Subcutaneous administration of apomorphine in motor fluctuations in Parkinson's disease

Apomorphine, a dopaminergic agonist was given over a period of 12 months to 14 parkinsonian patients suffering from severe L-dopa induced on-off effects. Nine patients (mean age: 52 years; mean age at onset of the disease: 37 years), were treated by continuous infusion with a portable minipump, and 5 others by multiple injections with a penject. The mean duration of daily off periods was reduced by two thirds in all patients. The motor fluctuation intensity was only diminished in the 9 patients treated by continuous infusion. These patients received a mean apomorphine daily dose of 93 mg and L-dopa dosage was reduced by 53 p. 100. Red fibrous subcutaneous nodules occurred at the injection sites in all patients treated by infusion. This study confirms the effectiveness of subcutaneous apomorphine administration in the treatment of severe motor fluctuations.     

Apomorphine in treatment of Parkinson's disease with fluctuations

Apomorphine is a non-specific dopamine agonist, most similar to it, with a strong action on D2, D3, D4 receptors and weaker action on D1 and D5 receptors. It has been known since 100 years, and in Parkinson's disease it was used first in 1970 by Schwab and Cotzias. Apomorphine is used in Parkinson's disease with high-grade fluctuations of symptoms which cannot be controlled by oral drugs, especially in off" periods resistant to levodopa. After subcutaneous administration it changes the "off" to "on" period within 5-10 minutes. Unfortunately, its effect is short-lasting and wears off after 40-90 minutes. Apomorphine is administered in repeated single subcutaneous injections or in continuous subcutaneous infusion, if more than 7-9 single injections are required daily. Before beginning of treatment the optimal dose of apomorphine should be determined. For counteracting its emetic action domperidon (Motilium) is given additionally 20 mg t.d.s. Apomorphine produces no tolerance and is not losing its effectiveness with continued treatment. The most frequent adverse effects during long-term treatment are local cutaneous reactions, increased intensity of dyskinesia during the "on" period, visual hallucinations whose illusory character is clear to the patient, psychoses, orthostatic hypotension. The authors treated 8 patients with marked fluctuations in Parkinson's disease treated with levodopa. In 7 cases the effects was good--6 of them received 2-3 mg s.c. 3-4 times in 24 hours for 7-12 days. One patient has been treated 9 months with good result. In one case the intensity of dyskinesia made impossible treatment continuation.     

Pen injected apomorphine against off phenomena in late Parkinson''s disease: a double blind, placebo controlled study.

The effect, therapeutic dose range, and pharmacokinetics of apomorphine, given as subcutaneous injections by a single use pen, were evaluated in the treatment of off phenomena in 22 patients with idiopathic Parkinson's disease. At study entry a placebo controlled apomorphine test was performed, and apomorphine doses were then individually titrated (mean 3.4 (range 0.8-6.0) mg) and compared with placebo in a double blind cross over phase. With apomorphine compared with placebo the mean daily duration of off periods was reduced by 51% as assessed by the patients and by 58% as assessed by the staff. The severity of off periods was also significantly reduced. The effect was unchanged after a maintenance phase of eight weeks. At study termination 13 of 14 patients were able to inject themselves and 11 of 14 patients found that their feeling of freedom had increased. The most common adverse events were nausea, subcutaneous nodules, and increased frequency of involuntary movements. Pharmacokinetics were linear and did not change with repeat dosing. The tmax ranged from five to 45 minutes (16 patients). It is concluded that pen injected apomorphine is a valuable treatment for patients with advanced Parkinson's disease with on-off phenomena.     

Continuous subcutaneous apomorphine therapy improves dyskinesias in Parkinson's disease: a prospective study using single-dose challenges.

