ADS-5102 is a long-acting, extended-release capsule formulation of amantadine HCl administered once daily at bedtime. This study investigated the safety, efficacy, and tolerability of ADS-5102 in Parkinson's disease (PD) patients with levodopa-induced dyskinesia. This was a randomized, double-blind, placebo-controlled, parallel-group study of 83 PD patients with troublesome dyskinesia assigned to placebo or one of three doses of ADS-5102 (260 mg, 340 mg, 420 mg) administered daily at bedtime for 8 weeks. The primary efficacy analysis compared change from baseline to week 8 in Unified Dyskinesia Rating Scale (UDysRS) total score for 340 mg ADS-5102 versus placebo. Secondary outcome measures included change in UDysRS for 260 mg, 420 mg, Fatigue Severity Scale (FSS), Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), patient diary, Clinician's Global Impression of Change, and Parkinson's Disease Questionnaire (PDQ-39). ADS-5102 340 mg significantly reduced dyskinesia versus placebo (27% reduction in UDysRS, P = 0.005). In addition, ADS-5102 significantly increased ON time without troublesome dyskinesia, as assessed by PD patient diaries, at 260 mg (P = 0.004), 340 mg (P = 0.008) and 420 mg (P = 0.018). Adverse events (AEs) were reported for 82%, 80%, 95%, and 90% of patients in the placebo, 260-mg, 340-mg, and 420-mg groups, respectively. Constipation, hallucinations, dizziness, and dry mouth were the most frequent AEs. Study withdrawal rates were 9%, 15%, 14%, and 40% for the placebo, 260-mg, 340-mg, and 420-mg groups, respectively. All study withdrawals in the active treatment groups were attributable to AEs. ADS-5102 was generally well tolerated and resulted in significant and dose-dependent improvements in dyskinesia in PD patients.
OBJECTIVE: The AMANDYSK trial was designed to assess long-term efficacy of chronic treatment with amantadine in patients with Parkinson disease (PD) and levodopa-induced dyskinesia (LID). METHODS: This was a 3-month, multicenter, randomized, double-blind, placebo-controlled, parallel-group, wash-out study conducted in 57 amantadine-treated (>=200 mg/d for >=6 months) dyskinetic patients with PD. The primary outcome measure was the change from baseline in a Unified Parkinson's Disease Rating Scale (UPDRS) dyskinesia subscore (items 32 [duration] + 33 [severity]). Secondary outcomes included other LID measurements ('responders' analysis, premature dropout for LID, Abnormal Involuntary Movement Scale). Exploratory outcomes included time with troublesome dyskinesia as measured by diaries, UPDRS Motor Examination (part III) for motor symptoms of PD, and fatigue and apathy scores for nonmotor symptoms. RESULTS: UPDRS items 32 + 33 deteriorated more in patients switched to placebo ('discontinuing' group) (+1.7 ± 2.0 units; 95% confidence interval 0.9, 2.4) as compared with those maintained on amantadine ('continuing' group) (+0.2 ± 1.5 units; 95% confidence interval -0.4, 0.8; p = 0.003). Secondary outcomes confirmed this difference because there were significantly more responders, more dropouts for LID, greater increase in 'ON' time with troublesome dyskinesia, and greater worsening of Abnormal Involuntary Movement Scale score in the discontinuing group. There were no between-group differences in the UPDRS Motor Examination, whereas apathy (as measured by caregivers) and fatigue scores tended to worsen more in patients randomized to placebo. CONCLUSION: Wash-out of amantadine in dyskinetic patients with PD significantly worsened LID. No significant effect was observed on motor parkinsonian symptoms, while exploratory outcomes suggested that amantadine might improve apathy and fatigue in such patients. CLASSIFICATION OF EVIDENCE: This article provides Class II evidence that in patients with PD, withdrawing amantadine significantly aggravates LID in a median time of 7 days.
