PURPOSE: The use of a neuronal sodium channel antagonist is provided. The composition is effective in the prevention, amelioration or control of external parasites on a human or animal by the administration of a prophylactically, therapeutically or pharmaceutically effective amount thereof to the human or animal in need thereof. CONSTITUTION: The neuronal sodium channel antagonist is a compound of formula 1, 2 or 3 or its stereoisomer. In formula, A is CR4R5 or NR6, W is 0 or S, X,Y,Z,X',Y' and Z' are each independently H; halogen; OH;CN;NO2; C1-6 alkyl optionally substituted with one or more halogens, C1-3 alkoxy, C1-3 haloalkoxy, C3-6 cycloalkyl, C2-6 alkenyloxy or sulfonyloxy groups; C1-6 alkoxy optionally substituted with one or more halogens, C1-3 alkoxy or C3-6 cycloalkyl groups; C1-6 alkoxycarbonyl optionally substituted with one or more halogens, C1-4 alkyl or C1-3 alkoxy groups, C3-6 cycloalkylcarbonyloxy, phenyl; aminocarbonyloxy optionally substituted with one or more C1-3 alkyl groups; C1-6 alkoxycarbonyloxy; C1-6 alkoxycarbonyloxy; C1-6 alkylsulfonyloxy; C2-6 alkenyl; or NR12R13, the remaining is defined in the specification. A composition for the control of ectoparasites in homeothermic animals contains about 20% w/v of a neuronal sodium channel antagonist of formula 1a, about 10% w/v of amitraz of diethyl toluamide as a pharmaceutically acceptable carrier, about 20% by weight of isopropyl myristate and about 10% by weight of cineol.
Use of neuronal sodium channel antagonists for the control of ectoparasites in homeothermic animals