Continuous subcutaneous (SC) infusion of the dopamine agonist apomorphine was shown in retrospective studies to improve drug-induced dyskinesias in Parkinson's disease (PD). We prospectively assessed the antidyskinetic effect of continuous SC apomorphine therapy using subjective and objective measures, and sought to determine whether any observed dyskinesia reduction could be corroborated using single-dose dopaminergic challenges. Twelve PD patients with on-off fluctuations and disabling dyskinesias who were scheduled to start apomorphine pump treatment underwent acute levodopa and apomorphine challenges at baseline and 6 months later. Video recordings involving motor tasks were rated blindly by two independent raters using modified AIMS and Goetz dyskinesia scales. At 6 months, mean apomorphine dose was 75.2 mg per day and the mean L-dopa dose had been reduced by 55%. Daily off time in patients' diaries was reduced by 38% (2.4 hours). The L-dopa challenges showed a reduction of 44% in AIMS and 40% in Goetz scores (both P < 0.01). Apomorphine challenges showed a reduction of 39% in AIMS and 36% in Goetz scores (both P < 0.01). Patients' self-assessment scores reflected these significant changes. Dyskinesia improvement correlated with reduction in oral medication and with the final apomorphine dose (P < 0.05). This prospective study confirms marked dyskinesia reduction on continuous subcutaneous apomorphine therapy, paralleled by reduced dyskinesias during dopaminergic challenge tests. Our findings support the concept that replacement of short-acting oral antiparkinsonian medication with continuous dopamine receptor stimulation may reverse, at least partially, the sensitization process believed to mediate the development of drug-induced dyskinesias in PD.     

Subcutaneous apomorphine in the treatment of Parkinson''s disease.

Apomorphine a dopamine receptor agonist was given subcutaneously to 57 levodopa treated parkinsonian patients with refractory off-period disabilities for a median period of 16 months. In 30 given intermittent suprathreshold injections the mean number of hours spent in a disabling off state fell from 6.9 to 2.9. Similar benefit was observed in 21 patients receiving continuous infusions with additional boluses on demand by mini-pump (mean reduction of hours off from 9.9 to 4.5). Twelve patients have been treated for over two years without tachyphylaxis or loss of response. The incidence of neuropsychiatric side-effects has been low (7%). Six patients failed to show a sustained worthwhile response; severe disabilities during "on" periods being the major problem. Subcutaneous apomorphine is proposed as an effective treatment for patients with incapacitating "off" period disabilities refractory to oral medication and should be considered before experimental implantation procedures.     

Sublingual apomorphine in Parkinson's disease: a clinical and pharmacokinetic study.

The clinical response and the pharmacokinetic parameters of 3 mg subcutaneous (SC) and 30 mg sublingual (SL) apomorphine were compared in nine patients with Parkinson's disease. The magnitude of the motor responses (evaluated by tapping and walking tests and the Webster scale) was similar for SC and SL apomorphine. However, the onset to action was delayed after SL when compared with SC apomorphine. No significant difference was found in bioavailability (area under the curve: AUC) or peak plasma concentration (Cmax) between SC and SL apomorphine, whereas time to peak plasma concentration (Tmax) was shorter after SC apomorphine. Eight other patients were treated for a mean time of 4 months with SL apomorphine with a significant reduction in daily "off" hours. However, four of these eight patients developed stomatitis after some weeks of treatment. These results indicated that (a) pharmacokinetics parallel the clinical response to SL apomorphine, (b) SL apomorphine can reduce severe off periods in parkinsonian patients when used chronically, and (c) its long-term use is limited by a severe side effect (stomatitis).     

A randomized, double-blind, placebo-controlled trial of subcutaneously injected apomorphine for parkinsonian off-state events

OBJECTIVE: To assess the safety and efficacy of subcutaneous apomorphine hydrochloride administration for off-state (poor motor function) periods in patients with Parkinson disease with motor fluctuations under both inpatient titration and outpatient therapeutic conditions. PATIENTS AND METHODS: Twenty-nine patients had advanced Parkinson disease with 2 hours or more off time despite aggressive oral therapy. Patients randomly received titrated doses of subcutaneous apomorphine hydrochloride (2-10 mg, n = 20) or pH-matched vehicle placebo (n = 9) during an inpatient and 1-month outpatient phase. A change in the United Parkinson Disease Rating Scale motor score 20 minutes after inpatient dosing during a practically defined off-state event and the percentage of injections successfully aborting off-state events were the primary inpatient and outpatient efficacy factors. RESULTS: The average (SEM) levodopa equivalent dose of apomorphine hydrochloride was 5.4 +/- 0.5 mg and the mean placebo dose was 1.0 mL. Mean inpatient United Parkinson Disease Rating Scale motor scores were reduced by 23.9 and 0.1 points (62% and 1%) by apomorphine treatment and placebo, respectively (P<.001). The mean percentage of outpatient injections resulting in successful abortion of off-state events was 95% for apomorphine and 23% for placebo (P<.001). Inpatient response was significantly correlated with and predictive of outpatient efficacy (P<.001). The levodopa dose was not predictive of the apomorphine dose requirement. Frequent adverse events included dyskinesia, yawning, and injection site reactions. CONCLUSION: Apomorphine by intermittent subcutaneous injection is effective and safe for outpatient use to reverse off-state events that occur despite optimized oral therapy.     

