Hammerstad J P, Woodward W R, Nutt J G, Gancher S T, Block G A, Cyhan G
Department of Neurology, Oregon Health Sciences University, Portland 97201, USA.
Clin Neuropharmacol. 1994 Oct;17(5):429-34. doi: 10.1097/00002826-199410000-00005.
The pharmacokinetics of the clinically determined optimal dose of controlled release levodopa/carbidopa 25/100 (Sinemet CR 25/100) after 12 weeks of therapy was studied in nine parkinsonian patients without prior exposure to levodopa. The pharmacokinetics of single oral doses of controlled release levodopa/carbidopa 25/100 and 50/200 were also compared. As predicted from the plasma half-life (1.7 +/- 0.3 h) and confirmed by morning trough levels, levodopa did not accumulate when controlled released levodopa/carbidopa 25/100 was administered twice daily. The absorption and bioavailability of CR 25/100 are minimally greater than CR 50/200. Controlled released levodopa/carbidopa 25/100 levodopa plasma levels peak slightly faster than controlled release levodopa/carbidopa 50/200.
在9名未曾使用过左旋多巴的帕金森病患者中，研究了治疗12周后临床确定的控释左旋多巴/卡比多巴25/100（息宁控释片25/100）最佳剂量的药代动力学。还比较了单次口服控释左旋多巴/卡比多巴25/100和50/200剂量的药代动力学。正如根据血浆半衰期（1.7±0.3小时）所预测并经早晨谷浓度证实的那样，当每日两次给予控释左旋多巴/卡比多巴25/100时，左旋多巴不会蓄积。控释片25/100的吸收和生物利用度略高于控释片50/200。控释左旋多巴/卡比多巴25/100的左旋多巴血浆水平达到峰值的速度比控释左旋多巴/卡比多巴50/200略快。
