Effects of steady-state bupropion on the pharmacokinetics of lamotrigine in healthy subjects

Study Objective. To evaluate the effect of steady-state bupropion SR sustained-release (BUP) on the pharmacokinetics of a single 100-mg dose of lamotrigine (LTG). Design, Randomized, open-label, two-way crossover study. Setting. Clinical Studies Ltd., Fort Lauderdale, Florida. Patients. Twelve healthy subjects. Intervention. Treatment A: LTG 100 mg with steady-state BUP 150 mg twice/day; treatment B: LTG 100 mg. Measurements and Main Results. The pharmacokinetics of LTG were determined by noncompartmental methods using plasma and urine concentrations. Geometric least squares mean ratios and 90% confidence intervals were calculated for treatment comparison. Safety assessments included clinical laboratory tests, vital signs, and adverse events monitoring. Pharmacokinetic parameters of LTG were not significantly different between treatments. Five subjects experienced seven mild, potentially drug-related adverse events (insomnia [2]; nausea, headache, facial pain, fatigue, and depression [1 each]) that resolved spontaneously. Conclusion. Steady-state BUP caused no clinically relevant changes in the pharmacokinetics of a single dose of LTG.