High-dose ropinirole in advanced Parkinson's disease with severe dyskinesias

Levodopa (LD) is the gold standard of therapy for Parkinson's disease, but it is commonly associated with motor fluctuations and dyskinesias. Dopamine agonists are often used as adjuncts to LD in an attempt to reduce these complications. In this open-label study the authors investigated the effects of high doses of adjunctive ropinirole in 36 patients with advanced Parkinson's disease and normal cognitive status. The daily dose of ropinirole was increased from 18.4 +/- 3.5 mg to 34.7 +/- 5.5 mg, generally in four separate doses. The daily LD dose was decreased from 734.1 +/- 254.8 mg to 502.8 +/- 228.4 mg. After 12 months 25 patients were still on high doses of ropinirole whereas 11 patients had, after either the emergence of side effects or a worsening of their clinical conditions, decreased or interrupted ropinirole. At 12 months, the daily doses of LD and ropinirole were 489 +/- 243 mg and 34.6 +/- 4.6 mg respectively. There was a significant reduction in the Dyskinesia Rating Scale scores during both ON and OFF periods, indicating a reduction in dyskinesias during ON periods and a reduction in dystonias during OFF periods (p < 0.001). Both the intensity and the hours spent during OFF periods were reduced significantly (p < 0.001). Even though these results need to be confirmed through extended controlled studies, the high-dose dopamine agonist strategy is safe for patients with advanced PD in whom a marked motor response to LD (even at very low doses) is associated with severe dyskinesias, and may be used as a means of delaying surgery or as an alternative to continuous apomorphine infusion.     

Nocturnal subcutaneous apomorphine infusion in Parkinson's disease and restless legs syndrome

OBJECTIVES: Nocturnal disabilities leading to fragmented sleep arising from parkinsonian off period related complications are common, under-reported and are difficult to treat. In this study, we evaluate the use of nocturnal continuous subcutaneous overnight apomorphine infusion in Parkinson's disease and restless legs syndrome. METHODS: Six parkinsonian patients and 2 patients with restless legs syndrome with nocturnal disabilities refractory to conventional oral therapy were assessed using a sleep diary while on standard treatment and during nocturnal apomorphine infusion. Three patients agreed to assessments during placebo infusion with normal saline. RESULTS: Apomorphine led to a dramatic reduction of nocturnal awakenings, nocturnal off periods, pain, dystonia and nocturia in parkinsonian patients. In patients with restless legs syndrome, apomorphine reduced nocturnal discomfort, reduced leg movements and improved pain and spasm scores significantly. Placebo infusion reproduced pain, nocturnal spasms and sleep disruption. CONCLUSION: This study suggests that overnight apomorphine infusion may be effective in overcoming refractory nocturnal disabilities in selected patients with Parkinson's disease and restless legs syndrome.     

Deep brain stimulation of the subthalamic nucleus: effectiveness in advanced Parkinson's disease patients previously reliant on apomorphine

OBJECTIVES: To assess the efficacy of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with advanced Parkinson's disease previously reliant on apomorphine as their main antiparkinsonian medication. METHODS: Seven patients with motor fluctuations despite optimal medical treatment given as predominantly apomorphine infusion (n=6), or intermittent apomorphine injections (n=1) underwent bilateral STN DBS using frameless stereotactic surgery. Standard assessments of parkinsonism and motor fluctuations, using Unified Parkinson's Disease Rating Scale (UPDRS) were performed before and six months after surgery. Assessments were performed both on and off medication, and postoperative with the stimulators switched on and off. RESULTS: Bilateral STN DBS improved motor scores (UPDRS III) by 61% when off medication (p<0.05). Clinical fluctuations (UPDRS IV items 36-39) were reduced by 46.2% (p<0.05). Total daily apomorphine dose was reduced by 68.9% (p<0.05) and apomorphine infusion via a pump was no longer required in four patients. There were no operative complications. Two patients required treatment for hallucinations postoperatively but there was no significant change in mini-mental state examination. CONCLUSIONS: In patients with advanced Parkinson's disease, previously reliant on apomorphine, bilateral STN DBS is an effective treatment to reduce motor fluctuations and enable a reduction in apomorphine use.     

