Dual dopamine agonist treatment in Parkinson’s disease

We studied the effectiveness of cabergoline as an adjunct in patients with early Parkinson's disease receiving another dopamine agonist (pramipexole or ropinirole), at the maximal permitted dose. The study enrolled 47 patients: 35 had motor fluctuations and were receiving a dopamine agonist with levodopa; and 12, without motor fluctuations, were receiving a dopamine agonist without levodopa. These medications had in all cases failed to achieve adequate symptom control. In the 35 patients with motor fluctuations, when cabergoline was added to therapy, the time spent in the OFF period decreased by 65.6% (from 3.14+/-1.11 to 1.08+/-1.07 hours p<0.0001); and the Unified Parkinson's Disease Rating Scale (UPDRS) motor score decreased by 19.24% (from 41.68+/-12.6 to 33.66+/-10.22; (p<0.0001) during the OFF condition, and by 7.11% (from 17.01+/-6.63 to 15.8+/-7.22; p<0.001) during the ON condition. Nocturnal akinesia improved in all the patients except one. In the 12 patients without motor fluctuations, when cabergoline was added, the UPDRS score improved by 34.4% (from 23.5+/-5.3 to 15.5+/-4.7).This open study shows that dual dopamine agonist therapy can be useful in the symptomatic treatment of patients with early or more advanced Parkinson's disease receiving therapy with or without levodopa.     

High-dose therapy with ropinirole in patients with Parkinson's disease

Summary. Ropinirole is effective as mono- and combination therapy in PD. Previous studies have used a maximal dose of 24 mg/day; the present study assesses the effect of higher doses (up to 36 mg/day) on patients with motor fluctuations. Outcome measures were changes in the motor function score of the Unified Parkinson's Disease Rating Scale, the duration of dyskinesias and reductions in levodopa dose. 21/22 patients completed the study. The mean daily ropinirole dose at endpoint was 26.2 mg (SD, 4.43 mg, range 20–36 mg). Improvements in motor function (29%) and the duration of dyskinesias (45%) from baseline to endpoint were significant (p < 0.01 and p < 0.05, respectively). The mean levodopa dose fell by 32% during the study (from 599 mg to 409 mg; p = 0.007). Side effects were mild. High-dose ropinirole (20–36 mg/day) was well tolerated and conferred significant clinical benefit on patients with motor fluctuations. Received June 25, 2001; accepted July 9, 2001     

Dyskinesias do not develop after chronic intermittent levodopa therapy in clinically hemiparkinsonian rhesus monkeys

The stable 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced hemiparkinsonian (HP) rhesus monkey model of Parkinson's disease (PD) has been frequently used to test preclinical experimental therapeutics targeted to treat patients with advanced PD who suffer from motor fluctuations and drug-induced dyskinesias. We retrospectively analyzed data from 17 stable HP rhesus monkeys treated long-term with chronic intermittent dosing of levodopa (LD) in an attempt to induce choreoathetoid and dystonic dyskinesias. Rhesus monkeys in stable HP state for greater than 6 months as confirmed by multiple blinded behavioral ratings and (18)F-dopa Positron Emission Tomography (PET) were treated with optimal doses of LD to provide maximal amelioration of unilateral clinical parkinsonism without any adverse effects. Thereafter, each animal was given chronic intermittent daily challenge with doses of LD up to 700 mg/day orally or with 300 mg/kg/day parenteral injections. LD treatments failed to induce choreoathetoid and dystonic dyskinesias in these animals despite chronic intermittent high dose administration. These results suggest that the stable strictly unilateral HP rhesus monkey model of PD may not be a suitable animal model to test experimental therapeutics targeted against dyskinesias, and that bilateral parkinsonian rhesus models that readily demonstrate drug-induced dyskinesias and clinically relevant motor fluctuations are more appropriate for preclinical experimental testing of therapies designed to treat patients with advanced PD.     

A 3-year randomized trial of ropinirole and bromocriptine in early Parkinson's disease. The 053 Study Group.

