The invention relates to oxyimino compounds of (Formula I), and pharmaceutically acceptable salts, prodrugs and solvates thereof, wherein: Y is CO or SOm; Z is hydrogen, each optionally substituted lower alkyl, lower alkenyl, aryl, heterocyclyl etc. R1 and R2 are each independently hydrogen, each optionally substituted lower alkyl, lower alkenyl, cycloalkyl, aryl, heterocyclyl etc., each X is independently ═O, optionally substituted lower alkyl, cyano, nitro etc., m is 1 or 2, p is O, 1 or 2 and q is O or 1. The invention is also directed to the use compounds of Formula I to treat, prevent or ameliorate a disorder responsive to the blockade of calcium channels, and particularly N-type calcium channels. Compounds of the present invention are especially useful for treating pain.