Dopamine agonists are used as initial treatment in patients with Parkinson's disease (PD) to reduce incidence and severity of motor complications. This paradigm is based on long-term studies, allowing "rescue" therapy with levodopa. The present strict monotherapy study (PELMOPET, the acronym for the pergolide-versus-L-dopa-monotherapy-and-positron-emission-tomography trial) evaluated the efficacy and safety of pergolide versus levodopa without levodopa "rescue" medication. This multicenter, double-blind, randomized, 3-year trial compared pergolide monotherapy (n=148) with levodopa monotherapy (n=146) in dopamine-naive patients with early PD (Hoehn and Yahr stage 1-2.5). Primary efficacy measures were clinical efficacy, severity and time to onset of motor complications, and disease progression. During the 3 years, severity of motor complications was significantly lower and time to onset of dyskinesia was significantly delayed in the group receiving pergolide (3.23 mg/day) compared with those receiving levodopa (504 mg/day). However, time to onset of motor complications was not longer in patients receiving pergolide after 3 years. Symptomatic relief (assessed by Unified Parkinson's Disease Rating Scale [UPDRS], UPDRS II, and III, Clinical Global Impressions [CGI] severity, and CGI and Patient Global Impressions [PGI] improvement) was significantly greater in patients receiving levodopa. Adverse events led to discontinuation of therapy in 17.6% of pergolide patients and 9.6% of levodopa patients. This is the first study comparing strict monotherapy with a dopamine agonist versus levodopa in previously untreated early PD. In principle, both levodopa and a dopamine agonist such as pergolide seem to be suitable options as initial PD therapy. The choice remains with the treating physician based on the different efficacy and adverse event profiles.
OBJECTIVES: Cabergoline is an ergoline derivative with a very long half-life that allows once-daily administration and the potential for more continuous stimulation of dopaminergic receptors than is possible with other dopamine receptor agonists (DAs). The aim of this study was to evaluate whether the possible advantage resulting from a more sustained dopaminergic effect of cabergoline would translate into delayed onset of motor complications, compared with levodopa, in patients with newly diagnosed Parkinson's disease.
STUDY DESIGN AND METHODS: This study was a double-blind, multicentre trial that compared cabergoline and levodopa as initial therapy for Parkinson's disease. A total of 419 levodopa-, DA- and selegiline-naive patients with newly diagnosed Parkinson's disease were randomised to receive either cabergoline (n = 211) or levodopa (n = 209). Treatment was titrated to an optimal dose over a period of up to 24 weeks and then continued at this dose until the study endpoint (confirmed motor complications) or up to a maximum of 5 years. At years 1-5, the cabergoline group was receiving cabergoline at average daily doses ranging from 2.8-2.9 mg, with added levodopa at mean daily doses ranging from 322 mg at year 1 to 431 mg at year 5; over the same period, the levodopa group was receiving daily levodopa doses of 784 mg. Thus, patients in the cabergoline group received <50% levodopa than patients in the levodopa group.
RESULTS: Motor complications were significantly delayed (p = 0.0175) and occurred less frequently in cabergoline-treated patients than in levodopa-treated patients (22.3% vs 33.7%). Cox model proportional hazards regression analysis showed that the relative risk of developing such complications was >50% lower (0.46; p < 0.001) in the cabergoline group compared with the levodopa group. In particular, development of dyskinesias was markedly delayed in the cabergoline group and occurred in 9.5% of patients compared with 21.2% in the levodopa group (p < 0.001). Among patients not requiring supplemental levodopa, the frequency of motor complications was three times higher with levodopa (15.5% of 110 patients) than with cabergoline (5.3% of 76 patients). Among patients who did need supplemental levodopa, motor complications were more frequent in the levodopa arm (54.1% of 98 patients) than in the cabergoline arm (31.9% of 135 patients). Consistent improvements relative to baseline in average Unified Parkinson's Disease Rating Scale (UPDRS) daily living activities and motor function sections, and in Clinical Global Impression severity of illness and physician- and patient- rated global improvement scores, were seen in both treatment groups, with maximal effects occurring within 2 years. However, levodopa treatment was associated with a significantly (p < 0.001) greater improvement in motor disability (as measured by the UPDRS motor score) over time, with mean values of 13.8 versus 12.9 in the cabergoline versus levodopa arm recorded at 1 year, 18.6 versus 17.2 at 3 years and 19.2 versus 16.3 at 5 years, respectively. While the overall frequency of adverse events was similar in the two groups, the cabergoline-treated group experienced marginally, but not significantly, higher frequencies of nausea, vomiting, dyspepsia and gastritis (37.4% vs 32.2% in the levodopa group) and of dizziness and postural hypotension (31.3% vs 24% in the levodopa group). Cabergoline-treated patients also experienced a significantly higher frequency of peripheral oedema (16.1% vs 3.4%, respectively; p < 0.0001). The cabergoline and levodopa groups had similar rates of sleepiness (17.5% vs 18.3%, respectively) and hallucinations (4.8% vs 4.4%, respectively); in an elderly population subset, hallucinations were reported in 7.1% and 6.5% of patients taking cabergoline and levodopa, respectively. Adverse events generally occurred more frequently in female patients (with the exception of dyskinesias, hyperkinesias and hallucinations, which occurred more frequently in men) and in the elderly.
