A multicenter Italian randomised study on early treatment of Parkinson disease: comparison of 1-dopa, 1-deprenyl and dopaminoagonists. Study design and short term results

Efficacy and safety of selegiline for the treatment of Parkinson's disease: A systematic review and meta-analysis

Background

Drug efficacy generally varies with different durations. There is no systematic review analyzing the effect of selegiline for Parkinson's disease (PD) on different treatment duration. This study aims to analyze how the efficacy and safety of selegiline changes for PD over time.

Methods

PubMed, the Cochrane Library, Embase, China National Knowledge Infrastructure and Wanfang Database were systematically retrieved for randomized controlled trials (RCTs) and observational studies of selegiline for PD. The search period was from inception to January 18th, 2022. The efficacy outcomes were measured by the mean change from baseline in the total and sub Unified Parkinson's Disease Rating Scale (UPDRS), Hamilton Depression Rating Scale (HAMD) and Webster Rating Scale (WRS) scores. The safety outcomes were measured by the proportion of participants having any adverse events overall and that in different system organ classes.

Results

Among the 3,786 studies obtained, 27 RCTs and 11 observational studies met the inclusion criteria. Twenty-three studies reported an outcome which was also reported in at least one other study, and were included in meta-analyses. Compared with placebo, selegiline was found with a stronger reduction of total UPDRS score with increasing treatment duration [mean difference and 95% CIs in 1 month: -3.56 (-6.67, -0.45); 3 months: -3.32 (-3.75, -2.89); 6 months: -7.46 (-12.60, -2.32); 12 months: -5.07 (-6.74, -3.41); 48 months: -8.78 (-13.75, -3.80); 60 months: -11.06 (-16.19, -5.94)]. A similar trend was also found from the point estimates in UPDRS I, II, III, HAMD and WRS score. The results of observational studies on efficacy were not entirely consistent. As for safety, compared with placebo, selegiline had higher risk of incurring any adverse events [rate: 54.7% vs. 62.1%; odd ratio and 95% CIs: 1.58 (1.02, 2.44)], with the excess adverse events mainly manifested as neuropsychiatric disorders [26.7% vs. 31.6%; 1.36 (1.06, 1.75)] and no significant change over time. The statistically difference in overall adverse event between selegiline and active controls was not found.

Conclusion

Selegiline was effective in improving total UPDRS score with increasing treatment duration, and had a higher risk of incurring adverse events, especially the adverse events in the neuropsychiatric system.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: PROSPERO CRD42021233145.

Comparative efficacy and acceptability of drug treatments for Parkinson's disease with depression: A systematic review with network meta-analysis

Depressive symptom is the prevailing non-motor symptom of Parkinson's disease (PD). Drug treatments for depressed PD (dPD) can mitigate the symptoms of patients. However, the results are discordant and need further analysis. This systematic review with network meta-analysis aims to evaluate the drug treatments for dPD. We included double-blind, randomized controlled trials to compare antidepressants with placebo or other antidepressants in dPD. We performed traditional pairwise analysis and network meta-analysis concerning the efficacy, acceptability, depression score, and adverse effect. The surface under the cumulative ranking curve was to assess the ranking probabilities of the enrolled agents. We enrolled 62 studies, including 12,353 subjects, to analyze these estimates. For the traditional pairwise meta-analysis, dopamine agonist (DOP; OR = 2.20 [95% CI, 1.46 to 3.33]) and selective serotonin reuptake inhibitor (SSRI; OR = 2.30 [95% CI, 1.15 to 4.60]) were observed to improve the efficacy compared with placebo. For network meta-analysis, DOP was observed to improve the efficacy compared with placebo (OR = -0.84 [95% CI, -1.20 to -0.48]). Both direct and indirect evidence showed that several treatments, e.g., DOP, monoamine-oxidase inhibitor, serotonin-norepinephrine reuptake inhibitors, SSRI, and tricyclic antidepressants, significantly improved depressive symptoms. DOP and SSRI had good efficacy and improved symptoms considerably in dPD, but the adverse effect of these agents was needed to follow closely.

