Discontinuation of ropinirole and pramipexole in patients with Parkinson's disease: clinical practice versus clinical trials

Long-term Apomorphine Infusion Users Versus Short-term Users: An International Dual-center Analysis of the Reasons for Discontinuing Therapy

OBJECTIVES

A retrospective analysis at 2 specialist centers was undertaken to determine the long-term efficacy of subcutaneous apomorphine infusion (APO), rates and reasons for discontinuation, and factors that might contribute to discontinuation.

METHODS

Demographics, clinical outcomes data, and reasons for discontinuation were collected for patients treated with APO at Chulalongkorn Centre of Excellence for Parkinson's Disease and Related Disorders, Bangkok, Thailand (n = 36) and Fundacion Jimemez Diaz Universidad Autonoma de Madrid, Spain (n = 16).

RESULTS

There were 19 (52.7%) patients in the Thai cohort and 10 (62.5%) patients in the Spanish cohort who discontinued treatment within around 6 months of initiation, most commonly due to skin nodules (Thai cohort) and perceived lack of efficacy (Spanish cohort). Those who continued APO tended to stay on treatment. In both cohorts, APO resulted in significant reductions in Unified Parkinson's Disease Rating Scale 3 motor scores, daily OFF time, and levodopa-equivalent dose in patients who subsequently stopped therapy, suggesting APO is clinically effective even when "lack of efficacy" is stated as a reason for discontinuing. Daily OFF hours after APO therapy was found to be a significant predictive factor for APO discontinuation with an odds ratio of 5.952 (P = 0.040). The cutoff point that determined APO discontinuation was calculated to be 1.75 or more OFF hours (sensitivity, 84.6%; specificity, 63.2%).

CONCLUSIONS

Apomorphine infusion is a minimally invasive therapy and therefore very easy to discontinue if difficulties arise. This fact might explain the high dropout rate of this technique. Successful long-term adherence to APO therapy requires a multidisciplinary health care team approach including regular patient follow-up and assessment and prompt resolution of queries and concerns.

Genetics and Treatment Response in Parkinson's Disease: An Update on Pharmacogenetic Studies

Parkinson's disease (PD) is a complex neurodegenerative disorder characterized by a progressive loss of dopamine neurons of the central nervous system. The disease determines a significant disability due to a combination of motor symptoms such as bradykinesia, rigidity and rest tremor and non-motor symptoms such as sleep disorders, hallucinations, psychosis and compulsive behaviors. The current therapies consist in combination of drugs acting to control only the symptoms of the illness by the replacement of the dopamine lost. Although patients generally receive benefits from this symptomatic pharmacological management, they also show great variability in drug response in terms of both efficacy and adverse effects. Pharmacogenetic studies highlighted that genetic factors play a relevant influence in this drug response variability. In this review, we tried to give an overview of the recent progresses in the pharmacogenetics of PD, reporting the major genetic factors identified as involved in the response to drugs and highlighting the potential use of some of these genomic variants in the clinical practice. Many genes have been investigated and several associations have been reported especially with adverse drug reactions. However, only polymorphisms in few genes, including DRD2, COMT and SLC6A3, have been confirmed as associated in different populations and in large cohorts. The identification of genomic biomarkers involved in drug response variability represents an important step in PD treatment, opening the prospective of more personalized therapies in order to identify, for each person, the better therapy in terms of efficacy and toxicity and to improve the PD patients' quality of life.

Patient and Public Preferences for Treatment Attributes in Parkinson's Disease

Background

Patient and public preferences for therapeutic outcomes or medical technologies are often elicited, and discordance between the two is frequently reported.

Objective

Our main objective was to compare patient and public preferences for treatment attributes in Parkinson’s disease (PD).

Methods

A representative sample from Dutch PD patients and the general public were invited to complete a best–worst scaling case 2 experiment consisting of six health-related outcomes and one attribute describing the specific treatment (brain surgery, pump, oral medication). Data were analyzed using mixed logit models, and attribute impact was estimated and compared between populations (and population subgroups).

