Treatment of advanced stage patients with Parkinson's disease

Association analyses of apolipoprotein E genotypes and cognitive performance in patients with Parkinson's disease

BACKGROUND

Cognitive impairment is a common non-motor symptom of Parkinson's disease (PD). The apolipoprotein E (APOE) ε4 genotype increases the risk of Alzheimer's disease (AD). However, the effect of APOEε4 on cognitive function of PD patients remains unclear. In this study, we aimed to understand whether and how carrying APOEε4 affects cognitive performance in patients with early-stage and advanced PD.

METHODS

A total of 119 Chinese early-stage PD patients were recruited. Movement Disorder Society Unified Parkinson's Disease Rating Scale, Hamilton anxiety scale, Hamilton depression scale, non-motor symptoms scale, Mini-mental State Examination, Montreal Cognitive Assessment, and Fazekas scale were evaluated. APOE genotypes were determined by polymerase chain reactions and direct sequencing. Demographic and clinical information of 521 early-stage and 262 advanced PD patients were obtained from Parkinson's Progression Marker Initiative (PPMI).

RESULTS

No significant difference in cognitive performance was found between ApoEε4 carriers and non-carriers in early-stage PD patients from our cohort and PPMI. The cerebrospinal fluid (CSF) Amyloid Beta 42 (Aβ42) level was significantly lower in ApoEε4 carrier than non-carriers in early-stage PD patients from PPMI. In advanced PD patients from PPMI, the BJLOT, HVLT retention and SDMT scores seem to be lower in ApoEε4 carriers without reach the statistical significance.

CONCLUSIONS

APOEε4 carriage does not affect the cognitive performance of early-stage PD patients. However, it may promote the decline of CSF Aβ42 level and the associated amyloidopathy, which is likely to further contribute to the cognitive dysfunction of PD patients in the advanced stage.

Slurring of Speech and Lip Paresthesia: Symptoms of Levodopa End of Dose Wearing Off in Parkinson's Disease

The prolonged use of levodopa for treating Parkinson's disease is associated with motor and nonmotor complications. These include wearing-off, delayed-on, partial-on, no-on, and on-off phenomena. In the wearing-off effect, symptoms return before a patient's next scheduled dose of levodopa. Patients may present with motor, sensory, or autonomic fluctuations. In this report, we present a female patient experiencing numbness of lips and slurred speech as a symptom of wearing-off effect. The major differential for sudden numbness of lips and slurred speech includes transient ischemic attacks. Therefore, it is imperative to identify the cause of these episodes so that appropriate treatment can be initiated. Our patient underwent extensive cardiac and neurological investigations, the findings of which were unremarkable. Her symptoms were likely due to levodopa wearing-off. Her condition improved on changing her levodopa to a sustained release form with more frequent dosing along with the addition of ropinirole to her treatment regimen.

Parkinson's disease permanent care unit: managing the chronic-palliative interface

Background:

Parkinson’s disease (PD) eventually leads to severe functional decline and dependence. Specialized care units for PD patients in need of permanent care are lacking.

Methods:

Patients with severe PD are referred to the PD permanent care unit harboring 30 patients with specialized medical and health care provided by trained staff. Patients need to have intensive medical and care needs, and be no longer able to stay at home or at an ordinary institution. A written and continuously reviewed care plan is made for each patient at admission, with the overriding aim to preserve quality of life and optimize functionality.

Results:

After five years, the PD permanent care unit has cared for 70 patients (36 men and 34 women) with a mean age of 76.6 years and a mean duration of Parkinsonism of 11.8 years. Hoehn and Yahr severity of disease was 3.7, cognition was 25.3 (Mini-Mental State Examination), and the mean daily levodopa dose was 739 mg. The yearly fatality rate was seven, and the mean duration of stay was 26.9 months. Only five patients moved out from the unit.

Conclusion:

A specially designed and staffed care unit for Parkinsonism patients seems to fill a need for patients and caregivers, as well as for social and health care authorities. This model is sensitive to the changing needs and capacities of patients, ensuring that appropriate services are available in a timely manner. There was a rather short duration of patient stay and remaining life span after admission to the unit. Despite the chronic/palliative state of patients at the PD permanent care unit, there are many therapeutic options, with the overriding objective being to allow the patients to end their days in a professional and comfortable environment.

Reducing uncertainty in value-based pricing using evidence development agreements: the case of continuous intraduodenal infusion of levodopa/carbidopa (Duodopa®) in Sweden

BACKGROUND

Value-based pricing (VBP), whereby prices are set according to the perceived benefits offered to the consumer at a time when costs and benefits are characterized by considerable uncertainty and are then reviewed ex post, is a much discussed topic in pharmaceutical reimbursement. It is usually combined with coverage with evidence development (CED), a tool in which manufacturers are granted temporary reimbursement but are required to collect and submit additional health economic data at review. Many countries, including the UK, are signalling shifts in this direction. Several countries, including Sweden, have already adopted this approach and offer good insight into the benefits and pitfalls in actual practice.