OBJECTIVE: To compare the long-term efficacy and safety of ropinirole with bromocriptine over 3 years in patients with early PD with limited or no previous dopaminergic therapy. METHODS: In this prospective, double-blind, parallel-group study, 335 patients were randomized to 0.75 mg ropinirole or 1.25 mg bromocriptine titrated upward at weekly intervals--maximum permitted daily doses were 24 mg ropinirole, 40 mg bromocriptine. RESULTS: Approximately one third of patients in each group withdrew prematurely, mostly because of adverse experiences; 61/102 (60%) of ropinirole-treated and 59/112 (53%) of bromocriptine-treated patients completed the study on the dopamine agonist alone. Mean doses for all patients at completion were 12 mg (SD 6) ropinirole and 24 mg (SD 8) bromocriptine. Occurrence of adverse experiences in both groups was similar. Emergence of dyskinesias was low. Both treatments induced marked improvements in Unified Parkinson's Disease Rating Scale activities of daily living (ADL, Part II) and motor (Part III) scores over the first 12 weeks, which were maintained during the study. After 3 years, patients in the ropinirole group had a mean improvement in motor score of 31% compared with 22% in the bromocriptine group (p = 0.086) and a significantly better ADL score (treatment difference 1.46 points, p = 0.009) [corrected]. CONCLUSIONS: Both dopamine agonists are effective in the early treatment of a high proportion of PD patients; effectiveness persists for at least 3 years. Those who completed the study had a significantly better functional status on ropinirole than on bromocriptine.     

Real life evaluation of safinamide effectiveness in Parkinson’s disease

In this retrospective study, we evaluated both efficacy and effectiveness of safinamide 50 and 100 mg in the treatment of motor fluctuations and disabling dyskinesias in a cohort of patients with idiopathic Parkinson’s disease (PD). Ninety-one PD patients were evaluated during the first year of commercialization of the drug, both prior to starting safinamide and at the last available follow-up. Evaluations were based on the Unified Parkinson’s Disease Scale part III (UPDRS III), Hoehn & Yahr (HY), Unified Dyskinesia Rating Scale (UDysRS) walking and balance item 9 score, daily time spent in OFF and in ON with disabling dyskinesias (1 week diary), mean daily dose of levodopa (LD), dopamine-agonists (DA), catechol-O-methyl transferase inhibitor (COMT-I), monoamine oxidase B inhibitor (MAOB-I), and their LD equivalent dose (LEDD). Eight patients withdrew safinamide within the first month for minor side effects. At the follow-up evaluation, after a mean time with safinamide of 7.5 months?±?3.4, all patients showed a significant improvement of all the scale scores, except for HY, and of the daily dosages of the drugs and the LEDD. The same results were shown by PD patients treated with safinamide 50 mg and patients who started safinamide without switching from a previous MAOBI. PD patients with safinamide 100 mg and patients who started safinamide switching from a previous MAOBI significantly improved in time spent in OFF and LEDD. In conclusion, safinamide is safe and effective in improving motor complications in patients with idiopathic PD and can be considered a useful levodopa sparing strategy.     

Ropinirole therapy for Parkinson's disease

Ropinirole (Requip, GlaxoSmithKline) is a novel nonergoline dopamine D2 agonist indicated for the treatment of early and advanced Parkinson's disease. It is mainly metabolized by the liver and its elimination half-life is approximately 5.8 h. When used as monotherapy in early Parkinson's disease, ropinirole improves signs and symptoms of the disorder. When used as an adjunct to levodopa in advanced Parkinson's disease patients with motor fluctuations, ropinirole reduces off time and allows a reduction of levodopa dose. The initial use of ropinirole in early Parkinson's disease to which levodopa is added when necessary, has been demonstrated to lead to a lower incidence of dyskinesias compared with treatment with levodopa alone. An 18F-dihydroxyphenylalanine positron emission tomography study suggested the possibility that ropinirole could slow the progression of loss of dopamine neurons compared with treatment with levodopa but this remains to be proven. Side effects of ropinirole include nausea, somnolence, edema, orthostatic hypotension, hallucinations and dyskinesia. A once-daily formulation of ropinirole is currently in development that has the potential for greater convenience, improved tolerability and greater efficacy.     

