A 10-year nationwide multicenter prospective study on the long-term efficacy of
bromocriptine for
Parkinson's disease is reported. Six patients remained on
bromocriptine monotherapy for 10 years, while 22 patients achieved good disease control with
bromocriptine plus
levodopa (added during the course of the study). In the 6 patients on
bromocriptine alone, the disease remained in Hoehn and Yahr stage I or II for 10 years. In the other 22 patients on
bromocriptine plus
levodopa therapy,
disease progression was very slow for 7-8 years. None of the 6 patients remaining on
bromocriptine monotherapy experienced adverse reactions like the wearing-off phenomenon,
dyskinesia, or the on-off phenomenon. Among the 22 patients who started
levodopa therapy during the course of the study, these adverse reactions to
levodopa were infrequent (10, 3, and 3 patients, respectively). Thus, early introduction and long continuation of
bromocriptine therapy with restricted concomitant use of
levodopa may have led to very slow
disease progression and the suppression of adverse reactions. Although the patients who could be maintained long-term on
bromocriptine monotherapy might represent a population who have very slowly progressive disease, their adequate disease control and the low incidence of adverse reactions in the patients who later started concomitant
levodopa suggest that the unwanted effects of
levodopa may be reduced by early and sustained treatment with
bromocriptine. Introduction of
bromocriptine monotherapy at an early stage of
Parkinson's disease or with restricted use of additional
levodopa therapy to
bromocriptine when necessary may be a useful strategy for achieving adequate and sustained disease control.