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Over half of Parkinson's disease (PD) patients develop psychotic symptoms, and PD psychosis (PDP) is associated with significant distress to patients, caregiver burden, and impairs quality of life. Pharmacological therapy is limited to atypical antipsychotics.This review will summarize efficacy but will focus on the safety of antipsychotics for treating PDP, and in particular the off-target safety issues including cognitive impairment, sleep disturbance, cardiovascular effects, and motor function.Pimavanserin is the only medication approved in the US for treating PDP, however clozapine is also considered efficacious. Despite lack of substantial evidence for efficacy, quetiapine is commonly used to treat PDP. Despite the effectiveness of pimavanserin and clozapine for treating PDP, a need exists for additional pharmacological agents that are effective for PDP while providing an acceptable safety and tolerability profile. Medications to treat PDP should avoid worsening motor function, and also minimize sleep disturbances, cognitive impairment, cardiovascular effects, and other non-motor safety concerns. A neutral effect or reduction in mortality risk associated with PD and PDP would be ideal, and low rate of discontinuation due to AEs is desirable. Lastly, medications that can be used safely in combination with other pharmacological agents is essential.

Immediate-release (IR) amantadine has been used for treatment of levodopa induced dyskinesia (LID). The immediate-release/extended-release (IR/ER) amantadine formulation OS320 (OSMOLEX ER®) contains an IR outer layer and ER core for once-daily dosing.Report individual and pooled results for the similarly designed double-blind, placebo-controlled ALLAY-LID I and II trials, assessing IR/ER-amantadine for LID.PD patients with LID were randomized to IR/ER-amantadine 193 mg, 258 mg, or placebo. Primary endpoint was Unified Dyskinesia Rating Scale (UDysRS) score change from baseline to Day 98. Secondary outcome was ON time without troublesome dyskinesia based on diaries. Exploratory outcomes were other diary states (including OFF), MDS-UPDRS Parts II + III and Fatigue Severity Scale.Overall, 222 individuals enrolled (N = 87 ALLAY-LID I, N = 135 ALLAY-LID II); both trials terminated early for sponsor's decision. While ALLAY-LID I did not meet its primary endpoint, a significant reduction in UDysRS scores versus placebo was observed in ALLAY-LID II for both 193 mg and 258 mg doses. In the pooled analysis, placebo-adjusted UDysRS score differences were -5.5 [-9.8, -1.2], p = 0.012 and -5.2 [-9.5, -0.9], p = 0.017, respectively. IR/ER-amantadine 258 mg significantly increased time spent ON without troublesome dyskinesia in ALLAY-LID II and pooled analysis. Reductions in ON time with dyskinesia supported the primary outcome. There was no effect on OFF time or other outcomes. Overall, 13.3% (193 mg), 18.7% (258 mg) and 11.1% (placebo) discontinued for adverse events, most commonly hallucinations (4.0%, 10.7%, and 1.4%, respectively).IR/ER-amantadine significantly reduced LID in ALLAY-LID II but not in ALLAY-LID I; post-hoc pooled data also indicated a positive treatment effect on LID.

Neurogenic orthostatic hypotension (NOH) is an orphan disease that primarily affects patients with neurodegenerative disorders such as Parkinson's disease and multiple system atrophy. The first step in the management of NOH is to discontinue or minimize the use of drugs that lower blood pressure. Nonpharmacologic therapy for NOH includes physical countermaneuvers, compression abdominal binders and lower extremity stockings, recognition and avoidance of orthostatic stressors, hydration, and salt supplementation. The management of NOH should also include interventions to prevent falls. Pharmacotherapy for NOH includes the mineralocorticoid drug fludrocortisone to expand plasma volume and the sympathomimetic drugs midodrine and droxidopa. Clinical efficacy, tolerability, and the role of each drug in the treatment paradigm are reviewed here.

Neurogenic orthostatic hypotension (nOH) is due to failure of the autonomic nervous system to regulate blood pressure in response to postural changes due to an inadequate release of norepinephrine, leading to orthostatic hypotension and supine hypertension. nOH is common in Parkinson’s disease (PD). Prevalence varies throughout the course of PD, ranging from 40% to 60%, and resulting in symptomatic nOH in approximately half. Symptomatic nOH, including lightheadedness, can limit daily activities and lead to falls. Symptomatic nOH can also limit therapeutic options for treating PD motor symptoms. Clinical evaluation should routinely include symptom assessment and blood pressure measurement of supine, sitting, and 3-minute standing; 24-hour ambulatory blood pressure monitoring can also be helpful. Non-pharmacological management of symptomatic nOH involves education, physical maneuvers, and adequate hydration. Current pharmacological treatment of symptomatic nOH includes salt supplement, fludrocortisone, midodrine, pyridostigmine, and other empiric medications. Despite these options, treatment of symptomatic nOH remains suboptimal, often limited by severe increases in supine blood pressure. Droxidopa, an oral prodrug converted by decarboxylation to norepinephrine, is a promising therapeutic option for symptomatic nOH in PD, improving symptoms of nOH, daily activities, falls, and standing systolic blood pressure in several recent trials. These trials demonstrated short-term efficacy and tolerability, with comparable increases in standing and supine blood pressures. Longer-term studies are ongoing to confirm durability of treatment effect.

Objective To evaluate the possible association of Parkinson disease (PD) and melanoma in North America. Design, Setting, and Patients Thirty-one centers enrolled patients with idiopathic PD. At visit 1, a neurologist obtained a medical history. At visit 2, a dermatologist recorded melanoma risk factors, performed a whole-body examination, and performed a biopsy of lesions suggestive of melanoma for evaluation by a central dermatopathology laboratory. We compared overall prevalence of melanoma with prevalence calculated from the US Surveillance Epidemiology and End Results (SEER) cancer database and the American Academy of Dermatology skin cancer screening programs. Results A total of 2106 patients (mean [SD] age, 68.6 [10.6] years; duration of PD, 7.1 [5.7] years) completed the study. Most (84.8%) had received levodopa. Dermatology examinations revealed 346 pigmented lesions; dermatopathological findings confirmed 20 in situ melanomas (0.9%) and 4 invasive melanomas (0.2%). In addition, histories revealed 68 prior melanomas (3.2%). Prevalence (5-year limited duration) of invasive malignant melanoma in the US cohort of patients with PD (n = 1692) was 2.24-fold higher (95% confidence interval, 1.21-4.17) than expected in age- and sex-matched populations in the US SEER database. Age- or sex-adjusted relative risk of any melanoma for US patients was more than 7 times that expected from confirmed cases in American Academy of Dermatology skin cancer screening programs. Conclusions Melanoma prevalence appears to be higher in patients with PD than in the general population. Despite difficulties in comparing other databases with this study population, the study supports increased melanoma screening in patients with PD.