Long-term treatment of Parkinson's disease with levodopa and other adjunctive drugs

Demographic and Clinical Characteristics in Different Motor Subtypes of Parkinson's Disease: How Well Do the Findings Fit Within the Framework of Existing Hypotheses?

BACKGROUND AND PURPOSE

This study aimed to investigate risk factors, prodromal signs, and non-motor symptoms (NMSs) across various motor subtypes of Parkinson's disease (PD) and to interpret the findings within the context of existing hypotheses on PD subtypes.

METHODS

A search of the database yielded 300 individuals who satisfied the study's inclusion and exclusion criteria. Among them, 168 patients diagnosed with idiopathic PD underwent a comprehensive evaluation of both motor and non-motor symptoms. The classification of motor subtypes was conducted according to the methodology proposed by Stebbins.

RESULTS

The study population consisted of 59.9% males, with an average age of disease onset at 65.45 years. Among them, 87 (51.8%) were classified as having the tremor-dominant (TD) subtype, 61 (36.3%) had the postural instability and gait disorder (PIGD) subtype, and 20 (11.9%) fell into the intermediate (I) subtype. Significant differences between motor subtypes were observed in age at assessment (p = 0.03), age at onset (p = 0.02), education level (p = 0.015), handedness (p = 0.013), proportion of non-smokers (p = 0.021), cognitive impairment (p = 0.003), and apathy (p = 0.003). Additionally, statistically significant variations were found across different rating scales and questionnaires, including MoCA (p = 0.009), HAM-A (p = 0.008), HAM-D (p = 0.007), H&Y (p = 0.004), SAS (p = 0.004), NMSS Domain 3 (mood/apathy) (p = 0.003), and NMSS Domain 5 (attention/memory) (p = 0.003).

CONCLUSIONS

The study revealed substantial differences between motor subtypes, underscoring the complexity of PD. These findings highlight the importance of comprehensive evaluations of both MS and NMSs to optimize patient care, improve quality of life, and fit well within the framework of the existing hypotheses of PD subtypes.

A decision support system based on recurrent neural networks to predict medication dosage for patients with Parkinson's disease

Using deep learning has demonstrated significant potential in making informed decisions based on clinical evidence. In this study, we deal with optimizing medication and quantitatively present the role of deep learning in predicting the medication dosage for patients with Parkinson's disease (PD). The proposed method is based on recurrent neural networks (RNNs) and tries to predict the dosage of five critical medication types for PD, including levodopa, dopamine agonists, monoamine oxidase-B inhibitors, catechol-O-methyltransferase inhibitors, and amantadine. Recurrent neural networks have memory blocks that retain crucial information from previous patient visits. This feature is helpful for patients with PD, as the neurologist can refer to the patient's previous state and the prescribed medication to make informed decisions. We employed data from the Parkinson's Progression Markers Initiative. The dataset included information on the Unified Parkinson's Disease Rating Scale, Activities of Daily Living, Hoehn and Yahr scale, demographic details, and medication use logs for each patient. We evaluated several models, such as multi-layer perceptron (MLP), Simple-RNN, long short-term memory (LSTM), and gated recurrent units (GRU). Our analysis found that recurrent neural networks (LSTM and GRU) performed the best. More specifically, when using LSTM, we were able to predict levodopa and dopamine agonist dosage with a mean squared error of 0.009 and 0.003, mean absolute error of 0.062 and 0.030, root mean square error of 0.099 and 0.053, and R-squared of 0.514 and 0.711, respectively.

Effect of robot-assisted gait training on motor dysfunction in Parkinson's patients:A systematic review and meta-analysis

BACKGROUND

Robot-assisted gait training (RAGT) has been reported to treat motor dysfunction in patients with Parkinson's disease (PD) in the last few years. However, the benefits of RAGT for treating motor dysfunction in PD are still unclear.

OBJECTIVES

To investigate the efficacy of RAGT for motor dysfunction in PD patients.