Switching from bromocriptine to ropinirole in patients with advanced Parkinson's disease: open label pilot responses to three different dose-ratios.

Newly introduced dopamine agonists, such as ropinirole, may offer advantages compared to such older drugs as bromocriptine in patients with advanced Parkinson's disease (PD) with response oscillations or waning efficacy. Dose equivalence of these two drugs, however, has not been well established, which may complicate switching in clinical practice. In 23 such patients with advanced PD no longer satisfactorily responsive to prolonged bromocriptine therapy (mean dose: 18.9 +/- 6.5 mg/d), we prospectively switched the medication to ropinirole administered at three different dose-ratios (5:1, 3:1, and 2:1), increased at monthly intervals. Selegiline remained unmodified in all 17 patients receiving this medication. A dose-ratio of bromocriptine to ropinirole of close to 2:1 (1.87; mean ropinirole dose: 10.1 +/- 2.5 mg/d) was the only dose that significantly reduced mean motor Unified Parkinson's Disease Rating Scale (UPDRS) scores ( p = 0.030, analysis of variance). Individually considered, however, four patients (21%) scored worse even at this dose-ratio when compared to baseline assessment on bromocriptine. "Off" time was reduced by 57.3% in fluctuating patients, and the dyskinesia score decreased by 53.8%, although the changes were not statistically significant. Higher bromocriptine to ropinirole dose ratios (i.e., 5:1 and 3:1) resulted in "off"-time increases in half of the patients with fluctuations, and two previously stable patients developed a wearing-off effect and one other patient experienced off-time dystonia. One patient developed dose-dependent dopaminomimetic psychotic symptoms with ropinirole. In conclusion, "off"-time motor scores and possibly "off"-time duration, and severity of dyskinesias in patients with advanced PD with prolonged bromocriptine therapy may improve in a majority of cases by switching to ropinirole, provided that the latter drug is administered at a dose ratio of 2:1 compared to bromocriptine. Higher dose ratios are often ineffective or may even cause a clinical worsening of symptoms in some patients.     

Clinical and neuropsychological follow up at 12 months in patients with complicated Parkinson's disease treated with subcutaneous apomorphine infusion or deep brain stimulation of the subthalamic nucleus

BACKGROUND: The clinical condition of advanced Parkinson's disease (PD) patients is often complicated by motor fluctuations and dyskinesias which are difficult to control with available oral medications. OBJECTIVE: To compare clinical and neuropsychological 12 month outcome following subcutaneous apomorphine infusion (APO) and chronic deep brain stimulation of the subthalamic nucleus (STN-DBS) in advanced PD patients. METHODS: Patients with advanced PD and medically untreatable fluctuations underwent either APO (13 patients) or STN-DBS (12 patients). All patients were clinically (UPDRS-III, AIMS, 12 h on-off daily) and neuropsychologically (MMSE, Hamilton-17 depression, NPI) evaluated at baseline and at 12 months. APO was discontinued at night. RESULTS: At 12 months APO treatment (74.78+/-24.42 mg/day) resulted in significant reduction in off time (-51%) and no change in AIMS. Levodopa equivalent medication doses were reduced from 665.98+/-215 mg/day at baseline to 470+/-229 mg/day. MMSE, NPI, and Hamilton depression scores were unchanged. At 12 months STN-DBS resulted in significant clinical improvement in terms of reduction in daily off time (-76%) and AIMS (-81%) as well as levodopa equivalent medication doses (980+/-835 to 374+/-284 mg/day). Four out of 12 patients had stopped oral medications. MMSE was unchanged (from 28.6+/-0.3 to 28.4+/-0.6). Hamilton depression was also unchanged, but NPI showed significant worsening (from 6.58+/-9.8 to 18.16+/-10.2; p<0.02). Category fluency also declined. CONCLUSIONS: Both APO and STN-DBS resulted in significant clinical improvement in complicated PD. STN-DBS resulted in greater reduction in dopaminergic medications and provided 24 h motor benefit. However, STN-DBS, unlike APO, appears to be associated with significant worsening on NPI resulting from long term behavioral problems in some patients.     

