Portland VA Medical Center Parkinson Disease Research, Education and Clinical Center, Portland, Oregon, USA.
Mov Disord. 2012 May;27(6):750-3. doi: 10.1002/mds.24998. Epub 2012 Apr 16.
Recommended doses of carbidopa are 75-200 mg/day. Higher doses could inhibit brain aromatic amino-acid decarboxylase and reduce clinical effects. We compared 4-week outpatient treatments with carbidopa (75 and 450 mg/day) administered with L-dopa on the subjects' normal schedule. After each treatment phase, subjects had two 2-hour L-dopa infusions. The first infusion examined the effects of carbidopa doses administered the preceding 4 weeks, and the second infusion determined the acute effects of the two dosages of carbidopa. The antiparkinsonian effects and L-dopa and carbidopa plasma concentrations were monitored during the infusions. Twelve subjects completed the study. Carbidopa concentrations were eight times higher after the high-carbidopa phase. Area under the curve (AUC) for clinical ratings did not differ for the four L-dopa infusions, although AUC for plasma L-dopa was modestly increased with 450 mg of carbidopa. Nine subjects reported that the high-carbidopa outpatient phase was associated with greater response to L-dopa. Doses of 450 mg/day of carbidopa did not reduce the responses to L-dopa infusion, extending the safe range of carbidopa to 450 mg/day.
卡比多巴的推荐剂量为 75-200mg/天。较高的剂量可能会抑制大脑芳香族氨基酸脱羧酶并降低临床效果。我们比较了卡比多巴（75 和 450mg/天）与左旋多巴在患者正常时间表上的 4 周门诊治疗。在每个治疗阶段后，患者接受两次 2 小时的左旋多巴输注。第一次输注检查了前 4 周给予的卡比多巴剂量的效果，第二次输注确定了两种剂量的卡比多巴的急性效果。在输注过程中监测抗帕金森病效果和左旋多巴和卡比多巴的血浆浓度。12 名受试者完成了这项研究。高卡比多巴阶段后，卡比多巴浓度高出 8 倍。尽管血浆左旋多巴的 AUC 略有增加，但 4 种左旋多巴输注的临床评分 AUC 并无差异。9 名受试者报告说，高卡比多巴门诊阶段与左旋多巴反应更大有关。每天 450mg 的卡比多巴剂量并未降低对左旋多巴输注的反应，从而将卡比多巴的安全范围扩展到每天 450mg。