METHODS

We searched PubMed, Web of Science, Cochrane Library, Embase, CNKI, Wanfang, Chinese Biomedical Literature Database (CBM), and Chinese VIP Database for randomized controlled trials investigating RAGT to improve motor dysfunction in PD from the databases' inception dates until September 1, 2022. The following outcome indexes were employed to evaluate motor dysfunction: the Berg Balance Scale (BBS), Activities-specific Balance Confidence Scale (ABC), 10-Meter Walk Test gait speed (10-MWT), gait speed, stride length, cadence Unified Parkinson Disease Rating Scale Part III (UPDRS III), 6-Minute Walk Test (6MWT), and the Timed Up and Go test (TUG). The meta-analysis was performed using the proper randomeffect model or fixed-effect model to evaluate the difference in efficacy between the RAGT and the control groups. The Cochrane Risk of Bias Tool was used for the included studies and Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) was used to interpret the certainty of the results.

RESULTS

The results consisted of 17 studies comprising a total of 670 participants. Six hundred and seven PD patients with motor dysfunction were included: 335 in the RAGT group and 335 in the control group. This meta-analysis results established that when compared with the control group, robot-assisted gait training improved the BBS results of PD patients (MD: 2.80, 95%CI: 2.11-3.49, P< 0.00001), ABC score (MD: 7.30, 95%CI: 5.08-9.52, P< 0.00001), 10-MWT (MD: 0.06, 95%CI: 0.03-0.10, P= 0.0009), gait speed (MD: 3.67, 95%CI: 2.58-4.76, P< 0.00001), stride length (MD: 5.53, 95%CI: 3.64-7.42, P< 0.00001), cadence (MD: 4.52, 95%CI: 0.94-8.10, P= 0.01), UPDRS III (MD: -2.16, 95%CI: -2.48--1.83, P< 0.00001), 6MWT (MD: 13.87, 95%CI: 11.92-15.82, P< 0.00001). However, RAGT did not significantly improve the TUG test result of patients with PD (MD =-0.56, 95% CI: -1.12-0.00, P= 0.05). No safety concerns or adverse reactions among robot-assisted gait training patients were observed.

CONCLUSION

Even though RAGT can improve balance function, walking function, and gait performance and has demonstrated positive results in several studies, there is currently insufficient compelling evidence to suggest that it can improve all aspects of lower motor function.

Opicapone versus entacapone: Head-to-head retrospective data-based comparison of healthcare resource utilization in people with Parkinson's disease new to catechol-O-methyltransferase (COMT) inhibitor treatment

BACKGROUND AND PURPOSE

Motor fluctuations are a significant driver of healthcare resource utilization (HCRU) in people with Parkinson's disease (pwPD). A common management strategy is to include catechol-O-methyltransferase (COMT) inhibition with either opicapone or entacapone in the levodopa regimen. However, to date, there has been a lack of head-to-head data comparing the two COMT inhibitors in real-world settings. The aim of this study was to evaluate changes in HCRU and effect on sleep medications when opicapone was initiated as first COMT inhibitor versus entacapone.

METHODS

In this retrospective cohort study, we assessed HCRU outcomes in pwPD naïve to COMT inhibition via UK electronic healthcare records (Clinical Practice Research Datalink and Hospital Episodes Statistics databases, June 2016 to December 2019). HCRU outcomes were assessed before (baseline) and after COMT inhibitor prescription at 0-6 months, 7-12 months and 13-18 months. Opicapone-treated pwPD were algorithm-matched (1:4) to entacapone-treated pwPD.

RESULTS

By 6 months, treatment with opicapone resulted in 18.5% fewer neurology outpatient visits compared to entacapone treatment; this effect was maintained until the last follow-up (18 months). In the opicapone group, the mean levodopa equivalent daily dose decreased over the first year and then stabilized, whereas the entacapone-treated group showed an initial decrease in the first 6 months followed by a dose increase between 7 and 18 months. Neither COMT inhibitor had a significant impact on sleep medication use.