Pardoprunox as adjunct therapy to levodopa in patients with Parkinson's disease experiencing motor fluctuations: results of a double-blind, randomized, placebo-controlled, trial

AimsTo determine the efficacy and safety of pardoprunox in levodopa-treated patients with Parkinson’s disease (PD) experiencing motor fluctuations.MethodsPatients were randomized to pardoprunox (up to 42 mg/day, n = 150) or placebo (n = 144). Pardoprunox was titrated to an optimal dose over 7 weeks, followed by a 12-week stable dose period. The primary efficacy variable was the change from baseline to study endpoint in total daily OFF time, based on patient diaries. Secondary analyses included the change in ON time without troublesome dyskinesias, UPDRS-ADL + Motor ON, UPDRS-ADL OFF and PDQ-39. Subgroup analyses explored the impact of pardoprunox on dyskinesias (UPDRS items 32 + 33), depression (Hospital Anxiety Depression Scale) and pain (Visual Analogue Scale).ResultsPardoprunox significantly reduced OFF time versus placebo (?1.62 h/day versus ?0.92 h/day, respectively, p = 0.0215). Compared to placebo, pardoprunox improved ON time without troublesome dyskinesias (p = 0.0386), UPDRS-ADL + Motor ON (p = 0.0003), and UPDRS-ADL OFF (p < 0.0001), while no significant difference was observed on PDQ-39. A high drop-out rate due to adverse events (AEs) (pardoprunox, 37%; placebo, 12%) suggested that the selected dose range may have been too high, and/or titration was too rapid.ConclusionsPardoprunox decreased OFF time and increased ON time without troublesome dyskinesias in levodopa-treated PD patients. The high drop-out rate at the selected doses justifies the investigation of lower doses. The impact of pardoprunox on dyskinesias and non-motor symptoms deserves further investigation.     

Entacapone in elderly Parkinsonian patients experiencing levodopa-related wearing-off: a pilot study

Levodopa (LD) provides the most effective symptomatic treatment for Parkinson's disease (PD). Long-term treatment with LD, however, is often associated with the development of response fluctuations. Previous evidence suggests that the short half-life of LD is a major contributor to the development of response fluctuations and the wearing-off phenomenon in particular. Entacapone, a peripheral catechol-O-methyltransferase inhibitor has been shown to reduce OFF time and increase ON time in several therapeutic trials on PD patients treated with LD experiencing motor fluctuations. However, data are missing on the tolerability and efficacy of entacapone in elderly PD patients. This is of particular relevance, as most PD patients develop LD-related motor fluctuations after several years of disease duration. Here we report that addition of entacapone in a group of 45 elderly PD patients with LD-related motor fluctuations is well tolerated and efficacious in reducing the time, frequency and severity of the OFF periods. These data suggest that the drug can be used safely and efficaciously in elderly PD patients.     

Apomorphine infusion and the long-duration response to levodopa in advanced Parkinson's disease

The authors investigated the long-duration response to levodopa in advanced Parkinson's disease. Eight patients with advanced Parkinson's disease disabled by severe ON/OFF fluctuations treated by chronic daytime subcutaneous apomorphine infusion with supplemental oral levodopa were studied. On day 1, oral levodopa was withdrawn at 4:00 pm and on the following morning subcutaneous apomorphine infusion was continued at the same rate without levodopa therapy. While receiving apomorphine alone, seven of the eight patients turned ON, and their usual dyskinesias returned. The ON phase persisted for 60 to 100 minutes (mean, 185.7 minutes) but then, despite continued, constant-rate apomorphine infusion to stabilize plasma levels, switched to an OFF phase. The authors conclude that the clinical effect of apomorphine is sustained by levodopa long-duration response. This effect is probably the result of postsynaptic mechanisms. In patients with advanced Parkinson's disease, the long-duration response to levodopa is present although slightly diminished.     