Variation in the dopaminergic response during the day in Parkinson disease

OBJECTIVE: In many parkinsonian patients with fluctuating disease the early morning levodopa dose is more effective than the following dose on the same day. In this study we investigated whether the poor responsiveness to the early afternoon dose of levodopa depends only on peripheral and central levodopa pharmacokinetics or also on pharmacodynamic factors. METHODS: Ten parkinsonian patients experiencing postprandial drug-resistant off periods received two boluses of apomorphine by subcutaneous injection at 8 am and 3 pm on two nonconsecutive days. On day 2, therapy was stopped at 11 am. For each bolus we determined time to on, duration of the on state, magnitude of benefit, and levodopa and apomorphine plasma levels at baseline and immediately after patients reached the on state. RESULTS: The mean duration of on phases was significantly shorter and the apomorphine plasma level needed to reach the on state was significantly higher in the afternoon than in the morning (P<0.01 by paired t test). CONCLUSIONS: This study suggest that there is a change in responsiveness to dopaminergic stimulation during the day. The less effective dopaminergic response in afternoon depends on pharmacodynamic factors and not only on peripheral and central levodopa pharmacokinetic.     

Continuous subcutaneous waking day apomorphine in the long term treatment of levodopa induced interdose dyskinesias in Parkinson's disease

OBJECTIVES—To determine whether continous wakingday dopaminergic stimulation with the dopamine agonist apomorphine canreduce levodopa induced dyskinesias in Parkinson's disease
METHODS—19 patients with severe unpredictablerefractory motor fluctuations and functionally disabling levodopainduced dyskinesias were treated with continuous subcutaneoiusapomorphine monotherapy for a minimum duration of 2.7 years
RESULTS—A mean 65% reduction in dyskineticseverity and a mean 85% reduction in frequency and duration occurred.On discontinuing levodopa a concomitant reduction in off period timewas also seen (35% of waking day "off" reduced to 10%)
CONCLUSION—Continuous waking day dopaminergicstimulation with apomorphine reset the threshold for dyskinesias andled to a pronounced reduction in their frequency.Apomorphine should be considered as a less invasive alternative topallidotomy or deep cerebral stimulation in controlling levodopainduced interdose dose dyskinesias.

     

Differences in the motor response to apomorphine between untreated and fluctuating patients with Parkinson's disease.

Behavioral hyposensitivity to repeated apomorphine administration has been observed in fluctuating parkinsonian patients. To investigate whether a similar phenomenon occurs in patients never treated with levodopa, we studied the response to apomorphine in 20 de novo patients with Parkinson's disease. Six patients showed no or minimal improvement after apomorphine injections (maximal dose 3.5 mg). Fourteen patients responded and were then given up to four repeated subcutaneous injections of apomorphine [minimal effective dose (MED)]. The responses of de novo patients were compared with responses in 10 patients with motor fluctuations previously studied by the same protocol. There was no significant difference in latency and duration of motor responses after repeated apomorphine injections in de novo patients. MED was similar in de novo and fluctuating patients, but duration of improvement induced by each apomorphine bolus was longer in the de novo group. These results indicate that response duration to apomorphine is longer in previously untreated patients and that behavioral tolerance associated with pulsatile dopaminergic stimulation by apomorphine occurs mainly in patients with more advanced disease under chronic levodopa therapy.     

Apomorphine monotherapy in the treatment of refractory motor complications of Parkinson's disease: long-term follow-up study of 64 patients.

Continuous subcutaneous infusion of apomorphine is now increasingly recognized as an effective treatment for refractory off periods and peak-dose dyskinesias in Parkinson's disease. We have reviewed our experience with apomorphine infusions, after a strategy decision in 1995 based on emerging preclinical data, to treat all patients with steady-state plasma levels of apomorphine throughout the waking day, minimizing additional pulsatile stimulation either by oral dopaminergic medication or bolus parenteral injections of apomorphine. Sixty-four patients have been treated with apomorphine pumps and 45 of these successfully converted to monotherapy, managing to discontinue all other forms of dopaminergic stimulation during the daytime treatment period with apomorphine. Patients were followed up for a mean of 33.8 months (range, 4-108 months) and clinical data analyzed retrospectively. The mean maintenance dose of apomorphine was 98 mg per 24 hours (monotherapy group: 103 mg/24 hours; polytherapy group: 93 mg/24 hours), which did not significantly increase at final follow-up. There was a mean maximum dyskinesia reduction of 64% (S.D. = 20) in the monotherapy group, compared to 30% (S.D. = 33) in those continuing on polytherapy (P < 0.001), despite a maintained increase in on time (monotherapy group: 55%, P < 0.005; polytherapy group: 50%, P = 0.05). Fifteen patients failed to successfully convert to monotherapy but benefited nonetheless, and only 3 failed apomorphine infusional therapy altogether. Reasons for failure were mixed, including difficulty with compliance and adverse effects such as daytime somnolence, skin complications, and painful dystonias. There was a significantly higher success rate in patients able to manage the treatment either independently or with the help of their caregiver. These results confirm that subcutaneous apomorphine monotherapy can reset peak-dose dyskinesia threshold in levodopa-treated patients and further reduce off-period disability after all available forms of oral medication, including long-acting dopamine agonists, have been tried.     