Numerous scales assess dyskinesia in Parkinson's disease (PD), variably focusing on anatomical distribution, phenomenology, time, severity, and disability. No study has compared these scales and their relative ability to detect change related to an established treatment. We conducted a randomized placebo-controlled trial of amantadine, assessing dyskinesia at baseline and at 4 and 8 weeks using the following scales: Unified Dyskinesia Rating Scale (UDysRS), Lang-Fahn Activities of Daily Living Dyskinesia Rating Scale (LF), 26-Item Parkinson's Disease Dyskinesia scale (PDD-26), patient diaries, modified Abnormal Involuntary Movements Scale (AIMS), Rush Dyskinesia Rating Scale (RDRS), dyskinesia items from the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS), and Clinical Global Impression (severity and change: CGI-S, CGI-C). Scale order was randomized at each visit, but raters were aware of each scale as it was administered. Sensitivity to treatment was assessed using effect size. Sixty-one randomized dyskinetic PD subjects (31 amantadine, 30 placebo) completed the study. Four of the 8 scales (CGI-C, LF, PDD-26, and UDysRS) detected a significant treatment. The UDysRS Total Score showed the highest effect size (η(2) = 0.138) for detecting treatment-related change, with all other scales having effect sizes < 0.1. No scale was resistant to placebo effects. This study resolves 2 major issues useful for future testing of new antidyskinesia treatments: among tested scales, the UDysRS, having both subjective and objective dyskinesia ratings, is superior for detecting treatment effects; and the magnitude of the UDysRS effect size from amantadine sets a clear standard for comparison for new agents.
BACKGROUND: Dyskinesias are some of the major motor complications that impair quality of life for patients with Parkinson's disease. The purpose of the present study was to investigate the efficacy of amantadine in Parkinson's disease patients suffering from dyskinesias.
METHODS: In this multi-center, double-blind, randomized, placebo-controlled, cross-over trial, 36 patients with Parkinson's disease and dyskinesias were randomized, and 62 interventions, which included amantadine (300 mg/day) or placebo treatment for 27 days, were analyzed. At 15 days after washout, the treatments were crossed over. The primary outcome measure was the changes in the Rush Dyskinesia Rating Scale (RDRS) during each treatment period. The secondary outcome measures were changes in the Unified Parkinson's Disease Rating Scale part IVa (UPDRS-IVa, dyskinesias), part IVb (motor fluctuations), and part III (motor function).
RESULTS: RDRS improved in 64% and 16% of patients treated with amantadine or placebo, respectively, with significant differences between treatments. The adjusted odds-ratio for improvement by amantadine was 6.7 (95% confidence interval, 1.4 to 31.5). UPDRS-IVa was improved to a significantly greater degree in amantadine-treated patients [mean (SD) of 1.83 (1.56)] compared with placebo-treated patients [0.03 (1.51)]. However, there were no significant effects on UPDRS-IVb or III scores.
CONCLUSIONS: Results from the present study demonstrated that amantadine exhibited efficacious effects against dyskinesias in 60-70% of patients.
TRIAL REGISTRATION: UMIN Clinical Trial Registry UMIN000000780.
We evaluated the effects of amantadine on levodopa-induced dyskinesia (LID) in eighteen consecutive Parkinson's disease (PD) patients in a randomized, double-blind, placebo-controlled study. The primary outcomes were the Clinical Dyskinesia Rating Scale (CDRS) and the Unified Parkinson's Disease Rating Scale (UPDRS) part IVa score changes. The secondary outcomes were the UPDRS II and III score changes. Amantadine did not change the CDRS score for hyperkinesia or dystonia, but decreased the duration of LID and its influence on daily activities (p=0.04) and the UPDRS II score (p=0.01) more than placebo. These findings show that amantadine reduces the duration of LID and improves motor disability in PD.
BACKGROUND: Recent short-term studies suggested that amantadine (Ama) might ameliorate dyskinesia in patients with Parkinson's disease. A double-blind study programmed over 12 months was designed to assess the duration of the antidyskinetic effect of amantadine on levodopa induced dyskinesia.
METHODS: 40 patients treated for 7.5 (2.2) years with levodopa (729.3 (199.4) mg/day) and dopaminoagonists, having peak dose or dyphasic dyskinesia with or without pain, were assessed with the Unified Parkinson's Disease Rating Scale subscale IV, Items 32-34, the Dyskinesia Rating Scale and Investigator Global Assessment. Twenty patients received amantadine chloridrate (100 mg) and 20 received a placebo. The Ama or placebo could be withdrawn when scores indicated worsening of dyskinesia, after agreement with the patient.
