher levels were observed also in the CSF with a reduction of LD concentrations. This seems to corroborate the hypothesis of an interference with LD passage through the blood-brain barrier in humansI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