Efficacy of antidepressive medication for depression in Parkinson disease: a network meta-analysis

BACKGROUND

Parkinson disease (PD) was considered as the 2nd most prevalent neurodegenerative disorder after Alzheimer disease, while depression is a prevailing nonmotor symptom of PD. Typically used antidepression medication includes tricyclic antidepressants (TCA), selective serotonin reuptake inhibitors (SSRI), serotonin and norepinephrine reuptake inhibitors (SNRI), monoamine-oxidase inhibitors (MAOI), and dopamine agonists (DA). Our study aimed at evaluating the efficacy of antidepressive medications for depression of PD.

METHODS

Web of Science, PubMed, Embase, and the Cochrane library were searched for related articles. Traditional meta-analysis and network meta-analysis (NMA) were performed with outcomes including depression score, UPDRS-II, UPDRS-III, and adverse effects. Surface under the cumulative ranking curve (SUCRA) was also performed to illustrate the rank probabilities of different medications on various outcomes. The consistency of direct and indirect evidence was also assessed by node-splitting method.

RESULTS

Results of traditional pairwise meta-analysis were performed. Concerning depression score, significant improvement was observed in AD, MAOI, SSRI, and SNRI compared with placebo. NMA was performed and more information could be obtained. DA was illustrated to be effective over placebo concerning UPDRS-III, MAOI, and SNRI. DA demonstrated a better prognosis in UPDRS-II scores compared with placebo and MAOI. However, DA and SSRI demonstrated a significant increase in adverse effects compared with placebo. The SUCRA value was calculated to evaluate the ranking probabilities of all medications on investigated outcomes, and the consistency between direct and indirect evidences was assessed by node-splitting method.

CONCLUSION

SSRI had a satisfying efficacy for the depression of PD patients and could improve activities of daily living and motor function of patient but the adverse effects are unneglectable. SNRI are the safest medication with high efficacy for depression as well while other outcomes are relatively poor.

Monoamine oxidase B inhibitors versus other dopaminergic agents in early Parkinson's disease

BACKGROUND

It has been postulated that monoamine oxidase B (MAO-B) inhibitors alter disease progression in Parkinson's disease (PD) but trials have produced conflicting results.

OBJECTIVES

To assess the effectiveness and safety of long-term use of MAO-B inhibitors compared with other dopaminergic agents in early PD.

SEARCH STRATEGY

We searched several electronic databases including: the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2009), MEDLINE (January 1950 to February 2009) and EMBASE (January 1980 to February 2009). We also handsearched neurology and movement disorders conference proceedings, checked reference lists of relevant studies and contacted other researchers.

SELECTION CRITERIA

We included all randomised controlled trials that compared a MAO-B inhibitor with other dopaminergic agents (presently levodopa or dopamine agonists) in patients with early PD, where treatment and follow up lasted at least one year.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed the methodological quality, and extracted the data. Additional data were provided by the original authors. Random-effects models were used to analyse results, where appropriate.

MAIN RESULTS

Only two eligible trials were included (593 patients), both of reasonable quality although one was unblinded. Both trials compared selegiline with a dopamine agonist, whilst one also compared selegiline with levodopa. MAO-B inhibitors were not associated with a significant increase or decrease in deaths compared with levodopa (odds ratio (OR) 0.96; 95% confidence interval (CI) 0.52 to 1.76) or dopamine agonists (OR 1.30; 95% CI 0.69 to 2.45). Those receiving MAO-B inhibitors were more likely to require add-on therapy during follow-up than those receiving levodopa (OR 12.02; 95% CI 6.78 to 21.31) or dopamine agonist (OR 2.00; 95% CI 1.05 to 3.81). There was a reduction in motor fluctuations with MAO-B inhibitors compared with levodopa (OR 0.55; 95% CI 0.32 to 0.94) but not dopamine agonists (OR 1.15; 95% CI 0.65 to 2.05). Withdrawals due to adverse events were less common with MAO-B inhibitors than with dopamine agonists (OR 0.11; 95% CI 0.01 to 0.99).

