tokens: Recently , we reported that fluvoxamine , but not paroxetine , significantly ameliorated cognitive deficits in mice after repeated phencyclidine administration , and that the effects of fluvoxamine were antagonized by co - administration of the selective sigma - 1 receptor antagonist NE - 100 [ 20 ] , suggesting that sigma - 1 receptors are involved in the mechanism of action of fluvoxamine [ 9 ] .