CONCLUSION: This study showed that, compared with levodopa, initial therapy with cabergoline in patients with Parkinson's disease is associated with a lower risk of response fluctuations at the cost of a marginally reduced symptomatic improvement and some tolerability disadvantages that are mostly limited to a significantly higher frequency of peripheral oedema.
Preclinical studies suggest ropinirole may be neuroprotective in Parkinson's disease (PD), and a pilot clinical study using ¹⁸F-dopa positron emission tomography (PET) suggested a slower loss of striatal dopamine storage with ropinirole compared with levodopa. This prospective, 2-year, randomized, double-blind, multinational study compared the rates of loss of dopamine-terminal function in de novo patients with clinical and ¹⁸F-dopa PET evidence of early PD, randomized 1 to 1 to receive either ropinirole or levodopa. The primary outcome measure was reduction in putamen ¹⁸F-dopa uptake (Ki) between baseline and 2-year PET. Of 186, 162 randomized patients were eligible for analysis. A blinded, central, region-of-interest analysis showed a significantly lower reduction (<i>p</i> = 0.022) in putamen Ki over 2 years with ropinirole (-13.4%; c = 68) compared with levodopa. Statistical parametric mapping localized lesser reductions in ¹⁸F-dopa uptake in the putamen and substantia nigra with ropinirole. The greatest Ki decrease in each group was in the putamen, but the decrease was significantly lower with ropinirole compared with levodopa (<i>p</i> < 0.001). Ropinirole is associated with slower progression of PD than levodopa as assessed by ¹⁸F-dopa PET. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
Described a clinical trial comparing initial treatment of early Parkinson's Disease (PD) with pramipexole vs levodopa. The investigators also explored the effects of these treatment strategies on dopamine transport density, a marker of the dopaminergic neuron terminal, as measured by single photon emission computerized tomography (SPECT) and Β-CIT. 301 patients with early PD aged 30 yrs or older were randomized 1:1 to pramipexole or levodopa, in combination with carbidopa, using a computer-generated randomization plan. Ss entered a 10-wk dosage escalation period followed by a 21-mo maintenance period. It was found that pramipexole treatment results in less development of wearing off, dyskinesias, or on-off motor fluctuations compared with levodopa. The mean improvement in total Unified Parkinson's Disease Rating Scale (UPDRS) score from baseline to 23.5 mo was greater in levodopa Ss than in pramipexole Ss. Somnolence was more common in pramipexole-treated Ss than in levodopa-treated Ss, a difference also seen in the escalation phase of treatment. The mean decline in Β-CIT striatal uptake over the 23.5 mo did not differ between treatment groups. The authors note that both pramipexole and levodopa improve parkinsonian features as measured by the UPDRS, but conclude that pramipexole is not as potent as levodopa for treatment. (PsycInfo Database Record (c) 2021 APA, all rights reserved)
BACKGROUND: There is debate about whether the initial treatment for patients with Parkinson's disease should be levodopa or a dopamine agonist.
METHODS: In this prospective, randomized, double-blind study, we compared the safety and efficacy of the dopamine D2-receptor agonist ropinirole with that of levodopa over a period of five years in 268 patients with early Parkinson's disease. If symptoms were not adequately controlled by the assigned study medication, patients could receive supplementary levodopa, administered in an open-label fashion. The primary outcome measure was the occurrence of dyskinesia.