AUTHORS' CONCLUSIONS

MAO-B inhibitors are one option for the early treatment of PD although they have weaker symptomatic effects than levodopa and dopamine agonists. They may reduce the rate of motor fluctuations compared with initial levodopa therapy and may have fewer significant adverse effects than the older agonists but data are too few to provide reliable conclusions.

Monoamine oxidase B inhibitors for early Parkinson's disease

BACKGROUND

It has been postulated that monoamine oxidase B (MAO-B) inhibitors alter disease progression in Parkinson's disease (PD). Clinical trials have produced conflicting results.

OBJECTIVES

To assess the evidence from randomized controlled trials for the effectiveness and safety of long-term use of MAO-B inhibitors in early PD.

SEARCH STRATEGY

We searched the following electronic databases: Cochrane Central Register of Controlled trials (CENTRAL) (The Cochrane Library Issue 2, 2004), MEDLINE (last searched 18th August 2004) and EMBASE (last searched 18th August 2004). We also handsearched neurology and movement disorders conference proceedings, checked reference lists of relevant studies and contacted other researchers.

SELECTION CRITERIA

We sought to include all unconfounded randomized controlled trials that compared a MAO-B inhibitor with control, in the presence or absence of levodopa or dopamine agonists, in patients with early PD and where treatment and follow up lasted at least one year.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed the methodological quality, and extracted the data. A small amount of additional data was provided by the original authors. Random-effects models were used to analyse results, where appropriate.

MAIN RESULTS

Ten trials were included (a total of 2422 patients), nine using selegiline, one using lazabemide. The methodological quality was reasonable although concealment of allocation was definitely adequate in only four trials. The mean follow up was for 5.8 years. MAO-B inhibitors were not associated with a significant increase in deaths (odds ratio (OR) 1.15; 95% confidence interval (CI) 0.92 to 1.44). They provided small benefits over control in impairment (weighted mean difference (WMD) for change in motor UPDRS score was 3.81 points less with MAO-B inhibitors; 95% CI 2.27 to 5.36) and disability (WMD for change in UPDRS ADL score was 1.50 less; 95% CI 0.48 to 2.53) at one year which, although statistically significant, were not clinically significant. There was a marked levodopa-sparing effect with MAO-B inhibitors which was associated with a significant reduction in motor fluctuations (OR 0.75; 95% CI 0.59 to 0.94) but not dyskinesia (OR 0.97; 95% CI 0.76 to 1.25). The reduction in motor fluctuations was, however, not robust in sensitivity analyses. Although adverse events were generally mild and infrequent, withdrawals due to side-effects were higher (OR 2.36; 95% CI 1.32 to 4.20) with MAO-B inhibitors.

AUTHORS' CONCLUSIONS

MAO-B inhibitors do not appear to delay disease progression but may have a beneficial effect on motor fluctuations. There was no statistically significant effect on deaths although the confidence interval does not exclude a small increase with MAO-B inhibitors. At present we do not feel these drugs can be recommended for routine use in the treatment of early Parkinson's disease but further randomized controlled trials should be carried out to clarify, in particular, their effect on deaths and motor complications.

The abnormality of N30 somatosensory evoked potential in idiopathic Parkinson's disease is unrelated to disease stage or clinical scores and insensitive to dopamine manipulations

We recorded short latency somatosensory evoked potentials (SEPs) to median nerve stimuli in 40 patients affected by idiopathic Parkinson's disease (PD) classified from I to IV on the Hoehn and Yahr disability scale. SEPs were recorded before and after chronic administration of L-Dopa and bromocriptine, before and after acute administration of L-Dopa. Fourteen patients experiencing wearing off and dystonic-dyskinetic disturbances were recorded during the occurrence of these oscillations of their clinical status. Absent or reduced N30 components were found in 32.5% of patients. SEPs were not modified by acute or chronic administration of L-Dopa or bromocriptine or during off and dystonic or dyskinetic conditions. Multiple correlations of N30 with scores of the Unified Parkinson's Disease Rating Scale showed that N30 abnormality did not classify patients with prominent clinical features, nor did it predict the outcome of treatment.