The combination drug Cinemet is used to treat symptoms of Parkinson's disease or Parkinson's-like symptoms (such as shakiness, stiffness, and difficulty moving). Parkinson's disease is thought to be caused by too little of a naturally occurring substance (dopamine) in the brain. Cinemet converts to dopamine in the brain, which helps It controls movement and prevents breakdown in the bloodstream, so more of the drug can enter the brain. The drug can also cause symptoms such as nausea and vomiting.