When you're dealing with someone who's really taxing you at work, the best thing you can do for yourself is to ignore them.
According to a study in the Journal of Social and Personal Relationships, ignoring nasty people is the most effective way of quieting them rather than talking to them or trying to persuade them. Not only does it work better, but you'll also suffer less negative effects from dealing with them. The people in the study who engaged in discussions with offensive people did poorly on aptitude tests compared to the people who just ignored the nastiness. Of course, it's different in every situation, but for the most part, trying not to react to an obnoxious person may be healthier than stewing in anger.