Coadministration of domperidone increases plasma levodopa concentration in patients with Parkinson disease.

Abstract

OBJECTIVES:

The aim of this study was to examine the effects of the peripheral dopamine D2-receptor antagonist, domperidone, on the plasma kinetics of levodopa in patients with Parkinson disease (PD).

METHODS:

In a randomized crossover design, 18 hospitalized patients with PD received a single dose of levodopa/benserazide, 100/25 mg, with or without domperidone, 10 mg, under fasting conditions. Plasma levodopa concentrations were determined up to 3 hours after dose administration.

RESULTS:

Mean ± SEM levodopa maximum plasma concentration (Cmax) (14.1 ± 2.9 vs 9.7 ± 1.6 μmol/L; P < 0.01), plasma concentration at 30 min (C30 min) (13.7 ± 3.0 vs 8.1 ± 2.0 μmol/L; P < 0.01), and area under the plasma concentration-time curve from 0 to 3 hours (AUC0-3 hr) (15.9 ± 3.1 vs 12.1 ± 2.4 μmol/L · hour; P < 0.05) were significantly higher after coadministration of levodopa with domperidone compared to levodopa alone. Thus, domperidone increased levodopa Cmax and AUC0-3 hr by 1.5- and 1.3-fold, respectively. There were no exacerbations of PD by concomitant domperidone administration.

CONCLUSIONS:

The results demonstrate that coadministration of domperidone increased the bioavailability of levodopa. This may be the reason for no exacerbation of PD in concomitant administration of domperidone, a dopamine D2-receptor blocker.

• Authors: Noriko Nishikawa, Masahiro Nagai, Tomoaki Tsujii, Hirotaka Iwaki, Hayato Yabe, Masahiro Nomoto
• Journal: Clinical neuropharmacology (Clin Neuropharmacol) 2012 Jul-Aug Vol. 35 Issue 4 Pg. 182-4 ISSN: 1537-162X [Electronic] United States
• PMID: 22751085 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Dopamine D2 Receptor Antagonists
• Levodopa
• Domperidone

Topics

• Aged
• Biological Availability
• Cross-Over Studies
• Domperidone (administration & dosage, blood)
• Dopamine D2 Receptor Antagonists
• Drug Synergism
• Drug Therapy, Combination
• Female
• Humans
• Levodopa (administration & dosage, blood)
• Male
• Middle Aged
• Parkinson Disease (blood, drug therapy)