Your impulsiveness sounds almost more linked to aggression/irritability than presenting itself as impulsiveness. I completely understand. (though, do tell me if I am not on the right path)

I get irritable to the high heavens and therefore impulsively swear, yell or slam my fist down. It's this feeling within that makes me need to lash out, not consciously aware of my decision to string some curse words together until I have said it, or slammed my fist down and broken something.

Mood stabilizers, according to an article on medscape.org , prove effective- lithium shows better results than the placebo and lamotrigine also effective.

Clonidine, a blood pressure medication, is used off-label for impulsiveness.