Early initiation of Low dose levodopa fails to arrest Parkinson's disease progression: Study

A new study by Henrieke Frequin and colleagues found no differences in the occurrence of motor problems or the course of the disease between individuals with early Parkinson's disease (PD) who started therapy with a low dosage of levodopa at different periods. The findings of this study were published in the journal of Movement Disorders.

The patients were randomized to receive levodopa/carbidopa 300/75 mg daily for 80 weeks (early start) or a placebo for 40 weeks, after which they were given levodopa/carbidopa 300/75 mg daily for 40 weeks (delayed start). This research conducted follow-up visits at 3 and 5 years after baseline. After excluding individuals who did not develop PD 5 years after baseline, this study compared the effect of starting levodopa 40 weeks sooner to placebo on PD progress over 5 years. Using linear regression, this research evaluated the between-group differences in terms of the overall Unified Parkinson's Disease Rating Scale score at three and five years. The study contrasted the levodopa equivalent daily dose, the prevalence of wearing off and the prevalence of dyskinesia.

A total of 321 patients in all completed the five-year visit. At 3 and 5 years, there was no difference in the overall Unified Parkinson's Disease Rating Scale between treatment groups based on the adjusted square root transformation.

At five years, dyskinesia was reported by 46 out of 160 patients in the early-start group and 62 out of 161 patients in the delayed-start group (P = 0.06). Also, there were no appreciable differences in the frequency of wearing off or the daily dosage of levodopa equivalent between the groups.

There was no discernible difference in the course of the disease or the frequency of levodopa-induced motor problems between individuals with early, non-disabling Parkinson's disease (PD) who started the therapy with a low dosage of levodopa 40 weeks sooner vs 40 weeks later throughout the course of the next 5 years.

Overall, these results support that levodopa therapy does not alter the disease course and imply that beginning the medication early does not increase the likelihood of side effects such dyskinesia or wearing off.

Source:

Frequin, H. L., Verschuur, C. V. M., Suwijn, S. R., Boel, J. A., Post, B., Bloem, B. R., van Hilten, J. J., van Laar, T., Tissingh, G., Munts, A. G., Dijk, J. M., Lang, A. E., Dijkgraaf, M. G. W., Hoogland, J., & de Bie, R. M. A. (2024). Long‐Term Follow‐Up of the LEAP Study: Early Versus Delayed Levodopa in Early Parkinson’s Disease. In Movement Disorders (Vol. 39, Issue 6, pp. 975–982). Wiley. https://doi.org/10.1002/mds.29796