Pharmacokinetic-pharmacodynamic Interaction Between BIA 3-202 and Levodopa/Benserazide

The purpose of this study is to determine the effect of three single oral doses of nebicapone (50 mg, 100 mg and 200 mg) on the levodopa pharmacokinetics when administered in combination with a single-dose of controlled release levodopa 100 mg/benserazide 25 mg (Madopar® HBS 125).

STUDY DESIGN AND METHODOLOGY: Single centre, double-blind, randomised, placebo-controlled, 4-way crossover study with 4 single-dose treatment periods. The washout period between doses was 5 days or more. Screening: Subjects were screened for eligibility within 28 and 7 days before first admission. The screening consisted of: medical history; physical examination, vital signs; complete neurological examination; 12-lead ECG; haematology, coagulation, plasma biochemistry and urinalysis tests; HIV, hepatitis B and hepatitis C serology; drugs of abuse and alcohol screen; urine pregnancy test in women of childbearing potential; and review of the selection criteria. Treatment periods: In each treatment period, eligible subjects were admitted to the UFH on the day prior to receiving the study medication for: vital signs; medical history and physical examination updates; 12-lead ECG; haematology and plasma biochemistry; drugs of abuse and alcohol screen; and urine pregnancy test in women of childbearing potential. On first admission, subjects had a review of the selection criteria and were randomly assigned to one of the treatment sequences. On the morning of the dosing day, subjects received a dose of nebicapone/placebo concomitantly with a dose of Madopar® HBS 125 in fasting conditions (at least 8 hours) and remained in the UFH until at least 24 h post-dose; then, they left and returned for the next period or the follow-up visit. At given time-points between pre-dose and discharge, subjects were submitted to vital signs recording, brief neurological examination, 12-lead ECG, and blood sampling for plasma drug determination and erythrocyte S-COMT activity assay. At discharge, vital signs and ECG were recorded, and haematology and plasma biochemistry tests were performed. Blood samples (7 mL) for the determination of plasma concentration of levodopa, 3-O-methyldopa (3-OMD) and nebicapone, and for the assay of the erythrocyte S-COMT activity were taken at the following times: pre-dose, ½, 1, 1½, 2, 3, 4, 6, 8, 12, 16 and 24 h post-dose. Follow-up: A follow-up visit occurred approximately 7-10 days after discharge of last treatment period or early discontinuation for: medical history and physical examination updates; vital signs; 12-lead ECG; haematology, plasma biochemistry and urinalysis tests; and pregnancy test in women of childbearing potential.