This medication is used to treat a certain inherited disorder (Wilson's disease). This disorder causes too much copper to build up in the liver, brain, and other parts of the body. Trientine works by binding to copper, which helps your body get rid of extra copper. This can decrease symptoms such as problems with speech/swallowing/coordination, tiredness, lack of appetite, abdominal pain, yellowing eyes/skin, fluid buildup in the legs/abdomen, uncontrolled movements, or muscle stiffness.