A single-blind cross over study investigating the efficacy of standard and controlled release levodopa in combination with entacapone in the treatment of end-of-dose effect in people with Parkinson’s disease

Abstract

ObjectiveTo determine the efficacy of standard levodopa combined with controlled release levodopa and entacapone in controlling end-of-dose symptoms in Parkinson’s disease. MethodsA single-blind cross over design was used to compare the duration of action for three pharmacological combinations: standard levodopa (L/DDC); standard levodopa combined with entacapone (L/DDC/E); and standard levodopa combined with controlled release levodopa (CR) and entacapone (L/DDC/CR/E). Thirty two participants with wearing-off symptoms and inadequate symptom control with L/DDC/E had their optimum dose of L/DDC determined at base line. Entacapone was added to the optimal L/DDC dose and duration of action determined. Levodopa CR dosage was adjusted to match the optimal L/DDC dose for each participant. All participants were then trialed on L/DDC/CR/E and duration of response calculated. Timed Up and Go (TUG) times and magnitude of extra movements were recorded hourly throughout the day over several days to determine the optimum interval between doses for each combination. The UPDRS (Sections 2 and 3), PDQ39 and fatigue scale, the PDF-16, were recorded at base line and when dosage intervals had stabilized on L/DDC/CR/E. ResultsDuration of response was greatest with L/DDC/CR/E compared to L/DDC/E (p < 0.001) and number of daily doses were less on L/DDC/CR/E compared to L/DDC/E (p < 0.001). UPDRS, PDQ39 and fatigue scores also improved on L/DDC/CR/E compared to L/DDC (p < 0.001). Dyskinesia increased on L/DDC/CR/E (p = 0.001) however magnitude was mild. ConclusionCombining standard levodopa and levodopa CR preparations with entacapone is an additional treatment strategy to manage motor fluctuations in advanced PD.