Determination of tetrahydropapaveroline in the urine of parkinsonian patients receiving L-dopa-carbidopa (Sinemet) therapy by high-performance liquid chromatography

Abstract

Tetrahydropapaveroline (THP) concentrations were measured in the urine of Parkinsonian patients receiving L-dopa-carbidopa (Sinemet) therapy, using a method that employs a separation scheme that selectively isolates THP from urine and utilizes the Pictet-Spengler condensation of THP with formaldehyde combined with high-performance liquid chromatography for identification and determination. The mean (+/- S.D.) recoveries of THP from normal urine with 0.2 pmol/ml added and from Parkinsonian patients' urines with 0.5 pmol/ml added were 48.6 +/- 5.7 and 44.6 +/- 3.1%, respectively. Three Parkinsonian patients who were receiving either 250, 750 or 1000 mg of L-dopa (as Sinemet) daily had 24-h urinary THP excretion levels of 989, 1017 and 1600 pmol, respectively.