Night-time bioavailability of levodopa/carbidopa/entacapone is higher compared to controlled-release levodopa/carbidopa

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.