CONCLUSIONS

This head-to-head study is the first to demonstrate, using 'real-world' data, that initiating COMT inhibition with opicapone is likely to decrease the need for post-treatment HCRU versus initiation of COMT inhibition with entacapone.

Oral [60]fullerene reduces neuroinflammation to alleviate Parkinson's disease via regulating gut microbiome

Neuroinflammation is considered to drive the pathogenic process of neuronal degeneration in Parkinson's disease (PD). However, effective anti-neuroinflammation therapeutics for PD still remain dissatisfactory. Here we explore a robust therapeutic strategy for PD using anti-neuroinflammatory fullerenes. Methods: Oral fullerene was prepared by a ball-milling method. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model was used to investigate the therapeutic effects and mechanisms of it. The gut microenvironment was evaluated by 16S rRNA gene sequencing, gas chromatography-mass spectrometry, quantitative polymerase chain reaction (Q-PCR), and western blot (WB). The neuroinflammation and neurodegeneration were evaluated by pathological analysis, Elisa kits, transmission electron microscopy, Q-PCR, WB and so on. Toxicity was assessed by weight, blood test and hematoxylin-eosin (HE) staining. Results: Oral fullerene therapeutic system that dissolved [60]fullerene into olive oil (abbreviated as OFO) was dexterously designed, which could reduce neuroinflammation via regulating the diversity of gut microbiome, increasing the contents of short chain fatty acids (SCFAs) and recovering the integrity of gut barrier. Accordingly, the reduction of neuroinflammation prevented dopaminergic neuronal degeneration. And thus, OFO significantly ameliorated motor deficits and fundamentally reversed dopamine (DA) loss in MPTP-induced PD mice. Of note, OFO exhibited low toxicity towards the living body. Conclusion: Our findings suggest that OFO is a safe-to-use, easy-to-apply, and prospective candidate for PD treatment in clinic, opening a therapeutic window for neuroinflammation-triggered neurodegeneration.

Importance of time to ON versus wearing OFF in total daily OFF time experienced by patients with Parkinson's disease

Most patients with Parkinson's disease (PD) receiving levodopa (LD)/DOPA decarboxylase inhibitors develop motor fluctuations with an increasing amount of OFF time, negatively impacting patient quality of life. Herein, we review the evidence supporting the substantial, yet underappreciated contribution of delays in time to ON (including delayed ON and no ON) to total daily OFF time. Most clinical studies use patient diaries that do not capture time to ON and wearing OFF separately as related to LD dosing, and consequently, most OFF time has generally been attributed to wearing OFF. Hence, most treatment regimens focus on reducing wearing OFF by changing LD dosing/formulations and/or using "ON-extenders" (eg, catechol-o-methyltransferase inhibitors, monoamine oxidase-B inhibitors, extended-release amantadine, and adenosine A2A receptor antagonists). However, the literature describing approved treatments for PD that has focused on delays in time to ON is sparse and suggests this type of OFF may comprise more than twice the amount of total daily OFF time as wearing OFF. Here, we advocate for the importance of measuring and adequately addressing delays in time to ON and build support for the consistent inclusion of the time to ON measurement in future clinical trials.

Risk factors for developing dyskinesia among Parkinson's disease patients with wearing-off: J-FIRST

BACKGROUND

Dyskinesia frequently occurs during long-term treatment with levodopa in patients with Parkinson's disease (PD) and impacts quality of life. Few studies have examined risk factors for developing dyskinesia in PD patients exhibiting wearing-off. Therefore, we investigated the risk factors and impact of dyskinesia in PD patients exhibiting wearing-off.

