Rotigotine Transdermal Patch for Motor and Non-motor Parkinson's Disease: A Review of 12 Years' Clinical Experience

Using Polymers as Crystal Inhibitors to Prevent the Crystallization of the Rotigotine Patch

This study aimed to enhance the stability of the Rotigotine (ROT) patch using polymers as crystal inhibitors. Three polymers (Poloxamer 188, Soluplus, TPGS) were selected as crystal inhibitors to formulate ROT patches with varying drug loadings (20%, 40%, 60%, and 80%, w/w). SEM and XRD analysis revealed that the Soluplus and Soluplus-TPGS groups with a high concentration (80%, w/w) of ROT could be stored at room temperature for at least 90 days without crystallization. Moreover, the crystallization nucleation time and growth rate were utilized to assess the ability of Poloxamer 188, Soluplus, and TPGS to hinder the formation of ROT crystals and slow down its crystallization rate. Molecular docking results elucidated the intermolecular forces between ROT and different polymers, revealing their mechanisms for crystal inhibition. The ROT-Soluplus-TPGS combination exhibited the lowest binding free energy (-5.3 kcal/mol), indicating the highest binding stability, thereby effectively reducing crystal precipitation. In vitro skin permeation studies demonstrated that ROT patches containing crystal inhibitors exhibited promising transdermal effects. With increasing ROT concentration, the cumulative drug permeation substantially increased, while the lag time was notably reduced. This study offers novel insights for the development of ROT patches.

A liquid crystal in situ gel based on rotigotine for the treatment of Parkinson's disease

One of the most common neurodegenerative illnesses is Parkinson's disease (PD). Rotigotine (RTG) is a dopamine agonist that exerts anti-Parkinsonian effects through dopamine receptor agonism to improve motor symptoms and overall performance in PD patients. In this study, an in situ liquid crystal gel called rotigotine-gel (RTG-gel) was developed using soya phosphatidyl choline (SPC) and glycerol dioleate (GDO) to provide long-acting slow-release benefits of rotigotine while minimizing side effects. This study prepared the RTG-gel precursor solution using SPC, GDO, and ethanol (in the ratio of 54:36:10, w/w/w). The internal structures of the gel were confirmed by crossed-polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), and differential scanning calorimetry (DSC). The rheological properties of the RTG-gel precursor solution indicate a favorable combination of low viscosity and excellent flowability. The gel that produced during water absorption was also highly viscous and structurally stable, which helped to maintain the drug delayed release at the injection site. In vitro release assays showed that the in vitro release of RTG-gel followed Ritger-Peppas. The RTG-gel precursor solution was administered by subcutaneous injection, and the results of in vivo pharmacokinetic tests in SD rats showed that the plasma elimination half-life (t1/2) was 59.28 ± 16.08 h; the time to peak blood concentration (Tmax) was 12.00 ± 10.32 h, and the peak concentration (Cmax) was 29.9 ± 10.10 ng/mL. The blood concentration remained above 0.1 ng/mL for 20 days after administration and was still detectable after 31 days of administration, and the bioavailability of RTG can reach 72.59%. The results of in vitro solvent exchange tests showed that the RTG-gel precursor solution undergoes rapid exchange upon contact with PBS, and the diffusion of ethanol can reach 48.1% within 60 min and 80% within 8 h. The results of cytotoxicity test showed 89.27 ± 4.32% cell survival after administration of the drug using RTG-gel. The results of tissue extraction at the administration site showed that healing of the injection site without redness and hemorrhage could be observed after 14 days of injection. The results of tissue section of the administered site showed that the inflammatory cells decreased and granulation tissue appeared after 14 days of administration, and there was basically no inflammatory cell infiltration after 35 days of administration, and the inflammatory reaction was basically eliminated. It shows that RTG-gel has some irritation to the injection site, but it can be recovered by itself in the later stage, and it has good biocompatibility. In summary, RTG-gel might be a potential RTG extended-release formulation for treating PD.

Transdermal Rotigotine at End-of-Life for Parkinson's Disease: Association With Measures of Distress

BACKGROUND

End-of-life (EOL) care for Parkinson's disease (PD) can be challenging when oral medications are no longer tolerated.

MEASURES

To assess EOL prescribing for people with PD (PWP), focusing on rotigotine dosing and proxy measures of distress: benzodiazepine and opioid use.