Results

Both the public (N = 276) and patient (N = 198) populations considered treatment modality the most important attribute, although patients assigned higher relative importance. Both groups assigned high disutility to pump infusion and brain surgery and preferred drug treatment. Most health outcomes were valued equally by patients and the public, with the exception of reducing dizziness (more important to the public) and improving slow movement (more important to patients).

Discussion

Although these data do not support definite conclusions on whether patients are less likely to undergo invasive treatments, the (predicted) choice probability of undergoing brain surgery or having pump infusion technology would be low based on the (un)desirability of the attribute levels. Patients with PD might have adapted to their condition and are not willing to undergo advanced treatments in order to receive health improvements. Both public and patient preferences entail information that is potentially relevant for decision makers, and patient preferences can inform decision makers about the likelihood of adaptation to a specific condition.

Electronic supplementary material

The online version of this article (doi:10.1007/s40271-017-0247-7) contains supplementary material, which is available to authorized users.

Involving Patients in Weighting Benefits and Harms of Treatment in Parkinson's Disease

Introduction

Little is known about how patients weigh benefits and harms of available treatments for Parkinson’s Disease (oral medication, deep brain stimulation, infusion therapy). In this study we have (1) elicited patient preferences for benefits, side effects and process characteristics of treatments and (2) measured patients’ preferred and perceived involvement in decision-making about treatment.

Methods

Preferences were elicited using a best-worst scaling case 2 experiment. Attributes were selected based on 18 patient-interviews: treatment modality, tremor, slowness of movement, posture and balance problems, drowsiness, dizziness, and dyskinesia. Subsequently, a questionnaire was distributed in which patients were asked to indicate the most and least desirable attribute in nine possible treatment scenarios. Conditional logistic analysis and latent class analysis were used to estimate preference weights and identify subgroups. Patients also indicated their preferred and perceived degree of involvement in treatment decision-making (ranging from active to collaborative to passive).

Results

Two preference patterns were found in the patient sample (N = 192). One class of patients focused largely on optimising the process of care, while the other class focused more on controlling motor-symptoms. Patients who had experienced advanced treatments, had a shorter disease duration, or were still employed were more likely to belong to the latter class. For both classes, the benefits of treatment were more influential than the described side effects. Furthermore, many patients (45%) preferred to take the lead in treatment decisions, however 10.8% perceived a more passive or collaborative role instead.

Discussion

Patients weighted the benefits and side effects of treatment differently, indicating there is no “one-size-fits-all” approach to choosing treatments. Moreover, many patients preferred an active role in decision-making about treatment. Both results stress the need for physicians to know what is important to patients and to share treatment decisions to ensure that patients receive the treatment that aligns with their preferences.

Causes and factors related to dopamine agonist withdrawal in Parkinson's disease

BACKGROUND

Although dopamine agonists (DAs) are useful in Parkinson's disease (PD), they are not frequently used in elderly patients due to adverse effects. However, there is a lack of evidence because few elderly PD patients are enrolled in clinical trials.

AIMS OF THE STUDY

The aims of this study were to analyze the reasons of DA withdrawal (DAW) in a group of PD patients in clinical practice and to identify the related factors. Specifically, we studied the effect of age, comorbidity, and polypharmacy as potential risk factors for DAW.

METHODS

A retrospective chart review of the follow-up (from May, 2012 to March, 2015) of a subgroup of PD patients receiving a DA (n = 68; 60.3% males, 69.3 ± 9.2 years old) from a cohort (n = 150) previously studied in detail in 2012 was used to identify predictive factors of DAW.

RESULTS

The DAW percentage was 18.2% (12/66; follow-up of 690.2 ± 232.6 days). DAW causes were cognitive impairment (3), reduction therapy (3), hallucinations (2), dyskinesia (2), and excessive diurnal somnolence (2). Only a higher levodopa daily dose (HR 1.003; 95% CI 1.001-1.006; P = 0.044) was an independent predictor of DAW after adjustment for other explanatory variables.

CONCLUSIONS

The frequency of DAW was low. Advanced age alone is not a contraindication to the administration of DAs.