Amantadine sulfate infusion effect on N30 somatosensory evoked potentials in Parkinson's disease

The purpose of this study was to evaluate the effect of amantadine sulfate infusion on the N30 component of the median nerve short-latency somatosensory evoked potentials (SSEPs) in patients with Parkinson's disease (PD). Twenty patients with advanced PD and severe motor fluctuations received a 6-day course of amantadine sulfate infusion (400 mg/day) plus their usual levodopa medication. Patients were assessed clinically by means of the Unified Parkinson's Disease Rating Scale (UPDRS-III and -IV). SSEPs to median nerve stimulation were recorded from the parietal and frontal regions before and after the 6-day course of amantadine infusion. Mean UPDRS motor score during the ON and OFF phase improved after amantadine infusion, as did motor fluctuations. SSEP changes resulting from amantadine sulfate treatment were observed in the P20-N30 amplitude as follows: Mean P20-N30 amplitudes before and after treatment were 2.15 +/- 1.11 microV and 3.06 +/- 1.19 microV respectively (p = 0.000), whereas mean N30-P40 amplitude increased from 2.7 +/- 1.6 microV to 3.9 +/- 1.3 microV after treatment (p = 0.000). Our results indicate that coincident to its clinical impact, amantadine infusion in patients with PD affects electrophysiologic parameters as well.     

A six-month multicentre, double-blind, bromocriptine-controlled study of the safety and efficacy of ropinirole in the treatment of patients with Parkinson's disease not optimally controlled by L-dopa

OBJECTIVES: To compare the safety and efficacy of ropinirole and bromocriptine as adjunct therapy in patients with Parkinson's disease (PD) not optimally controlled by L-dopa. METHODS: A randomised, double-blind trial in which 555 patients were assigned to three treatment groups according to the level of daily dosage of L-dopa, presence of motor fluctuations, and use of dopamine agonist before study entry. Patient response was defined as at least a 20% reduction in daily L-dopa dose plus: for patients with no prior treatment and no motor fluctuations, a 20% reduction in UPDRS motor score; for patients with motor fluctuations, a 20% reduction in time spent "off"; and for patients already taking an agonist, an improvement on the CGI scale. RESULTS: Safety assessments showed no significant differences in the two treatment groups for patients without prior dopamine-agonist therapy. In the group of patients with prior dopamine-agonist therapy, more patients reported adverse events in the ropinirole group (90% versus 79%, p < 0.001). The proportions of responders tended to be higher in ropinirole groups compared with bromocriptine groups and, in the subgroup with motor fluctuations, this difference was statistically significant (9.1% versus 0.0%, respectively; p < 0.05). CONCLUSIONS: Both drugs were well tolerated. In patients receiving a relatively high dose of L-dopa and requiring the addition of a dopamine agonist to control motor fluctuations or dyskinesias, ropinirole was significantly more effective than bromocriptine.     

A six-month multicentre,double-blind,bromocriptine-controlled study of the safety and efficacy of ropinirole in the treatment of patients with Parkinson's disease not optimally controlled by <Emphasis Type="SmallCaps">l</Emphasis>-dopa

Summary. Objectives: To compare the safety and efficacy of ropinirole and bromocriptine as adjunct therapy in patients with Parkinson's disease (PD) not optimally controlled by L-dopa. Methods: A randomised, double-blind trial in which 555 patients were assigned to three treatment groups according to the level of daily dosage of L-dopa, presence of motor fluctuations, and use of dopamine agonist before study entry. Patient response was defined as at least a 20% reduction in daily L-dopa dose plus: for patients with no prior treatment and no motor fluctuations, a 20% reduction in UPDRS motor score; for patients with motor fluctuations, a 20% reduction in time spent "off"; and for patients already taking an agonist, an improvement on the CGI scale. Results: Safety assessments showed no significant differences in the two treatment groups for patients without prior dopamine-agonist therapy. In the group of patients with prior dopamine-agonist therapy, more patients reported adverse events in the ropinirole group (90% versus 79%, p < 0.001). The proportions of responders tended to be higher in ropinirole groups compared with bromocriptine groups and, in the subgroup with motor fluc-tuations, this difference was statistically significant (9.1% versus 0.0%, respectively; p < 0.05). Conclusions: Both drugs were well tolerated. In patients receiving a relatively high dose of L-dopa and requiring the addition of a dopamine agonist to control motor fluctuations or dyskinesias, ropinirole was significantly more effective than bromocriptine. Received January 31, 2001; accepted October 23, 2001     

