Pharmaceutical The Parkinson's disease therapeutics market in 2008 amounted to over $1 billion in the European Union, which includes total sales of carbidopa/levodopa, dopamine agonists, MAO-B inhibitors, COMT inhibitors and anticholinergics used for disease symptom relief. With the introduction of newer dopamine agonists, as well as fresh recommendations and treatment guidelines that call for using dopamine agonists as first-line therapy, the market is experiencing a shift away from the use of carbidopa/levodopa. 9 December 2009