METHODS

We investigated the risk factors and impact of dyskinesia in a 1-year observational study of Japanese PD patients exhibiting wearing-off (J-FIRST). Risk factors were assessed by logistic regression analyses in patients without dyskinesia at study entry. Mixed-effect models were used to evaluate the impact of dyskinesia on changes in Movement Disorder Society-Unified PD Rating Scale (MDS-UPDRS) Part I and PD Questionnaire (PDQ)-8 scores from one timepoint before dyskinesia was observed.

RESULTS

Of 996 patients analyzed, 450 had dyskinesia at baseline, 133 developed dyskinesia within 1 year, and 413 did not develop dyskinesia. Female sex (odds ratio [95% confidence interval]: 2.636 [1.645-4.223]) and administration of a dopamine agonist (1.840 [1.083-3.126]), a catechol-O-methyltransferase inhibitor (2.044 [1.285-3.250]), or zonisamide (1.869 [1.184-2.950]) were independent risk factors for dyskinesia onset. MDS-UPDRS Part I and PDQ-8 scores increased significantly after the onset of dyskinesia (least-squares mean change [standard error] at 52 weeks: 1.11 [0.52], P = 0.0336; 1.53 [0.48], P = 0.0014; respectively).

CONCLUSION

Female sex and administration of a dopamine agonist, a catechol-O-methyltransferase inhibitor, or zonisamide were risk factors for dyskinesia onset within 1 year in PD patients exhibiting wearing-off. Nonmotor symptoms and quality of life deteriorated after dyskinesia onset.

Istradefylline for OFF Episodes in Parkinson’s Disease: A US Perspective of Common Clinical Scenarios

The effective management of OFF episodes remains an important unmet need for patients with Parkinson’s disease (PD) who develop motor complications with long-term levodopa therapy. Istradefylline is a selective adenosine A_2A receptor antagonist for the treatment of patients with PD experiencing OFF episodes while on levodopa/decarboxylase inhibitor. Originally approved in Japan, istradefylline was recently approved in the USA. In this article, we provide a specific review of the four clinical studies that the FDA included in the approval of istradefylline in the USA, and discuss common clinical scenarios, based on our experience, where treatment with istradefylline may benefit patients experiencing motor fluctuations.

Opicapone Use in Clinical Practice across Germany: A Sub-Analysis of the OPTIPARK Study in Parkinson's Disease Patients with Motor Fluctuations

INTRODUCTION

The OPTIPARK study confirmed the effectiveness and safety of opicapone as adjunct therapy to levodopa in patients with Parkinson's disease (PD) and motor fluctuations under real-world conditions. The aim of this sub-analysis was to evaluate opicapone in the German patient cohort of OPTIPARK in order to provide country-specific data.

METHODS

OPTIPARK was an open-label, single-arm study conducted in routine clinical practice across Germany and the UK. Patients with PD and motor fluctuations received once-daily opicapone 50 mg for 3 months in addition to levodopa. The primary endpoint was Clinicians' Global Impression of Change (CGI-C). Secondary assessments included Patients' Global Impressions of Change (PGI-C), Unified Parkinson's Disease Rating Scale (UPDRS) I-IV, Parkinson's Disease Questionnaire (PDQ-8), and Non-Motor Symptoms Scale (NMSS). This sub-analysis reports outcomes from the German patients only.

RESULTS

Overall, 363 (97.6%) of the 372 patients included in the German cohort received ≥1 dose of opicapone and 291 (80.2%) completed the study. Improvements on CGI-C and PGI-C were reported by 70.8% and 76.3% of patients, respectively. UPDRS scores improved for activities of daily living during OFF time by -3.3 ± 4.5 points and motor scores during ON time by -5.3 ± 7.9 points. PDQ-8 and NMSS scores also demonstrated improvements. Treatment emergent adverse events considered at least possibly related to opicapone occurred in 37.7% of patients, with most being of mild or moderate intensity.

CONCLUSION

Opicapone added to levodopa in patients with PD and motor fluctuations was effective and generally well tolerated in routine clinical practice across Germany.