Pergolide in the treatment of patients with early and advanced Parkinson's disease

Introduced on the market in 1989, pergolide, a D1/D2 dopamine receptor agonist, is still widely prescribed for the treatment of patients with early and advanced Parkinson's disease (PD). Initially, pergolide was introduced as an adjunct therapy to levodopa treatment in patients exhibiting fluctuating motor responses and dyskinesias. Results of recent randomized controlled clinical trials in de novo patients with PD show that pergolide is able to improve parkinsonian symptoms when used as monotherapy. Moreover, preliminary results of a long-term monotherapy study in early PD suggest that pergolide is as effective as levodopa, and that a significant delay in the time of the onset of levodopa-induced motor complications can be obtained. A number of randomized studies have shown that pergolide is more effective than bromocriptine as adjunct therapy to levodopa in patients with advanced PD; the greater benefit found with pergolide could be ascribed to its action on both D1 and D2 dopamine receptors. However, controlled comparative studies with new dopamine agonists, such as ropinirole, cabergoline, and pramipexole, have not been performed yet. Interestingly, few open studies in patients with complicated PD have shown that high doses of pergolide (> 6 mg/d) are able to improve motor fluctuations and dyskinesias through a dramatic reduction of levodopa dosage. The side-effect profile of pergolide is similar to that of other dopamine agonists, and complications such as sleep attack and serosal fibrosis have been rarely reported.     

Levodopa-induced ocular dyskinesia in Parkinson's disease

Levodopa (LD)-induced dyskinesia (LID), one of the most common motor complications in advanced Parkinson's disease (PD), involve mostly the limbs, trunk and head, but unusual locations have been reported including respiratory muscles, the face and the eyes. The aim of this study was to further investigate the frequency and characteristics of LD-related abnormal involuntary eye movements (AIEMs) in PD. Thirty-two patients with advanced PD and various motor complications were evaluated and videotaped in an ON and OFF state. We found AIEMs in five patients (16%) which were present exclusively during the ON state and which completely disappeared when OFF. They consisted of repeated, stereotyped upward and/or sideways gaze deviation movements, sometimes phasic, brief and jerky, sometimes tonic and sustained for several seconds. The main direction of gaze deviation was toward the side more affected by parkinsonism. AIEMs typically paralleled limb and trunk LID and were modulated by the same facilitation and inhibitory maneuvers. We concluded that AIEMs are not uncommon in advanced PD and represent a particular topography of LID, hence the term 'ocular dyskinesia' to designate these AIEMs that seem to have a specific pattern in PD as compared with other forms of parkinsonism.     

L-deprenyl (selegiline) added to Sinemet CR in the management of Parkinson's disease patients with motor response fluctuations

L-deprenyl (Eldepryl) added to Sinemet CR in the treatment regimens of seven patients with Parkinson's disease (PD) and therapeutic response fluctuations (RF) allowed a statistically significant reduction in total daily levodopa intake and an increase in the mean interdose interval. Trends were noted towards a reduction in the number of daily "off" periods and an increase in the portion of the waking day spent "on." Three patients suffered an increase in the intensity of their dyskinesias, and discontinued taking deprenyl. Four patients, all of whom reported improved functioning during "off" periods, have continued taking the combination. Sinemet CR and deprenyl can safely be used together in patients with advanced PD, and the combination may result in improved control of motor fluctuations in selected patients.     