RESULTS: After 15 days of amantadine treatment there was a reduction by 45% in the total dyskinesia scores. All patients in the placebo group were withdrawn in 1-3 months and all patients in the Ama group were withdrawn in 3-8 months (p = 0.01, p<0.001). Ama withdrawal induced a rebound with increase of dyskinesia by 10-20% in 11 patients.
CONCLUSION: 300 mg amantadine reduces dyskinesia in Parkinson's disease by approximately 45% but the benefit lasted less than eight months.
Experimental evidence suggests that glutamatergic receptor blockade may improve the motor response complications associated with long-term levodopa treatment in Parkinson's disease (PD) patients. Our objective was to evaluate the acute effect of amantadine, a noncompetitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, on levodopa-induced dyskinesias, and to gain further insights into the antidyskinetic mechanism of this drug. Nine PD patients with motor fluctuations and severely disabling peak of dose dyskinesias received their first morning levodopa dose, followed by a 2-hour intravenous amantadine (200 mg) or placebo infusion, on two different days. Parkinsonian symptoms and dyskinesias were assessed every 15 minutes during the infusion and for 3 hours thereafter, while patients were taking their usual oral antiparkinsonian therapy, by means of Unified Parkinson's Disease Rating Scale (UPDRS, motor examination), tapping test, and a modified Abnormal Involuntary Movement Scale (AIMS). Intravenous amantadine acutely improved levodopa-induced dyskinesias by 50%without any loss of the anti-parkinsonian benefit from levodopa. This study confirms the antidyskinetic effect of amantadine and strengthens the rationale for using antiglutamatergic drugs in the treatment of parkinsonian motor fluctuations.
We performed a double-blind, placebo-controlled, crossover study to assess the effect of amantadine versus placebo on levodopa-induced dyskinesias in Parkinson's disease. We found a 24% reduction in the total dyskinesia score after amantadine administration (p = 0.004). This improvement was achieved without any influence on the severity of "on" period parkinsonism. The results confirm that amantadine reduces levodopa dyskinesias and support the hypothesis that dyskinesias can be reduced by blockade of excitatory pathways in the basal ganglia.
ADS-5102 is a long-acting, extended-release capsule formulation of amantadine HCl administered once daily at bedtime. This study investigated the safety, efficacy, and tolerability of ADS-5102 in Parkinson's disease (PD) patients with levodopa-induced dyskinesia. This was a randomized, double-blind, placebo-controlled, parallel-group study of 83 PD patients with troublesome dyskinesia assigned to placebo or one of three doses of ADS-5102 (260 mg, 340 mg, 420 mg) administered daily at bedtime for 8 weeks. The primary efficacy analysis compared change from baseline to week 8 in Unified Dyskinesia Rating Scale (UDysRS) total score for 340 mg ADS-5102 versus placebo. Secondary outcome measures included change in UDysRS for 260 mg, 420 mg, Fatigue Severity Scale (FSS), Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), patient diary, Clinician's Global Impression of Change, and Parkinson's Disease Questionnaire (PDQ-39). ADS-5102 340 mg significantly reduced dyskinesia versus placebo (27% reduction in UDysRS, P = 0.005). In addition, ADS-5102 significantly increased ON time without troublesome dyskinesia, as assessed by PD patient diaries, at 260 mg (P = 0.004), 340 mg (P = 0.008) and 420 mg (P = 0.018). Adverse events (AEs) were reported for 82%, 80%, 95%, and 90% of patients in the placebo, 260-mg, 340-mg, and 420-mg groups, respectively. Constipation, hallucinations, dizziness, and dry mouth were the most frequent AEs. Study withdrawal rates were 9%, 15%, 14%, and 40% for the placebo, 260-mg, 340-mg, and 420-mg groups, respectively. All study withdrawals in the active treatment groups were attributable to AEs. ADS-5102 was generally well tolerated and resulted in significant and dose-dependent improvements in dyskinesia in PD patients.