Amantadine delayed release/extended release capsules significantly reduce OFF time in Parkinson's disease

Maintaining consistent levodopa benefits while simultaneously controlling dyskinesia can be difficult. Recently, an amantadine delayed release/extended release (DR/ER) formulation (Gocovri^®) indicated for dyskinesia received additional FDA approval as an adjunct to levodopa for the treatment of OFF episodes. We evaluated OFF time reductions with amantadine-DR/ER in a pooled analysis of two phase III amantadine-DR/ER trials (NCT02136914, NCT02274766) followed by a 2-year open-label extension trial (NCT02202551). OFF outcomes were analyzed for the mITT population, as well as stratified by baseline OFF time of ≥2.5 h/day or <2.5 h/day. At Week 12, mean placebo-subtracted treatment difference in OFF time was −1.00 [−1.57, −0.44] h in the mITT population (n = 196), −1.2 [−2.08, −0.32] h in the ≥2.5 h subgroup (n = 102) and −0.77 [−1.49, −0.06] in the <2.5 h subgroup (n = 94). Amantadine-DR/ER-treated participants showed reduced MDS-UPDRS Part IV motor fluctuation subscores by week 2 that were maintained below baseline to Week 100.

Efficacy and safety of combination therapy with pramipexole and levodopa vs levodopa monotherapy in patients with Parkinson disease: A systematic review and meta-analysis

BACKGROUND

Pramipexole (P) or levodopa (L) treatment has been suggested as a therapeutic method for Parkinson disease (PD) in many clinical studies. Nonetheless, the combined effects of 2 drugs for PD patients are not completely understood.The aim of this research was to evaluate the clinical efficacy and safety of P plus L (P+L) combination therapy in the treatment of PD compared to that of L monotherapy, in order to confer a reference for clinical practice.

METHODS

Randomized controlled trials (RCTs) of P+L for PD published up to April, 2020 were retrieved. Standardized mean difference (SMD), odds ratio (OR), and 95% confidence interval (CI) were calculated and heterogeneity was measured with the I2 test. Sensitivity analysis was also carried out. The outcomes of interest were as follows: the efficacy, unified Parkinson disease rating scale (UPDRS) scores, Hamilton depression rating scale score or adverse events.

RESULTS

Twenty-four RCTs with 2171 participants were included. Clinical efficacy of P+L combination therapy was significantly better than L monotherapy (9 trials; OR 4.29, 95% CI 2.78 to 6.64, P < .00001). Compared with L monotherapy, the pooled effects of P+L combination therapy on UPDRS score were (22 trials; SMD -1.31, 95% CI -1.57 to -1.04, P < .00001) for motor UPDRS score, (16 trials; SMD -1.26, 95% CI -1.49 to -1.03, P < .00001) for activities of daily living UPDRS score, (12 trials; SMD -1.02, 95% CI -1.27 to -0.77, P < .00001) for mental UPDRS score, (10 trials; SMD -1.54, 95% CI -1.93 to -1.15, P < .00001) for complication UPDRS score. The Hamilton depression rating scale score showed significant decrease in the P+L combination therapy compared to L monotherapy (12 trials; SMD -1.56, 95% CI -1.90 to -1.22, P < .00001). In contrast to L monotherapy, P+L combination therapy reduced the number of any adverse events obviously in PD patients (16 trials; OR 0.36, 95% CI 0.27 to 0.50, P < .00001).

CONCLUSIONS

P+L combination therapy is superior to L monotherapy for improvement of clinical symptoms in PD patients. Moreover, the safety profile of P+L combination therapy is better than that of L monotherapy. Further well-designed, multicenter RCTs needed to identify these findings.

