Pharmacokinetics of lacosamide and omeprazole coadministration in healthy volunteers: results from a phase I, randomized, crossover trial.

BACKGROUND: The antiepileptic drug lacosamide has a low potential for drug-drug interactions, but is a substrate and moderate inhibitor of the cytochrome P450 (CYP) enzyme CYP2C19.
OBJECTIVE: This phase I, randomized, open-label, two-way crossover trial evaluated the pharmacokinetic effects of lacosamide and omeprazole coadministration.
METHODS: Healthy, White, male volunteers (n = 36) who were not poor metabolizers of CYP2C19 were randomized to treatment A (single-dose 40 mg omeprazole on days 1 and 8 together with 6 days of multiple-dose lacosamide [200-600 mg/day] on days 3-8) and treatment B (single doses of 300 mg lacosamide on days 1 and 8 with 7 days of 40 mg/day omeprazole on days 3-9) in pseudorandom order, separated by a ≥ 7-day washout period. Area under the concentration-time curve (AUC) and peak concentration (C(max)) were the primary pharmacokinetic parameters measured for lacosamide or omeprazole administered alone (reference) or in combination (test). Bioequivalence was determined if the 90 % confidence interval (CI) of the ratio (test/reference) fell within the acceptance range of 0.8-1.25.
RESULTS: The point estimates (90 % CI) of the ratio of omeprazole + lacosamide coadministered versus omeprazole alone for AUC (1.098 [0.996-1.209]) and C(max) (1.105 [0.979-1.247]) fell within the acceptance range for bioequivalence. The point estimates (90 % CI) of the ratio of lacosamide + omeprazole coadministration versus lacosamide alone also fell within the acceptance range for bioequivalence (AUC 1.133 [1.102-1.165]); C(max) 0.996 (0.947-1.047).
CONCLUSION: Steady-state lacosamide did not influence omeprazole single-dose pharmacokinetics, and multiple-dose omeprazole did not influence lacosamide single-dose pharmacokinetics.

RCT Entities:   Population Interventions Outcomes