OBJECTIVE

To describe VBP reimbursement decision making using CED in actual practice in Sweden.

METHODS

Decision making by The Dental and Pharmaceutical Benefits Agency (TLV) in Sweden was reviewed using a case study of continuous intraduodenal infusion of levodopa/carbidopa (Duodopa®) in the treatment of advanced Parkinson's disease (PD) with severe motor fluctuations.

RESULTS

The manufacturer of Duodopa® applied for reimbursement in late 2003. While the proper economic data were not included in the submission, TLV granted reimbursement until early 2005 to provide time for the manufacturer to submit a formal economic evaluation. The re-submission with economic data was considered inadequate to judge cost effectiveness, so TLV granted an additional extension of reimbursement until August 2007, at which time conclusive data were expected. The manufacturer initiated a 3-year, prospective health economic study and a formal economic model. Data from a pre-planned interim analysis of the data were loaded into the model and the cost-effectiveness ratio was the basis of the next re-submission. TLV concluded that the data were suitable for making a definite decision and that the drug was not cost effective, deciding to discontinue reimbursement for any new patients (current patients were unaffected). The manufacturer continued to collect data and to improve the economic model and re-submitted in 2008. New data and the improved model resulted in reduced uncertainty and a lower cost-effectiveness ratio in the range of Swedish kronor (SEK)430,000 per QALY gained in the base-case analysis, ranging up to SEK900,000 in the most conservative sensitivity analysis, resulting in reimbursement being granted.

DISCUSSION

The case of Duodopa® provides excellent insight into VBP reimbursement decision making in combination with CED and ex post review in actual practice. Publicly available decisions document the rigorous, time-consuming process (four iterations were required before a final decision could be reached). The data generated as part of the risk-sharing agreement proved correct the initial decision to grant limited coverage despite lack of economic data. Access was provided to 100 patients while evidence was generated.

CONCLUSIONS

Economic appraisal differs from clinical assessment, and decision makers benefit from analysis of naturalistic, actual practice data. Despite reviewing the initial trial-based, 'piggy-back' economic analysis, TLV was uncertain of the cost effectiveness in actual practice and deferred a final decision until observational data from the DAPHNE study became available. Second, acceptance of economic modelling and use of temporary reimbursement conditional on additional evidence development provide a mechanism for risk sharing between TLV and manufacturers, which enabled patient access to a drug with proven clinical benefit while necessary evidence to support claims of cost effectiveness could be generated.

Shortness of breath, a 'wearing-off' symptom in Parkinson's disease

Although levodopa is considered the gold standard for Parkinson's disease therapy, prolonged use of this drug can result in motor complications such as a 'wearing-off' phenomenon. This outcome is seen in a significant number of patients with Parkinson's disease taking levodopa and, in some cases, is observed only a few hours after intake of the last dose of levodopa. Patients experiencing the wearing-off period may present with sensory, autonomic, psychiatric and motor fluctuations. Although infrequent, shortness of breath is an important non-motor wearing-off symptom experienced by patients with Parkinson's disease. In addition to being a symptom induced by wearing off, other causes of shortness of breath include pulmonary diseases, coronary artery disease and anxiety. Thus, it is important to identify the cause of shortness of breath to ensure that the appropriate treatment is initiated. We report here on a patient with Parkinson's disease who was taking levodopa and developed both shortness of breath and hyperventilation during wearing-off periods. He underwent extensive pulmonary and cardiac investigations that were unremarkable. His shortness of breath was determined to be a wearing-off phenomenon and his condition improved with the addition of a catechol-O-methyltransferase inhibitor (entacapone).

Advances in the treatment of Parkinson's disease

Parkinson's disease (PD) affects one in every 100 persons above the age of 65 years, making it the second most common neurodegenerative disease after Alzheimer's disease. PD is a disease of the central nervous system that leads to severe difficulties with body motions. The currently available therapies aim to improve the functional capacity of the patient for as long as possible; however they do not modify the progression of the neurodegenerative process. The need for newer and more effective agents is consequently receiving a great deal of attention and consequently being subjected to extensive research. This review concisely compiles the limitations of currently available therapies and the most recent research regarding neuroprotective agents, antioxidants, stem cell research, vaccines and various surgical techniques available and being developed for the management of PD.