Fluctuating pain in Parkinson's disease: Its prevalence and impact on quality of life

Pain is a common non-motor symptom in Parkinson's disease (PD) patients, and the incidence of fluctuating pain may be improved by taking levodopa. There are only a few detailed reports regarding fluctuating pain. In this study, 331 PD patients were classified into three groups: no-pain group (67.4%), non-fluctuating pain group (22.1%), and fluctuating pain group (10.6%). We evaluated patients' background and its impact on the quality of life (QOL) of each group. The pain group exhibited higher levels of depression (p < 0.0001), had a higher frequency of visual hallucinations (p = 0.007), and lower QOL (p < 0.0001) compared with the no-pain group. The fluctuating pain group had a younger onset (p = 0.006), higher Hoehn & Yahr stage (p = 0.018), and higher frequency of wearing-off (p < 0.001) and dyskinesia (p = 0.007) than the other groups. We compared the Parkinson's Disease Questionnaire-8 summary index (PDQ-8 SI) in each pain group to the no-pain group using analysis of variance. As a result, PDQ-8 SI was significantly higher in both the non-fluctuating and fluctuating pain groups (p < 0.0001). Pain is regarded as a non-negligible symptom that affects the QOL of PD patients, and given the unique characteristics, fluctuating pain might be considered as an independent clinical subtype of PD.

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Clinical characteristics of fluctuating pain in Parkinson's disease

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The prevalence of pain in PD was 10.6%, of which 32.4% showed fluctuating pain.

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Fluctuating pain is related to younger age of onset and severity of disease.

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Pain affects the quality of life of patients with Parkinson's disease.

Inclusion of Levodopa into β-Cyclodextrin: A Comprehensive Computational Study

This study focused on the inclusion of levodopa (LVDP) into β-cyclodextrin (BCD) using various computational methods such as quantum mechanics (QM), molecular dynamics/steered molecular dynamics (MD/SMD), and QM/molecular mechanics/Poison-Boltzmann surface area (QM/MM/PBSA). The QM results assigned the most significant charge-transfer atoms and the higher stability of LVDP in the aqueous phase. The MD results indicate the formation of a 1:1 complex with a reasonable estimation of the effective radius of the complex, the significant contribution of hydrogen bonding in the binding energy, and the enhancement of the water solubility of LVDP. By accounting for the water hydrogen bonds and their dipolar effects, QM/MM calculations lead to the more accurate IR spectrum and binding energy of the BCD-LVDP complex. By considering carboxylic and amine functional groups' more precise arrangement, QM/MM assigns stronger hydrogen bonds between LVDP and BCD. While all the methods provide a reasonable estimation of the binding energy, the most accurate value (-4.14 kcal/mol) is obtained from QM/MM/PBSA.

Effectiveness of Long-Term Physiotherapy in Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Long-term physiotherapy is acknowledged to be crucial to manage motor symptoms for Parkinson's disease (PD) patients, but its effectiveness is not well understood.

OBJECTIVE

This systematic review and meta-analysis aimed to assess the evidence regarding the effectiveness of long-term physiotherapy to improve motor symptoms and reduce antiparkinsonian medication dose in PD patients.

METHODS

Pubmed, Cochrane, PEDro, and CINAHL were searched for randomized controlled trials before August 31, 2020 that investigated the effectiveness of physiotherapy for 6 months or longer on motor symptoms and levodopa-equivalent dose (LED) in PD patients with Hoehn and Yahr stage 1- 3. We performed random effects meta-analyses for long-term physiotherapy versus no/control intervention and estimated standard mean differences with 95% confidence intervals (CIs). Levels of evidence were rated by the Grading of Recommendation Assessment, Development and Evaluation approach.

RESULTS

From 2,940 studies, 10 studies involving 663 PD patients were assessed. Long-term physiotherapy had favorable effects on motor symptoms in off medication state [- 0.65, 95% CI - 1.04 to - 0.26, p = 0.001] and LED [- 0.49, 95% CI - 0.89to - 0.09, p = 0.02]. Subgroup analyses demonstrated favorable effects on motor symptoms in off medication state by aerobic exercise [- 0.42, 95% CI - 0.64 to - 0.20, p < 0.001] and LED by multidisciplinary rehabilitation of primarily physiotherapy [- 1.00, 95% CI - 1.44 to - 0.56, p < 0.001]. Quality of evidence for aerobic exercise and multidisciplinary rehabilitation were low and very low.

