Night-time bioavailability of levodopa/carbidopa/entacapone is higher compared to controlled-release levodopa/carbidopa.
ABSTRACT Controlled-release levodopa/carbidopa (CR-LC) is often used to provide prolonged control of night-time motor symptoms in patients with Parkinson's disease (PD). Levodopa/carbidopa/entacapone (LCE) provides higher bioavailability of levodopa compared with levodopa/carbidopa formulations and has been shown to be effective in PD patients with wearing-off symptoms. The aim of this study was to compare the bioavailability of levodopa after a single evening dose (administered at 10 p.m.) of LCE 200 or CR-LC 200.
This was an open-label, randomized, crossover study in healthy subjects. The main pharmacokinetic (PK) parameters were AUC, Cmax, C6h and t1/2 of levodopa.
A single evening dose of LCE 200 was associated with significantly better bioavailability compared with CR-LC 200. In line with increased bioavailability of levodopa, LCE 200 induced more nausea.
The results of this study demonstrate that a single bedtime dose of LCE 200 provides higher bioavailability of levodopa compared to CR-LC 200.
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ABSTRACT: Levodopa has been the mainstay of Parkinson's disease (PD) therapy for over 40 years, with its efficacy surpassing that of other antiparkinsonian medications. As such, most PD patients eventually require levodopa-based therapy during the course of the disease. However, despite its proven efficacy, long-term levodopa therapy is associated with motor complications, with wearing-off being the most prevalent. Wearing-off occurs, in part, as a result of the short half-life of levodopa, which leads to fluctuations in plasma levodopa levels. A pharmacokinetic profile characterized by a higher trough value of levodopa can be achieved by combining levodopa/carbidopa with entacapone, which inhibits the peripheral breakdown of levodopa, resulting in higher plasma levodopa levels. Here, we review the limitations of conventional levodopa and the clinical data for levodopa/carbidopa/entacapone in treating patients with wearing-off.Expert Review of Neurotherapeutics 02/2012; 12(2):119-31. · 2.96 Impact Factor
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ABSTRACT: Parkinson disease (PD) is a progressive, disabling, neurodegenerative disorder characterized by both motor and nonmotor symptoms. Monoamine oxidase B inhibitors, dopamine agonists, N-methyl-D-aspartate antagonists and levodopa (LD), with its various formulations and administration modes, mainly improve the motor symptoms in PD, which are thought to be related to decreased dopamine levels in the brain. Of these therapeutic drug options, LD represents the most effective and best tolerated compound when it is administered several times a day. Pharmacokinetic trials of oral LD/dopa decarboxylase inhibitor (DDCI) formulations with and without the catechol-O-methyltransferase inhibitor, entacapone, showed that repeated administration with entacapone causes an increase in both the maximum concentration (Cmax) and time to Cmax (Tmax) of LD. In addition, gastrointestinal motility may also impact plasma LD behavior. These peripheral components of LD metabolism contribute to the onset of motor complications, which are predominantly associated with LD/DDCI owing to its short plasma half-life. The increase in Tmax is related to a slower increase in plasma LD concentrations after repeated LD/DDCI intake, which may also increase the risk of wearing off. An elevation in Cmax after reiterated LD intake increases the risk of peak-dose dyskinesia. Therefore, it may be useful to start with higher doses of LD formulations in the morning and then to titrate with different LD doses during the day according to the individual patient's motor behavior, which is particularly characterized by the onset of motor complications, such as off periods and dyskinesia, in more advanced stages of PD.Clinical neuropharmacology 36(3):84-91. · 2.35 Impact Factor