High-dose treatment with pergolide in Parkinson's disease patients with motor fluctuations and dyskinesias

Motor complications arising after long-term treatment with levodopa remain one of the main challenges in the treatment of patients with Parkinson's disease (PD). Monotherapy with dopamine agonists may delay the onset of motor complications or reduce their severity when added to levodopa treatment. Here, we retrospectively analyzed data from 62 patients with advanced PD who presented with moderate to severe response fluctuations in whom we increased the dose of oral treatment with pergolide beyond 4.5mg daily. Patients had been treated with levodopa for 10.7+/-4.8 years. Pergolide was increased to 8.2+/-4.3 mg per day over a median titration period of 13.5 weeks. Mean daily dose of levodopa prior to pergolide high-dose treatment was 733+/-468 mg and decreased to 348+/-186 mg after pergolide titration. The duration of OFF times decreased from 7.3+/-3.8 to 1.7+/-0.9 h per day (p < 0.001) measured by patients' diaries. Dyskinesias, present for 5.0+/-3.3 h per day at baseline, were reduced to 1.4+/-0.8 h per day (p < 0.001) and the total daily duration of motor fluctuations (off-time duration plus dyskinesia duration) decreased from 10.5+/-7.0 to 2.8+/-2.2 h (p < 0.001). There was a significant improvement in parkinsonian symptoms (baseline to endpoint reduction of UPDRS III from a median of 36 to 8; p < 0.001). To reduce gastrointestinal side effects 23 patients required concomitant treatment with domperidone. Seven patients developed hallucinations during the titration period, six patients required treatment with clozapine. Our data indicate that increasing the dose of pergolide above 5mg per day can dramatically reduce the need for levodopa, motor fluctuations and severity of clinical symptoms. Controlled trials are needed to further substantiate the efficacy and safety of this treatment strategy.     

Antiparkinsonian activity and dyskinesia risk of ropinirole and L-DOPA combination therapy in drug na?ve MPTP-lesioned common marmosets (Callithrix jacchus).

De novo administration of long-acting dopamine agonists, such as ropinirole, to patients with Parkinson's disease or to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated subhuman primates produces a lower incidence of dyskinesia than occurs with L-DOPA. This study compares the intensity of dyskinesia produced by combinations of L-DOPA and ropinirole and by these drugs alone, using the MPTP-treated common marmoset model of Parkinson's disease. The objective is to determine the optimum therapeutic strategy for the long-term control of Parkinson's disease with a minimal risk of dyskinesia. MPTP-treated marmosets received either L-DOPA alone, ropinirole alone, or one of two combinations of these drugs (either L-DOPA dominant or ropinirole dominant) daily for 28 days in doses titrated to produce a similar improvement in disability and increase in locomotion. In the group receiving L-DOPA alone, there was a trend for peak dose locomotor activity to increase and the duration of drug effect to decline over the period of the study. L-DOPA alone induced marked dyskinesia over the period of treatment, in contrast to ropinirole which produced a low intensity of involuntary movements. The L-DOPA dominant combination initially produced little dyskinesia, but this became increasingly intense as the study progressed. In contrast, the ropinirole dominant combination produced no greater intensity of dyskinesia than was produced by ropinirole alone. These data suggest that in early Parkinson's disease, the use of ropinirole alone or in combination with a low-dose L-DOPA might delay the induction of dyskinesias while improving motor performance.     

Patient diaries as a clinical endpoint in Parkinson's disease clinical trials

Parkinson's disease (PD) is the second most common neurodegenerative disorder with an estimated 4 million patients worldwide. L-dopa is standard, and often initial, therapy for patients with this condition; however, with continued dopaminergic treatment and as the disease progresses, the majority of patients experience complications such as "wearing-off" symptoms, dyskinesias, and other motor complications. These complications may become disabling and profoundly affect quality of life. Treatment modification and combination therapies with L-dopa, dopamine agonists, monoamine oxidase type B inhibitors, and catechol-O-methyltransferase inhibitors are commonly used to manage complications. In recent years regulatory agencies, clinical researchers, and sponsors have widely accepted and utilized changes in "ON" and "OFF" time measured by Patient Hauser Diaries as endpoints for measuring efficacy of therapeutics seeking approval for symptomatic treatment of PD. Successful antiparkinsonian medications have been associated with treatment effects of more than 1 h in either reduction of "OFF" time of increase in "ON" time. Accurate "ON" and "OFF" time registration during clinical studies requires rigorous patient training. Reduced compliance, recall bias and diary fatigue are common problems seen with patient diary reported measures. Electronic diaries may help reducing some of these problems but may be associated with other challenges in large, multicenter studies.