Duration of L-dopa and dopamine agonist monotherapy in Parkinson's disease

The expected duration of initial antiparkinson monotherapy before the need for supplementation is not clearly defined for routine practice. The aim of this study was to define the length of L-dopa (L-3, 4-dihydrophenylalanine) and dopamine agonist monotherapy. The duration of monotherapy and discontinuation rates were investigated in a natural observational setting by plotting Kaplan-Meier survival curves. Out of 345 patients, 180 (52.2%) received L-dopa and 165 (47.8%) received a dopamine agonist as initial monotherapy. Half of the patients starting L-dopa received supplementary therapy with- in 3.6 years (95% confidence interval, 3.2-4.6), significantly longer than for dopamine agonist monotherapy (half required a second agent at 2.3 years [2.0-2.9]; P = 0.00017). Discontinuation of L-dopa therapy was 1%. Dopamine agonists were stopped (due to side-effects like impulse control disorders [6%], somnolence [4%] and light-headedness [3%]) in 20% over four years. The duration and tolerability of L-dopa and dopamine agonists as initial Parkinson's disease monotherapy are defined in this study; this may form part of the information exchange with patients.

Clinical and pharmacogenetic determinants for the discontinuation of non-ergoline dopamine agonists in Parkinson's disease

Objective

To identify determinants for the discontinuation of non-ergoline dopamine agonist (DA) treatment in patients with Parkinson’s disease (PD) and to identify genetic determinants in genes encoding dopamine receptor (DR)D2 and DRD3 in a exploratory analysis.

Methods

Patients included were first-time users of the non-ergoline DA ropinirole or pramipexole who had been diagnosed with PD before 2005. Treatment discontinuation was defined as a gap of 180 days or more between two refills of the DA. Non-genetic determinants for discontinuation were studied in the overall population, and genetic determinants [DRD2 141C Ins/Del, DRD2 (CA)_n STR, DRD2 TaqIA, DRD3 MscI single nucleotide polymorphism (SNP) and DRD3 MspI SNP] were studied in a subgroup. Cox proportional hazard analysis was used to estimate the hazard ratios (HR) for the discontinuation of non-ergoline DA treatment.

Results

The study population comprised 90 patients. Apomorphine use was associated with non-ergoline DA discontinuation, although the apomorphine group consisted only of three patients [HR 6.26; 95% confidence interval (CI) 1.85–21.2]. Daily levodopa dosages between 500 and 1000 mg were positively associated with discontinuation (HR 2.31; 95% CI 1.08–4.93). Included in the exploratory pharmacogenetic analysis were 38 patients. The absence of a 15× DRD2 CA repeat allele was significantly related with a decreased discontinuation of non-ergoline treatment (HR 0.23; 95% CI 0.07–0.81). The DRD3 MspI polymorphism showed a non-significant allele dose effect, suggestive of a causal relationship.

Conclusion

This study identified apomorphine use and levodopa dosages between 500 and 1000 mg as non-genetic and the 15× DRD2 CA repeat allele as genetic determinants for the discontinuation of non-ergoline DA treatment in patients with PD. More research is needed to replicate these findings.

Socio-demographic and clinical factors influencing the adherence to treatment in Parkinson's disease: the ADHESON study

BACKGROUND

Symptoms of Parkinson's disease (PD) are usually controlled by a continuous titration of medication and addition of multiple therapies over the course of the disease. Therapeutic complex schemes, polymedication, comorbidities and the number of medications required contribute to non-adherence.

METHODS

This cross-sectional survey was performed in 418 patients with PD on treatment with any antiparkinsonian medication. Patient adherence was assessed through physicians' subjective perception and the Morisky-Green test (MGT). Several social, demographic and clinical features were correlated through bivariate and multivariate analyses.

RESULTS

According to the physician's opinion 93.7%, and according to the MGT 60.4% of patients were adherent to parkinsonian therapy. The bivariate analysis showed greater adherence in patients with a high level of knowledge about the disease (62.8%), good clinical control (63.6%), a spouse or life partner (63%) and higher incomes (66%). Negative correlation with psychiatric symptoms was found. In relation to the MGT, the logistic regression model showed a negative correlation between cognitive deterioration and psychiatric pathology and adherence to therapy.

CONCLUSIONS

The physician's impression overestimated the compliance of patients when compared with an objective evaluation such as the MGT. Cognitive impairment and psychiatric symptoms are the clinical variables associated with a lower level of adherence.