Contin M, Riva R, Martinelli P, Procaccianti G, Baruzzi A
Institute of Neurology, University of Bologna, Italy.
Clin Neuropharmacol. 1989 Feb;12(1):75-81. doi: 10.1097/00002826-198902000-00010.
The effect of a 2.5-fold increase in daily carbidopa intake on the bioavailability of levodopa was studied in six patients with Parkinson's disease on a low chronic regimen of carbidopa-levodopa (Sinemet) at the fixed ratio of 1:10. The extent of levodopa absorption, expressed as the area under the 11-h plasma levodopa concentration-time curve (AUC0-11 h), was not enhanced by the higher carbidopa dose. A significant increase in the AUC was found for the levodopa metabolite 3-O-methyldopa at the higher carbidopa intake. Clinical performances of individual patients were identical with both carbidopa-levodopa ratios. From these data, an adequate inhibition of peripheral decarboxylation and hence a good bioavailability of levodopa may be expected in patients taking low doses of carbidopa-levodopa, using currently available commercial preparations.
在六名帕金森病患者中，研究了将卡比多巴的每日摄入量增加2.5倍对左旋多巴生物利用度的影响。这些患者正在接受低剂量的卡比多巴-左旋多巴（息宁）慢性治疗，固定比例为1:10。以11小时血浆左旋多巴浓度-时间曲线下面积（AUC0-11 h）表示的左旋多巴吸收程度，并未因较高的卡比多巴剂量而提高。在较高的卡比多巴摄入量下，左旋多巴代谢产物3-O-甲基多巴的AUC显著增加。两种卡比多巴-左旋多巴比例下，个体患者的临床表现相同。从这些数据来看，使用目前市售制剂，服用低剂量卡比多巴-左旋多巴的患者可能会有外周脱羧的充分抑制，从而有良好的左旋多巴生物利用度。