Community and Long-Term Care Management of Parkinson???s Disease in the Elderly

Parkinson's disease affects up to 1 million people in the US, most of them elderly. Motor and non-motor symptoms can be significantly disabling to the point of necessitating institutionalisation. Age-related changes in drug absorption, distribution, metabolism and excretion complicate the treatment of elderly patients with Parkinson's disease. General management principles include initiation of medication at low doses with gradual titration based on clinical effects, avoidance of certain classes of drugs (e.g. anticholinergics), and attention to polypharmacy and its risk for potentially toxic drug interactions. Levodopa remains the most efficacious anti-Parkinson's disease medication and should be the cornerstone of therapy in the elderly Parkinson's disease patient. Use of dopamine receptor agonists, amantadine and anticholinergic drugs in the elderly is limited by high risk for psychotoxicity. Catechol-O-methyltransferase inhibitors may be used to augment levodopa in the setting of 'wearing off' (i.e. motor fluctuations). Monoamine oxidase type B (MAO-B) inhibitors can be used across the spectrum of disease severity, but selegiline (deprenyl), the prototype in this class, is characterised by low and erratic bioavailability of the parent drug and conversion to amphetamine metabolites that may increase the risk of adverse events. A new orally disintegrating tablet formulation overcomes some of these limitations. Rasagiline is a new, selective, second-generation MAO-B inhibitor that is chemically and metabolically distinct from selegiline. The favourable safety profile of rasagiline in the elderly and its once-daily formulation may maximise drug adherence and improve outcomes.

Reduced plasma homocysteine levels in levodopa/entacapone treated Parkinson patients

Hyperhomocysteinemia is not only a major risk factor for atherothrombotic disease, but is also strongly associated with an increased risk of dementia and cognitive impairment, both of which are common in the course of Parkinson's disease (PD). Previous work has found that levodopa increases plasma homocysteine concentrations. Animal studies have indicated that the catechol-O-methyltransferase (COMT) inhibitors can prevent levodopa-induced elevation of homocysteine concentrations by reducing the O-methylation of levodopa. The objective of our study was to assess the impact of entacapone, a COMT inhibitor, on plasma levels of homocysteine, serum folate, and vitamin B12 in levodopa-treated PD patients. Nineteen PD patients receiving only levodopa and 21 PD patients on a combination of levodopa and entacapone participated in the cross-sectional study. The control group consisted of 17 subjects on dopamine agonists. The mean plasma homocysteine concentration in the subjects on only levodopa was higher than that in the subjects on a combination of levodopa and entacapone (P=0.001) or in the control group (P=0.0001). Concentrations of serum vitamin B12 and serum folate were on average normal in all groups, but levodopa-treated subjects (with or without entacapone therapy) were more prone to have hypovitaminosis B12 (45%) than controls on dopamine agonists (6%). We suggest that the COMT inhibition may play a promising role in successfully controlling levodopa-induced hyperhomocysteinemia and in reducing the risk of pathologies probably linked to it. These preliminary findings and postulated hypotheses must now be confirmed in prospective studies.

Zydis selegiline reduces off time in Parkinson's disease patients with motor fluctuations: a 3-month, randomized, placebo-controlled study

Zydis selegiline dissolves on contact with saliva and undergoes pregastric absorption. This minimizes first-pass metabolism and provides high plasma concentrations of selegiline. In this study, the efficacy and safety of Zydis selegiline was assessed in Parkinson's disease (PD) patients who were experiencing motor fluctuations with levodopa. Patients were randomly assigned to either drug or placebo in a 2:1 ratio in this double-blind, multicenter trial. Significant reductions in daily off time occurred at 4 to 6 weeks with the 1.25 mg dose (9.9%, P = 0.003) and 10 to 12 weeks with the 2.5 mg dose (13.2%, P < 0.001). The total number of off hours was reduced by 2.2 hours at Week 12 from baseline (compared with 0.6 hours in the placebo group). The average number of dyskinesia-free on hours for the Zydis selegiline patients increased by 1.8 hours at Week 12. There was no change in mean percentage of "Asleep" time throughout the study. No apparent differences were detected in the occurrence of drug-related adverse events between the Zydis selegiline group and placebo-treated groups. Adverse events were consistent with known effects of levodopa therapy. Zydis selegiline safely reduces daily off time when used as adjunctive therapy with levodopa in patients with PD.

Hepatotoxic profile of catechol-O-methyltransferase inhibitors in Parkinson's disease

Entacapone and tolcapone are selective catechol-O-methyltransferase (COMT) inhibitors developed recently as adjuncts to levodopa for the treatment of Parkinson's disease (PD). They extend the duration of action of levodopa. As a result, they increase 'on' time, decrease 'off' time and improve motor scores in patients with motor fluctuations. Both benefits and main side effects are related to increased dopaminergic activity. This paper reviews the use of those COMT inhibitors in PD with particular focus on the issue of hepatotoxicity. Neither tolcapone nor entacapone caused hepatotoxicity in preclinical studies. However, in 1998, four patients who were using tolcapone presented with serious liver dysfunction; three of them died due to acute liver failure. Tolcapone is now known to have the potential to cause hepatotoxicity in clinical use and experimental studies. It is now recommended that tolcapone be administered only in patients with motor fluctuations who are no longer satisfactorily treated with other medications for PD. Routine liver monitoring is now mandatory with this agent. Entacapone has been described as a well-tolerated and safe drug in recent experimental studies, human clinical trials and postmarketing surveillance. It can be offered to any patient with motor fluctuations and routine liver monitoring is not required.