CONCLUSION

This review provided evidence that long-term physiotherapy has beneficial impact on motor symptoms and antiparkinsonian medication dose in PD patients and could motivate implementation of long-term physiotherapy.

Mild traumatic brain injury exacerbates Parkinson's disease induced hemeoxygenase-2 expression and brain pathology: Neuroprotective effects of co-administration of TiO2 nanowired mesenchymal stem cells and cerebrolysin

Mild traumatic brain injury (mTBI) is one of the leading predisposing factors in the development of Parkinson's disease (PD). Mild or moderate TBI induces rapid production of tau protein and alpha synuclein (ASNC) in the cerebrospinal fluid (CSF) and in several brain areas. Enhanced tau-phosphorylation and ASNC alters the molecular machinery of the brain leading to PD pathology. Recent evidences show upregulation of constitutive isoform of hemeoxygenase (HO-2) in PD patients that correlates well with the brain pathology. mTBI alone induces profound upregulation of HO-2 immunoreactivity. Thus, it would be interesting to explore whether mTBI exacerbates PD pathology in relation to tau, ASNC and HO-2 expression. In addition, whether neurotrophic factors and stem cells known to reduce brain pathology in TBI could induce neuroprotection in PD following mTBI. In this review role of mesenchymal stem cells (MSCs) and cerebrolysin (CBL), a well-balanced composition of several neurotrophic factors and active peptide fragments using nanowired delivery in PD following mTBI is discussed based on our own investigation. Our results show that mTBI induces concussion exacerbates PD pathology and nanowired delivery of MSCs and CBL induces superior neuroprotection. This could be due to reduction in tau, ASNC and HO-2 expression in PD following mTBI, not reported earlier. The functional significance of our findings in relation to clinical strategies is discussed.

Medical Management and Prevention of Motor Complications in Parkinson's Disease

Levodopa is the most effective medication for the treatment of the motor symptoms of Parkinson's disease. However, over time, the clinical response to levodopa becomes complicated by a reduction in the duration and reliability of motor improvement (motor fluctuations) and the emergence of involuntary movements (levodopa-induced dyskinesia). Strategies that have been attempted in an effort to delay the development of these motor complications include levodopa sparing and continuous dopaminergic therapy. Once motor complications occur, a wide array of medical treatments is available to maximize motor function through the day while limiting dyskinesia. Here, we review the clinical features, epidemiology, and risk factors for the development of motor complications, as well as strategies for their prevention and medical management.

High levodopa plasma concentration after oral administration predicts levodopa-induced dyskinesia in Parkinson's disease

INTRODUCTION

In patients with Parkinson's disease (PD), pulsatile dopaminergic stimulation may be a primary cause of levodopa-induced dyskinesia (LID). We aimed to investigate the correlation between levodopa pharmacokinetics (PK) and LID in PD.

METHODS

We retrospectively reviewed the consecutive series of 255 PD patients without LID who underwent PK assessments with 100 mg levodopa. The type of peripheral decarboxylase inhibitor used in the PK assessments was determined by the usual prescription of the formulations of levodopa (10 mg carbidopa [n = 185] and 25 mg benserazide [n = 70]).

