Are you talking the rash or the plant?
The rash... look for technu cleanser and wash with it before you get the rash and as soon as possible after. If you get the oil off before it binds with your skin you may not get poison ivy. Technu has been a life saver for me. I walked through poison ivy on a field trip a few weeks ago. I went home, stripped off with clothing going on a towel, washed my shoes in technu, washed me in technu, did the laundry. I have no rash. Yea!
Now to get rid of the plant. I use Roundup. I have had success with the regular one as well as the one for poison ivy. I spray it on the ivy. In few days it is dead. Unfortunately, this does not dissolve the oils that cause the rash. They will be on neighboring plants and trees for eons unless I somehow use the Technu on them. Roundup will not poison the ground and kill trees and the like when used in a typical spray the leaves manner. It only kills what it touches. This protects the rest of your property.