Table 1.
Pharmacokinetic parameters (mean ± standard deviation) of levodopa, carbidopa, and 3-O-methyldopa after administration of oral levodopa–carbidopa (10:1 levodopa:carbidopa ratio) tablets and jejunal infusion of levodopa–carbidopa intestinal gel (4:1 levodopa:carbidopa ratio) in Japanese subjects with advanced Parkinson’s disease
| Pharmacokinetic parameters | LC-oral tablets (n = 5) | LCIG infusion (n = 5) | ||||
|---|---|---|---|---|---|---|
| Levodopa | Carbidopa | 3-O-methyldopa | Levodopa | Carbidopa | 3-O-methyldopa | |
| Total study drug daily dosea (mg) | 1230 ± 246 | 123 ± 25 | 1370 ± 353 | 342 ± 88 | ||
| t max (h) | 3.0 ± 3.5 | 7.8 ± 2.8 | 11 ± 0.76 | 1.0 ± 0.50 | 4.5 ± 4.2 | 11 ± 0.79 |
| C max (µg/mL) | 5.96 ± 0.768 | 0.128 ± 0.025 | 9.27 ± 2.17 | 4.38 ± 1.15 | 0.273 ± 0.066 | 11.7 ± 1.25 |
| C avg (µg/mL) | 2.37 ± 0.257 | 0.079 ± 0.015 | 7.36 ± 1.93 | 2.87 ± 0.663 | 0.172 ± 0.044 | 9.80 ± 1.23 |
| AUC12 (µg·h/mL) | 28.4 ± 3.08 | 0.943 ± 0.177 | 88.3 ± 23.1 | 34.4 ± 7.95 | 2.07 ± 0.522 | 118 ± 14.7 |
| AUC16 (µg·h/mL) | 46.7 ± 10.7 | 2.80 ± 0.666 | 165 ± 21.2 | |||
| C min (2–12 h) (µg/mL) | 0.734 ± 0.425 | 0.050 ± 0.017 | 5.72 ± 1.53 | 2.38 ± 0.770 | 0.130 ± 0.035 | 8.14 ± 0.936 |
| Degree of fluctuation (2–12 h)b | 2.1 ± 0.59 | 0.97 ± 0.20 | 0.48 ± 0.10 | 0.38 ± 0.16 | 0.78 ± 0.25 | 0.35 ± 0.07 |
| M/P (AUC12) | 3.11 ± 0.71 | 3.53 ± 0.70 | ||||
AUC x area under the plasma concentration–time curve from time zero to x h, C avg average plasma concentration, C max maximum observed plasma concentration, C min minimum observed plasma concentration, LCIG levodopa–carbidopa intestinal gel, LC-oral oral levodopa–carbidopa, M/P ratio of metabolite (3-O-methyldopa) to parent (levodopa), t max time to C max
aTotal dose between hours 0 and 16 on the day of pharmacokinetic assessment (Day −1 for LC-oral tablets, Day 21 for LCIG)
bDegree of fluctuation calculated as (C max–C min)/C avg