INTERVENTION

A retrospective audit of patient records from PWP who died between January 2019 and May 2022 at the Royal Hobart Hospital (RHH), Australia, was conducted. Data was systematically collated on demographics, symptoms, levodopa equivalent daily dose (LEDD) and rotigotine, oral morphine equivalent (OME) and benzodiazepine doses in the last 72 hours of life .

OUTCOMES

Pain (72%), respiratory secretions (66%) and agitation (66%) were the most documented EOL symptoms. 83% (n = 52) of PWP were eligible for rotigotine and, of those, 13% (n = 7) received the correct dose, 38% (n = 20) a lower dose, 12% (n = 6) a higher dose and 37% (n = 19) did not receive any. Rotigotine dose was positively associated with total (P = 0.016) and PRN (P = 0.037) benzodiazepine dose. LEDD was positively associated with total benzodiazepine (P = 0.018) and total OME dose (P = 0.046). Contraindicated dopamine antagonists were prescribed for 43% of PWP and administered in 31% of those cases.

CONCLUSIONS

Rotigotine dose and admission LEDD were both associated with proxy measures of distress in the last 72 hours of life. This suggests cautious use of rotigotine at EOL. LEDD may help identify patients at risk of distress. Rates of inappropriate prescribing and symptom prevalence were high, indicating a need for further staff education to optimize the care of PWP.

Non-oral continuous drug delivery based therapies and sleep dysfunction in Parkinson's disease

Continuous drug delivery (CDD) has emerged as a feasible and pragmatic therapeutic option for dopamine replacement therapy in advanced Parkinson's disease (PD). CDD aims to mimic the physiological tonic dopamine release from striatal dopaminergic neurons and thus reduces the severity and duration of motor and non-motor fluctuations partly related to pulsatile levodopa stimulation. Non-motor symptoms and fluctuations are ubiquitous in PD and include sleep dysfunction, a problem that occurs in over 90% of PD patients across all stages, from prodromal to palliative. In this review, we discuss the currently available and in development non-oral dopaminergic CDD strategies with a focus on their efficacy in the treatment of the burdensome sleep dysfunction in PD.

Clinical Manifestations of Subjective Sleep Disorders in Chinese Patients with Parkinson's Disease and Their Relationship with Dopaminergic Drugs

INTRODUCTION

Sleep disorders are common in Parkinson's disease (PD) and significantly impact quality of life. Herein, we surveyed the incidence and severity of sleep disorders in Chinese PD patients and observed their relationship with dopaminergic drugs.

METHODS

We collected the demographic and disease information of 232 PD patients. The incidence and severity of sleep disorders were surveyed with the Parkinson's disease sleep scale (PDSS) Chinese version. Data on dopaminergic drug intake were collected and converted to levodopa equivalent doses (LED).

RESULTS

The average total score of PDSS in 232 patients was 119.3 ± 19.7. There was a significant difference in PDSS scores between groups classified by the Hoehn-Yahr (H&Y) stage, but not between the groups classified by the type of dopaminergic drugs. Stepwise regression analysis revealed that the LED of dopaminergic drugs taken before bedtime (p < 0.00), LED of dopaminergic drugs taken over a 24-h period (p < 0.00), and scores of the Hamilton Rating Scale for Depression (HAMD) (p = 0.01) were determinants of PDSS.

CONCLUSION

Sleep disorders in PD patients may be multifactorial. High dosage of dopaminergic drugs taken prior to sleep, daily total high dosage of dopaminergic drugs, and depression exert negative effects on subjective sleep. The timing and dosage of dopaminergic drugs taken before bedtime should be considered in PD management.

Risk factors for postoperative complications in patients with Parkinson disease: A single center retrospective cohort study

Surgical treatment for patients with Parkinson disease (PD) under general anesthesia has become frequent. PD is a significant predictor of postoperative complications. However, the factors that predict complications in patients with PD remain unknown. We retrospectively recruited patients with PD who underwent surgery between April 2015 and March 2019. The prevalence of postoperative complications was analyzed. We compared the patient characteristics, medical data, and surgical data between patients with and without postoperative complications. We also estimated the odds ratios (OR) for postoperative complications in patients with PD who underwent surgery. Sixty-five patients were enrolled. Eighteen patients presented with 22 complications, including urinary tract infections (UTI) (n = 3; 5%), pneumonia (n = 1; 2%), surgical site infections (SSI) (n = 3; 5%), postoperative delirium (POD) (n = 7; 10%), and others (n = 8; 12%). Four patients presented with 2 complications each. The operation time, the red blood cell transfusion and the rate of rotigotine usage were higher in patients with complications than those without (314 ± 197 min vs 173 ± 145 min, P = .006; 0 [0-560] mL vs 0 [0-0] mL, P = .02; 39% vs 6%, P = .003, respectively) (mean ± standard deviation or median [interquartile range]). Preoperative rotigotine usage (OR: 9.33; 95% confidential interval [CI]: 2.07-42.07; P = .004) was an independent risk factors for postoperative complications. The findings indicate that clinicians should closely monitor postoperative complications when patients with PD who have received transdermal dopamine agonists undergone longer time surgery.