RESULTS

During a median follow-up of 32 months (IQR, 16-49 months), 73 patients (29%) developed LID. Compared with patients who did not develop LID (PD-LID-), those who developed LID (PD-LID+) were younger (p = 0.003) and had significantly higher maximum levodopa concentration (Cmax) (p = 0.002) and area under the curve (p < 0.001), LEDD (p < 0.001), and improvement of motor symptoms (p = 0.009). In the multivariate Cox proportional hazards models, Cmax and AUC were associated with incident LID (Hazard Ratio [HR] 1.11, 95% confidence interval [CI] 1.03-1.19 and HR 1.13, 95% CI 1.03-1.24, respectively). In addition, younger age, benserazide use, LEDD, and MAOBI use were associated with incident LID.

CONCLUSION

High levodopa plasma concentration after oral administration was associated with incident LID in patients with PD.

Are There Benefits in Adding Catechol-O Methyltransferase Inhibitors in the Pharmacotherapy of Parkinson's Disease Patients? A Systematic Review

BACKGROUND

A qualified consensus suggests that a combination of levodopa with a peripherally acting dopa decarboxylase inhibitor continues to present the gold standard treatment of Parkinson's disease (PD). However, as the disease progresses the therapeutic window of levodopa becomes narrowed. Pharmacological strategies for motor fluctuations are focused on providing less pulsatile and more continuous dopaminergic stimulation. Peripheral catechol-O-methyltransferase (COMT) inhibition improves the bioavailability of levodopa and results in a prolonged response.

OBJECTIVE

The primary aim of this study was to investigate the efficacy and safety of the two available COMT inhibitors; entacapone and tolcapone and the recently introduced opicapone.

METHODS

Electronic databases were systematically searched for original studies published within the last 37 years. In addition, lists of identified studies, reviews and their references were examined.

RESULTS

Twelve studies fulfilled the inclusion criteria. 3701 patients with PD were included in this systematic review.

CONCLUSIONS

Adjuvant treatment of PD patients experiencing motor fluctuations with entacapone resulted in improvement of motor function and was well tolerated. Therefore, entacapone presented an acceptable benefit to risk ratio. Tolcapone appeared to result in a greater therapeutic effect. However, this was not consistent across all motor variables and studies, and thus would not support its use, given the current onerous monitoring that is required. Opicapone was not associated with adverse reactions in a phase III trial but did not present a greater efficacy than entacapone, and thus further studies are required in order to illustrate its cost effectiveness.

Real-world pharmacological treatment patterns of patients with young-onset Parkinson's disease in Japan: a medical claims database analysis

INTRODUCTION

Young-onset Parkinson's disease is reported to comprise 5-10% of all Parkinson's disease cases; however, as physicians encounter a limited number of these patients, their treatment patterns are still unclear.

METHODS

We performed a descriptive study using the large Japanese medical claims database to describe the epidemiology and real-world pharmacological treatment patterns of newly diagnosed patients with young-onset Parkinson's disease. Patients aged 21-50 years in whom Parkinson's disease was newly diagnosed between January 1, 2005 and March 31, 2016 were included. We excluded individuals with Parkinson's-related diseases and those using antipsychotics to eliminate the possibility of drug-induced parkinsonism. The patients' demographics, comorbidities, prescribing patterns, and changes in levodopa equivalent daily dose were analyzed.

RESULTS

We identified 131 newly diagnosed young-onset Parkinson's disease patients (median age, 44.2 years). The most common comorbidities were depression (23.7%), hypertension (23.7%), and insomnia (22.9%). Of these patients, 122 were prescribed antiparkinson drugs. During the study period, the proportion of patients who were prescribed dopamine agonists, levodopa, and anticholinergics were 77.1%, 44.3%, and 27.5%, respectively. Dopamine agonists (49.2%) were most commonly prescribed initially, followed by anticholinergics (23.8%), levodopa (19.7%), and others (4.1%). The levodopa equivalent daily dose increased steadily with longer disease duration.

CONCLUSIONS

Dopamine agonists were most frequently prescribed during the study period and were the initial treatment of choice. We also observed a change in levodopa equivalent daily dose over the disease course. This study provides a descriptive overview of real-world prescribing patterns in young-onset Parkinson's disease patients.