Monitoraggio delle concentrazioni sieriche di Lamotrigina: Analisi delle interazioni farmacocinetiche con altri farmaci antiepilettici

The analysis of LTG serum levels in steady-state conditions obtained in 240 adult patients (age range 15-72 yrs) is reported. LTG monatherapy was administered to 27 subjects, while a bitherapy was adminestered to 97 pts (30 pts + VPA, 14 pts + PHT, 38 pts + CBZ, 15 pts + PB/PRI) and LTG politherapy to 116 pts(72 pts + 2 inducing AEDs, 44 pts + 1 ind+VPA). LTG daily doses were higher in subjects treated with inducing AEDs than in those treated with VPA in association, but the corresponding LTG levels were lower than in the former pts. A modest relationship was observed LTG between doses and levels (r = 0,73 in monotherapy) but it was absent during treatment with inducing AEDs. The level/dose ratio varied from 1,3 during monatherapy to 3,1 during association with VPA, while during bi or polytherapy with inducing AEDs changed from 0,6 (+PB/PRI or +CBZ) to 0,4 (+ PHT or + 2 inducing AEDS). From a pharmacokinetic point of view LTG should be administered as single drug or in association with VPA since the association with inducing AEDs leads to low levels.