Prescribing Pattern of Anti-Parkinson Drugs in Japan: A Trend Analysis from 2005 to 2010

Objective: Therapeutic options for Parkinson's disease mainly consist of L-dopa and dopamine agonists. However, in Japan, the product labeling of the ergot dopamine agonists, cabergoline and pergolide, was revised in April 2007 due to the risk of developing cardiac valvulopathy. Here, we describe the prescribing trends of anti-Parkinson drugs from 2005 through 2010 in Japan, and examined whether these trends changed after the drug safety measures in 2007. Methods and Patients: We used medical claim data from January 2005 to December 2010 for Parkinson's disease patients older than 30 years who were prescribed anti-Parkinson drugs. We calculated the proportion of patients prescribed each drug for each year, and compared the proportions of first-line drugs prescribed before and after April 2007. We also examined the prescription variations of cabergoline/pergolide users one year before or after April 2007. Results: L-dopa was the most frequently prescribed drug for Parkinson's disease (2005, 58%; 2010, 51%). The proportion of patients prescribed ergot dopamine agonists markedly decreased and non-ergot dopamine agonists increased after 2007. Among first-line drugs, the proportion of non-ergot agents increased after April 2007. Among 54 cabergoline/pergolide users, 24 (44%) discontinued these drugs, nine of whom switched to non-ergot agents. Conclusion: L-dopa was the mainstay of Parkinson's disease treatment between 2005 and 2010 in Japan. There was a decrease in ergot agents and an increase in non-ergot agents prescribed after the regulatory actions in 2007.