FIGURE 4.
Tonic block and blocking kinetics of lamotrigine and representative class Ia, Ib, and Ic compounds. Values are mean ± SEM. (a) Tonic block of NaV1.5 by mexiletine, lamotrigine, quinidine, and flecainide. Percent inhibitions are 9.2 ± 1.5 (n = 5), 2.6 ± 2.1 (n = 8), 26.8 ± 1.4 (n = 6), 6.7 ± 1.2 (n = 7), and 1.6 ± 1.2 (n = 6) for mexiletine, lamotrigine (25 μM), lamotrigine (280 μM), quinidine, and flecainide, respectively. (b) NaV1.5 blocking kinetics (τ on) of mexiletine, lamotrigine, quinidine, and flecainide (Table S2). (c) NaV1.5 blocking kinetics (τ off) of mexiletine, lamotrigine, quinidine, and flecainide (Table S2). The 95% confidence intervals are graphed as dotted lines. (d) Expanded view of X‐axis (0–10 s) from panel c.