RESULTS: Eighty-five of the 179 patients in the ropinirole group (47 percent) and 45 of the 89 patients in the levodopa group (51 percent) completed all five years of the study. In the ropinirole group 29 of the 85 patients (34 percent) received no levodopa supplementation. The analysis of the time to dyskinesia showed a significant difference in favor of ropinirole (hazard ratio for remaining free of dyskinesia, 2.82; 95 percent confidence interval, 1.78 to 4.44; P<0.001). At five years, the cumulative incidence of dyskinesia (excluding the three patients who had dyskinesia at base line), regardless of levodopa supplementation, was 20 percent (36 of 177 patients) in the ropinirole group and 45 percent (40 of 88 patients) in the levodopa group. There was no significant difference between the two groups in the mean change in scores for activities of daily living among those who completed the study. Adverse events led to the early withdrawal from the study of 48 of 179 patients in the ropinirole group (27 percent) and 29 of 89 patients in the levodopa group (33 percent). The mean (+/-SD) daily doses given by the end of the study were 16.5+/-6.6 mg of ropinirole (plus 427+/-221 mg of levodopa in patients who received supplementation) and 753+/-398 mg of levodopa (including supplements).
CONCLUSIONS: Early Parkinson's disease can be managed successfully for up to five years with a reduced risk of dyskinesia by initiating treatment with ropinirole alone and supplementing it with levodopa if necessary.
This pilot study was performed to compare the occurrence of long term motor complications in Parkinson's disease when the introduction of levodopa was delayed by an initial treatment with high doses of bromocriptine alone. The trial was a prospective randomised controlled study comparing 31 previously untreated patients with Parkinson's disease initially given bromocriptine alone to which levodopa was later added (group B/D) and 29 other previously untreated patients with Parkinson's disease immediately given levodopa alone (group D). The end point was the occurrence of the first motor complications (wearing off or dyskinesia). Group B/D patients received bromocriptine (52 (SEM 5) mg/day) for 2.7 years, to which levodopa was later added (471 (SEM 46) mg/day). Group D patients received a comparable dose of levodopa alone (569 (SEM 47) mg/day). Both had similar disability scores at the end of the study. Motor complications were fewer and appeared later in group B/D than in group D (56% after 4.9 (SEM 0.5) years of treatment v 90% after 2.7 (SEM 0.5) years, p < 0.01). Wearing off appeared later (p < 0.01) in group B/D (4.5 (SEM 0.6) years) than in group D (2.9 (SEM 0.6) years). Peak dose dyskinesia occurred less often in group B/D patients (three v 14 cases, p < 0.01). This study showed that a three year initial monotherapy with high doses of bromocriptine followed by addition of levodopa delayed the occurrence of long term motor complications usually found in patients with Parkinson's disease treated with levodopa alone from the beginning.
OBJECTIVE: To determine the optimum treatment for early Parkinson's disease.
DESIGN: An open, long term, prospective randomised trial conducted by the Parkinson's Disease Research Group of the United Kingdom.
SETTING: 93 hospitals throughout the United Kingdom.
SUBJECTS: 782 patients with early Parkinson's disease who were not receiving dopaminergic treatment.
INTERVENTIONS: Patients allocated to treatment with levodopa/dopa decarboxylase inhibitor alone (arm 1), levodopa/decarboxylase inhibitor/selegiline in combination (arm 2), or bromocriptine (arm 3).
MAIN OUTCOME MEASURES: Disability assessment as judged by improvement on Hoehn and Yahr, modified Webster, and North Western University disability scales. Adverse event profile and mortality ratios.
RESULTS: Interim results indicate that all three treatment regimens led to improvement in baseline disabilities after 12 months' treatment and that deterioration in control was apparent by three years. No significant differences were found between the results of treatment in arm 1 and arm 2, but both were significantly more effective than bromocriptine (arm 3) and had fewer early adverse reactions. The adjusted difference (95% confidence interval) in Webster rating for arm 3 v 1 was 0.93 points (0.27 to 1.50; p = 0.0058) and for arm 3 v 2 was 1.25 points (0.61 to 1.89; p = 0.0002). The incidence of dyskinesias and motor oscillations, however, was significantly lower in arm 3 (2% and 5%, respectively) than in arm 1 (27% and 33%, respectively) and arm 2 (34% and 35%, respectively).