The complex molecular pharmacology of the dopamine D2 receptor: Implications for pramipexole, ropinirole, and rotigotine

With L-DOPA, dopamine agonists such as pramipexole, ropinirole and rotigotine constitute key therapeutic options for the management of motor symptoms of Parkinson's disease. These compounds exert their beneficial effect on motor behaviours by activating dopamine D₂-class receptors and thereby compensating for the declining dopaminergic transmission in the dorsal striatum. Despite a strong similarity in their mechanism of action, these three dopamine agonists present distinct clinical profiles, putatively underpinned by differences in their pharmacological properties. In this context, this review aims at contributing to close the gap between clinical observations and data from molecular neuropharmacology by exploring the properties of pramipexole, ropinirole and rotigotine from both the clinical and molecular perspectives. Indeed, this review first summarizes and compares the clinical features of these three dopamine agonists, and then explores their binding profiles at the different dopamine receptor subtypes. Moreover, the signalling profiles of pramipexole, ropinirole and rotigotine at the D₂ receptor are recapitulated, with a focus on biased signalling and the potential therapeutic implications. Overall, this review aims at providing a unifying framework of interpretation for both clinicians and fundamental pharmacologists interested in a deep understanding of the pharmacological properties of pramipexole, ropinirole and rotigotine.

Effective Management of "OFF" Episodes in Parkinson's Disease: Emerging Treatment Strategies and Unmet Clinical Needs

Motor complications related to the chronic administration of levodopa and failure to prevent the neurodegenerative disease process counterbalance the pivotal discovery of levodopa as the cornerstone of PD treatment. Excellent motor control is offered early during the course of treatment, but this diminishes as pathological changes in the striatum lead to synaptic dopamine levels becoming completely dependent on exogenous dopamine. This non-physiologic stimulation of dopamine receptors eventually manifests as OFF episodes. As no disease modifying therapy exists for PD that can disrupt these pathological changes, most research and treatment focuses on optimization of dopaminergic stimulation of striatal receptors so that they mimic tonic, physiologic stimulation as closely as possible. Strategies focusing on these challenges have included non-pharmacologic approaches, optimizing levodopa pharmacokinetics, using adjunctive treatments including those with non-dopaminergic mechanisms, and implementing rescue therapies. Device aided therapies, including surgery, are also available. In this review, we will focus on effective management of motor symptoms related to OFF periods, including emerging strategies. Unmet clinical needs will be discussed, including non-motor symptoms, targeted molecular therapies and disease modifying therapy.

Advances in the Therapeutic Use of Non-Ergot Dopamine Agonists in the Treatment of Motor and Non-Motor Symptoms of Parkinson's Disease

Dopamine (DA) agonists, as an excellent dopamine replacement therapy for patients with early and advanced Parkinson's disease (PD), play a vital role in controlling motor and several nonmotor symptoms. Besides, the application of DA agonists may delay levodopa therapy and the associated risk of motor complications. Indeed, each DA agonist has unique pharmacokinetic and pharmacodynamic characteristics and therefore has different therapeutic efficacy and safety profile. The comorbidities, significant non-motor manifestations, concomitant medications, and clinical features of PD individuals should guide the selection of a specific DA agonist to provide a more patient-tailored treatment option. Thorough knowledge of DA agonists helps clinicians better balance clinical efficacy and side effects. Therefore, this review refers to recent English-written articles on DA agonist therapy for PD patients and summarizes the latest findings on non-ergot DA agonists as well as the advantages and disadvantages of each compound to help clinicians in the selection of a specific DA agonist. In addition, novel D1/D5 partial agonists and new formulations of DA agonists are also discussed.

