Low-dose lamotrigine co-administration decreases quetiapine plasma concentrations: Effect of UGT2B7-161C>T polymorphism in Japanese patients with depression

Key Points

• To investigate the effect of low-dose lamotrigine on quetiapine plasma concentrations and the role of the UGT2B7-161C>T polymorphism in Japanese patients with depression.
• Participants included Japanese patients diagnosed with depression.
• Low-dose lamotrigine was co-administered with quetiapine.
• Plasma concentrations of quetiapine were measured and analyzed against UGT2B7 genotype variations.
• Low-dose lamotrigine significantly decreased quetiapine plasma concentrations.
• The effect varied based on the UGT2B7-161C>T genotype.
• Certain genotypes showed a more pronounced reduction in quetiapine levels.