CONCLUSIONS: As there were no marked differences in functional improvement between the three groups the choice of treatment in the early stages of Parkinson's disease may not be critical.
One hundred and twenty nine de novo patients with idiopathic Parkinson's disease are being followed over a 5 year period in a double-blind multicentre study comparing low-dose bromocriptine (less than 30 mg/day) with low-dose levodopa-carbidopa (less than 600/150 mg/day). Sixty six patients have been randomised to bromocriptine and 63 patients to levodopa-carbidopa. Improvement has been greater in the levodopa-carbidopa group than in the bromocriptine group. Involuntary movements have so far only occurred in patients on levodopa-carbidopa, the incidence being much lower than is usually described with conventional doses. Mild, end-of-dose failure has occurred in both treatment groups; however, no patient has developed the "on-off" phenomenon. Low-dose levodopa-carbidopa appears to be a more effective anti-Parkinsonian treatment than low-dose bromocriptine but more prone to cause dyskinesia.
The long term effects of a de novo treatment with levodopa versus bromocriptine were compared in respectively 13 and 15 previously untreated patients with Parkinson's disease in a prospective randomised trial. Thirteen patients were treated with levodopa alone (mean dose 444, SEM 63 mg daily) whereas 15 others received bromocriptine alone (mean dose 50, SEM 6 mg daily) during 37, SEM 4 and 32, SEM 4 months respectively. For a similar decrease in the Columbia rating scale, the nature of long term side effects was different in the two groups: three patients on levodopa developed peak-dose dyskinesias and one other dystonia. With bromocriptine, one patient developed a severe psychosis whereas 3 others suffered from primary lack of efficacy (1 case) or late decrease in efficacy (2 cases). These results demonstrate the potential of D2 dopamine agonists (like bromocriptine) in the de novo treatment of Parkinson's disease; however, their use is limited by their lack of efficacy and/or the occurrence of neuropsychiatric side effects.
A randomized, prospective trial in 90 de novo parkinsonian patients showed that 4 years' treatment with lisuride resulted in significantly fewer end-of-dose disturbances and peak-dose dyskinesias, but also less improvement in parkinsonian disability, than with levodopa. Early combination of lisuride and a low dose of levodopa, during a 4-year follow-up, resulted in a therapeutic response equal to that achieved with high-dose levodopa alone, but significantly fewer end-of-dose failures and dyskinesias. Thus it seems advisable that treatment should begin in the early phase of the disease with a dopamine agonist such as lisuride combined with a low dose of levodopa.
Dopamine agonists are used as initial treatment in patients with Parkinson's disease (PD) to reduce incidence and severity of motor complications. This paradigm is based on long-term studies, allowing "rescue" therapy with levodopa. The present strict monotherapy study (PELMOPET, the acronym for the pergolide-versus-L-dopa-monotherapy-and-positron-emission-tomography trial) evaluated the efficacy and safety of pergolide versus levodopa without levodopa "rescue" medication. This multicenter, double-blind, randomized, 3-year trial compared pergolide monotherapy (n=148) with levodopa monotherapy (n=146) in dopamine-naive patients with early PD (Hoehn and Yahr stage 1-2.5). Primary efficacy measures were clinical efficacy, severity and time to onset of motor complications, and disease progression. During the 3 years, severity of motor complications was significantly lower and time to onset of dyskinesia was significantly delayed in the group receiving pergolide (3.23 mg/day) compared with those receiving levodopa (504 mg/day). However, time to onset of motor complications was not longer in patients receiving pergolide after 3 years. Symptomatic relief (assessed by Unified Parkinson's Disease Rating Scale [UPDRS], UPDRS II, and III, Clinical Global Impressions [CGI] severity, and CGI and Patient Global Impressions [PGI] improvement) was significantly greater in patients receiving levodopa. Adverse events led to discontinuation of therapy in 17.6% of pergolide patients and 9.6% of levodopa patients. This is the first study comparing strict monotherapy with a dopamine agonist versus levodopa in previously untreated early PD. In principle, both levodopa and a dopamine agonist such as pergolide seem to be suitable options as initial PD therapy. The choice remains with the treating physician based on the different efficacy and adverse event profiles.
