XE 991 dihydrochloride, a Kv7 (KCNQ) channels blocker, potently inhibits Kv7.1 (KCNQ1), Kv7.2 (KCNQ2), Kv7.2 + Kv7.3 (KCNQ3) channel, and M-current with IC₅₀s of 0.75 µM, 0.71 µM, 0.6 μM, and 0.98 µM, respectively^[1]. IC50 & Target: IC50: 0.75 µM ( Kv7.1 channel), 0.71 µM (Kv7.2 channel), 0.6 µM (Kv7.2 + Kv7.3 channel), 0.98 μM (M-current)^[1] In Vitro: XE 991 dihydrochloride possesses an EC₅₀ of 490 nM for enhancement of [³H]ACh release from rat brain slices, and shows good in vivo potency and duration of action^[2].