Sinemet CR improves the signs of Parkinson’s disease. Parkinson’s disease is a long-term illness where:•you become slow and unsteady•your muscles feel stiff•you may develop shaking or trembling (called ‘tremor’). If not treated Parkinson’s disease can make it hard for you to continue your normal daily activities. Sinemet CR contains two different medicines called: levodopa and carbidopa. •levodopa turns into a material called ‘dopamine’ in your brain. The dopamine helps to improve the signs of your Parkinson’s disease. •carbidopa belongs to a group of medicines called ‘aromatic amino acid decarboxylase inhibitors’. It helps levodopa work more effectively by slowing the speed at which levodopa is broken down in your body.