Effect of Dispersion Medium on Pharmacokinetic Profile of Rotigotine Crystalline Suspension following Subcutaneous Injection

Rotigotine (RTG) is prescribed as a once-daily transdermal patch for managing early Parkinson’s disease (PD), which presents issues such as skin irritation and poor patient adherence. Therefore, the aims of the present study were to formulate aqueous and oily vehicle-based RTG crystalline suspensions for prolonged delivery and to compare their pharmacokinetic profiles and the local behaviors of RTG crystals. RTG-loaded aqueous (AS) and oil suspensions (OS) were fabricated using bead-milling technology (100 mg/mL as RTG), employing carboxymethyl cellulose and sesame oil as suspending agent and oily vehicle, respectively. RTG AS and OS exhibited comparable physical properties in terms of particle size (about 800−900 nm), crystallinity, and dissolution profile, despite higher drug solubility in OS than AS (19.6 and 0.07 mg/mL, respectively). However, AS and OS exhibited markedly distinctive local distribution and inflammatory responses at the injection site, which further promoted different pharmacokinetic patterns following subcutaneous injection in rats. With OS, no drug aggregates were observed with prolonged persistence of the Sudan III-stained oily vehicle at the injection site. In contrast, with AS injection, drug clusters > 7 mm were formed, followed by an enclosure with macrophages and a fibroblastic band. Accordingly, AS exhibited a protracted pharmacokinetic profile over 3 weeks, with prolonged elimination half-life. The local inflammatory response caused by AS injection was almost alleviated after 3 weeks post-dosing. Based on these findings, we conclude that RTG AS system can be a platform to design sophisticated long-acting delivery systems with extended dosing intervals to manage PD.

Why do 'OFF' periods still occur during continuous drug delivery in Parkinson's disease?

Continuous drug delivery (CDD) is used in moderately advanced and late-stage Parkinson’s disease (PD) to control motor and non-motor fluctuations (‘OFF’ periods). Transdermal rotigotine is indicated for early fluctuations, while subcutaneous apomorphine infusion and levodopa-carbidopa intestinal gel are utilised in advanced PD. All three strategies are considered examples of continuous dopaminergic stimulation achieved through CDD. A central premise of the CDD is to achieve stable control of the parkinsonian motor and non-motor states and avoid emergence of ‘OFF’ periods. However, data suggest that despite their efficacy in reducing the number and duration of ‘OFF’ periods, these strategies still do not prevent ‘OFF’ periods in the middle to late stages of PD, thus contradicting the widely held concepts of continuous drug delivery and continuous dopaminergic stimulation. Why these emergent ‘OFF’ periods still occur is unknown. In this review, we analyse the potential reasons for their persistence. The contribution of drug- and device-related involvement, and the problems related to site-specific drug delivery are analysed. We propose that changes in dopaminergic and non-dopaminergic mechanisms in the basal ganglia might render these persistent ‘OFF’ periods unresponsive to dopaminergic therapy delivered via CDD.

Tolerability of overnight rotigotine transdermal patch combined with intrajejunal levodopa infusion at 1 year: a 24-h treatment option in Parkinson's disease

Background

Twenty-four-hour treatment options could provide a continuous drug delivery strategy in advanced Parkinson’s disease and can ameliorate motor and non-motor complications. Use of levodopa infusion is often limited to 12–16 h/day due to its cost. Adjunctive overnight rotigotine transdermal patch is a continuous drug delivery option successfully used in clinical practice coupled with apomorphine infusion. However, real-life data addressing the tolerability of transdermal dopamine agonist therapy with concomitant use of intrajejunal levodopa infusion in advanced Parkinson’s disease are not available.

Objective

To evaluate the tolerability and beneficial effects of combined therapy with overnight rotigotine transdermal patch and intrajejunal levodopa infusion over a follow-up period of 12 months in advanced Parkinson’s disease.

Method

In this retrospective data analysis, data before and after the initiation of the continuous drug delivery combined therapy using overnight rotigotine transdermal patch and intrajejunal levodopa infusion were collected from the ongoing non-motor-international-longitudinal study (NILS) and local clinical practice at King’s College Hospital (London, United Kingdom). 12 advanced Parkinson’s disease patients on intrajejunal levodopa therapy who were additionally treated with overnight rotigotine transdermal patch (mean dose 5.67 ± 4.19 mg) are included. Tolerability over a 12-month period was assessed. In addition, changes in motor symptoms (SCales for Outcomes in Parkinson's disease, SCOPA-Motor), non-motor symptoms (Non-Motor Symptoms Scale, NMSS) and quality of life (Parkinson's disease Questionnaire-8, PDQ-8) before and 12-month after continuous drug delivery combined therapy initiation are evaluated.

