Robertson, D.R., Wood, N.D., Everest, H., Monks, K., Waller, D.G., Renwick, A.G. and George, C.F. (1989) The Effect of Age on the Pharmacokinetics of Levodopa Administered Alone and in the Presence of Carbidopa. British Journal of Clinical Pharmacology, 28, 61-69.
https://doi.org/10.1111/j.1365-2125.1989.tb03506.x

has been cited by the following article:

• TITLE: Is Levodopa Pharmacokinetics in Patients with Parkinson’s Disease Depending on Gastric Emptying?

  AUTHORS: Maria Nord, Anita Kullman, Ulf Hannestad, Nil Dizdar

  KEYWORDS: Parkinson Disease, Levodopa, Gastric Emptying, Continuous Dopaminergic Stimulation, Microdialysis

  JOURNAL NAME: Advances in Parkinson's Disease, Vol.6 No.1, February 6, 2017

  ABSTRACT: Levodopa uptake from the gastrointestinal tract in patients with Parkinson’s disease (PD) can be affected by delayed gastric emptying (GE). This might lead to fluctuating levodopa levels resulting in increased motor fluctuations. Continuous dopaminergic stimulation (CDS) improves motor fluctuations and could be a result of smoothening in levodopa uptake. In this study we wanted to study the levodopa pharmacokinetics peripherally in PD patients with motor fluctuations and investigate the relation between levodopa uptake and GE and the effect of CDS. PD patients with wearing off (group 1) and on-off syndrome (group 2) were included. Breath tests were performed to evaluate the half time (T1/2) of GE. Concomitantly 1 tablet of Madopark® was given and the levodopa concentrations in blood and subcutaneous (SC) tissue were analyzed for both groups. Group 2 was then given a 10-d continuous intravenous levodopa treatment and the tests were repeated. Higher levels of levodopa in group 1 compared to group 2 in blood (p = 0.014) were seen. The GE was delayed in both group 1 (p