Results

Tolerability was 100% irrespective of age, disease duration, stages of disease. (Treatment with overnight rotigotine transdermal patch that was maintained for a minimum of 6 months was considered “tolerated”, primary tolerability). In addition, we noted a significant reduction of the NMSS total score (p = 0.009) and the NMSS domain 3 score (mood and apathy domain) (p = 0.028), although the latter did not remain statistically significant after correction for multiple testing (p2 = 0.252) at 12 months.

Conclusion

Combination of intrajejunal levodopa infusion with overnight rotigotine transdermal patch is well tolerated and extend the beneficial effects of infusion with excellent tolerability; and also improved aspects of mood and apathy sustained at 12 months in advanced Parkinson’s disease.

Parkinson’s Disease and SARS-CoV-2 Infection: Particularities of Molecular and Cellular Mechanisms Regarding Pathogenesis and Treatment

Accumulating data suggest that chronic neuroinflammation-mediated neurodegeneration is a significant contributing factor for progressive neuronal and glial cell death in age-related neurodegenerative pathology. Furthermore, it could be encountered as long-term consequences in some viral infections, including post-COVID-19 Parkinsonism-related chronic sequelae. The current systematic review is focused on a recent question aroused during the pandemic’s successive waves: are there post-SARS-CoV-2 immune-mediated reactions responsible for promoting neurodegeneration? Does the host’s dysregulated immune counter-offensive contribute to the pathogenesis of neurodegenerative diseases, emerging as Parkinson’s disease, in a complex interrelation between genetic and epigenetic risk factors? A synthetic and systematic literature review was accomplished based on the ”Preferred Reporting Items for Systematic Principles Reviews and Meta-Analyses” (PRISMA) methodology, including registration on the specific online platform: International prospective register of systematic reviews—PROSPERO, no. 312183. Initially, 1894 articles were detected. After fulfilling the five steps of the selection methodology, 104 papers were selected for this synthetic review. Documentation was enhanced with a supplementary 47 bibliographic resources identified in the literature within a non-standardized search connected to the subject. As a final step of the PRISMA method, we have fulfilled a Population-Intervention-Comparison-Outcome-Time (PICOT)/Population-Intervention-Comparison-Outcome-Study type (PICOS)—based metanalysis of clinical trials identified as connected to our search, targeting the outcomes of rehabilitative kinesitherapeutic interventions compared to clinical approaches lacking such kind of treatment. Accordingly, we identified 10 clinical trials related to our article. The multi/interdisciplinary conventional therapy of Parkinson’s disease and non-conventional multitarget approach to an integrative treatment was briefly analyzed. This article synthesizes the current findings on the pathogenic interference between the dysregulated complex mechanisms involved in aging, neuroinflammation, and neurodegeneration, focusing on Parkinson’s disease and the acute and chronic repercussions of COVID-19. Time will tell whether COVID-19 neuroinflammatory events could trigger long-term neurodegenerative effects and contribute to the worsening and/or explosion of new cases of PD. The extent of the interrelated neuropathogenic phenomenon remains obscure, so further clinical observations and prospective longitudinal cohort studies are needed.

Skin-on-a-Chip Technology: Microengineering Physiologically Relevant In Vitro Skin Models

The increased demand for physiologically relevant in vitro human skin models for testing pharmaceutical drugs has led to significant advancements in skin engineering. One of the most promising approaches is the use of in vitro microfluidic systems to generate advanced skin models, commonly known as skin-on-a-chip (SoC) devices. These devices allow the simulation of key mechanical, functional and structural features of the human skin, better mimicking the native microenvironment. Importantly, contrary to conventional cell culture techniques, SoC devices can perfuse the skin tissue, either by the inclusion of perfusable lumens or by the use of microfluidic channels acting as engineered vasculature. Moreover, integrating sensors on the SoC device allows real-time, non-destructive monitoring of skin function and the effect of topically and systemically applied drugs. In this Review, the major challenges and key prerequisites for the creation of physiologically relevant SoC devices for drug testing are considered. Technical (e.g., SoC fabrication and sensor integration) and biological (e.g., cell sourcing and scaffold materials) aspects are discussed. Recent advancements in SoC devices are here presented, and their main achievements and drawbacks are compared and discussed. Finally, this review highlights the current challenges that need to be overcome for the clinical translation of SoC devices.

Management strategies of sexual dysfunctions in Parkinson's disease

Sexual dysfunctions (SD) are frequent and highly disabling nonmotor manifestations of Parkinson's disease (PD) but are also potentially treatable. Neurologists should actively discuss, recognize and treat sexual health issues as an integral part of the management of the disease. In this chapter, we provide recommendations for managing and treating both primary and secondary SD in PD. Many sexual problems can be, at least partially, improved by adjusting the treatment of motor, nonmotor symptoms and comorbidities. Although some treatments of primary SD are evidence-based, many therapeutic options have not been yet systematically studied in patients with PD. The development of new treatments and repurposing of existing remedies in patients with PD remain an unmet need.

Dopamine D2L receptor density influences the recruitment of β-arrestin2 and Gi1 induced by antiparkinsonian drugs

INTRODUCTION

Brain imaging studies have highlighted that the density of dopamine D₂ receptors markedly fluctuates across the stages of Parkinson's disease and in response to pharmacological treatment. Moreover, receptor density constitutes a molecular determinant for the signaling profile of D₂ receptor ligands. We therefore hypothesized that variations in receptor expression could influence D₂ receptor response to antiparkinsonian drugs, most notably with respect to the recruitment bias between G_i1 and β-arrestin2.

METHODS

The recruitment bias of dopamine, pramipexole, ropinirole, and rotigotine was examined using a nanoluciferase-based biosensor for probing the interactions of the D_2L receptor with either G_i1 or β-arrestin2. The characterization of the functional selectivity of these D₂ receptor agonists was performed at two distinct D_2L receptor densities by taking advantage of a cell model carrying an inducible system that enables the overexpression of the D_2L receptor when exposed to doxycycline.

RESULTS

A high receptor density oriented the balanced signaling profile of dopamine towards a preferential recruitment of G_i1. It also moderated the marked G_i1 and β-arrestin2 biases of pramipexole and rotigotine, respectively. At variance, the G_i1 bias of ropinirole appeared as not being influenced by D_2L receptor density.

CONCLUSIONS

Taken together, these observations highlight receptor density as a key driver of the signaling transducer recruitment triggered by antiparkinsonian agents. Moreover, given the putative beneficial properties of β-arrestin2 in promoting locomotion, this study provides molecular insights that position the arrestin-biased ligand rotigotine as a putatively more beneficial D₂ receptor agonist for the treatment of early and late Parkinson's disease.

Treatment paradigms in Parkinson's Disease and Covid-19

People with Parkinson's Disease (PwP) may be at higher risk for complications from the Coronavirus Disease 2019 (Covid-19) due to older age and to the multi-faceted nature of Parkinson's Disease (PD) per se, presenting with a variety of motor and non-motor symptoms. Those on advanced therapies may be particularly vulnerable. Taking the above into consideration, along with the potential multi-systemic impact of Covid-19 on affected patients and the complications of hospitalization, we are providing an evidence-based guidance to ensure a high standard of care for PwP affected by Covid-19 with varying severity of the condition. Adherence to the dopaminergic medication of PwP, without abrupt modifications in dosage and frequency, is of utmost importance, while potential interactions with newly introduced drugs should always be considered. Treating physicians should be cautious to acknowledge and timely address any potential complications, while consultation by a neurologist, preferably with special knowledge on movement disorders, is advised for patients admitted in non-neurological wards. Non-pharmacological approaches, including the patient's mobilization, falls prevention, good sleep hygiene, emotional support, and adequate nutritional and fluid intake, are essential and the role of telemedicine services should be strengthened and encouraged.

Implications of dopaminergic medication withdrawal in Parkinson's disease

The trajectory of the use of dopamine replacement therapy (DRT) in Parkinson's disease (PD) is variable and doses may need to be increased, but also tapered. The plan for dose adjustment is usually done as per drug information recommendations from the licensing bodies, but there are no clear guidelines with regards to the best practice regarding the tapering off schedule given sudden dose reductions of drugs such as dopamine agonists may have serious adverse consequences. A systematic literature search was, therefore, performed to derive recommendations and the data show that there are no controlled studies or evidence-based recommendations how to taper or discontinue PD medication in a systematic manner. Most of the data were available on the dopamine agonist withdrawal syndrome (DAWS) and we found only two instructions on how to reduce pramipexole and rotigotine published by the EMA. We suggest that based on the available data, levodopa, dopamine agonists (DA), and amantadine should not be discontinued abruptly. Abrupt or sudden reduction of DA or amantadine in particular can lead to severe life-threatening withdrawal symptoms. Tapering off levodopa, COMT inhibitors, and MAO-B inhibitors may worsen motor and non-motor symptoms. Based on our clinical experience, we have proposed how to reduce PD medication and this work will form the basis of a future Delphi panel to define the recommendations in a consensus.