Apomorfina w zaawansowanej chorobie Parkinsona

Apomorphine is the most potent dopamine receptor agonist and its symptomatic effectiveness is comparable to levodopa. Subcutaneous apomorphine is rapidly and completely absorbed. Plasma peak concentrations are achieved after 5–15 minutes and onset of clinical effect is within 20 minutes. Apomorphine intermittent subcutaneous injections are effective as rescue therapy for unpredictable off periods in advanced Parkinson disease (PD). More often apomorphine is administered as a subcutaneous infusion which secures the continuous dopaminergic stimulation. The benefit on ‘off’ periods is consistent across all studies, but dyskinesia improvement is not so obvious. Two infusion therapies (apomorphine and intraduodenal levodopa) and deep brain stimulation (DBS) are effective in advanced PD patients with untreatable motor complications. Apomorphine infusions should be considered in patients unable to undergo DBS because of cognitive impairment and neurosurgical contraindications.     

Effects of central dopaminergic stimulation by apomorphine on speech in Parkinson's disease

OBJECTIVE: To determine the effect of central dopaminergic stimulation with apomorphine on speech in PD. BACKGROUND: Most patients with PD have a speech disorder. Of those, 89% have involvement of laryngeal function, and 45% have additional articulatory dysfunction. The effect of dopaminergic medications on these two dimensions of speech impairment in PD has not been selectively studied. METHODS: In a randomized, double-blind, placebo-controlled crossover design, patients with PD and speech impairment, Hoehn and Yahr stages 2 to 4 "off," and without severe dyskinesias were given placebo or apomorphine injections 0.05 mg/kg subcutaneously during two consecutive outpatient visits. They were pretreated with domperidone for 48 hours and were tested off their parkinsonian medications for 12 hours. Laryngeal function was assessed by maximum sustained vowel phonations and comfortable vowel phonations. Articulatory function was evaluated by speech intelligibility score, speaking rate, and efficiency ratio. RESULTS: Ten patients, mean age 73.4 years (SD = 6.6), disease duration 8.7 years (SD = 6.3), were tested. The baseline motor score on the Unified Parkinson's Disease Rating Scale (UPDRSm) and all experimental speech variables were equivalent on both placebo and apomorphine days. At a dose of apomorphine that provoked improvement in UPDRSm (p = 0.0078), no index of either laryngeal or articulatory function improved significantly after apomorphine administration. CONCLUSION: Laryngeal and articulatory speech components are not under prominent dopaminergic control in PD. Treatment regimens should focus on nondopaminergic pharmacology and other therapies.     

The apomorphine test in parkinsonian syndromes.

The dopamine receptor agonist apomorphine has been used successfully to treat on-off swings in Parkinson's disease. Its value as a predictor of dopa responsiveness in idiopathic Parkinson's disease (IPD) was assessed and its potential role in differentiating IPD from the Parkinsonian plus syndromes (PPS) of multisystem atrophy, progressive supranuclear palsy and olivopontocerebellar atrophy was investigated. The response to an injection of apomorphine was observed in 20 patients with IPD and eight with PPS after being off levodopa for 12 hours. Patients were reassessed after taking levodopa for one month. Nineteen of the 20 patients (95%) with IPD showed a positive response to apomorphine and 18 (90%) to oral levodopa. In the PPS group, two patients (25%) responded to the apomorphine injection but not to oral levodopa. Apomorphine produced severe drowsiness in the PPS patients. It is suggested that the test can predict dopa responsiveness in IPD and may be of help in confirming a doubtful diagnosis. It has potential value in differentiating IPD from PPS.     

Sublingual apomorphine in the treatment of Parkinson's disease complicated by motor fluctuations.

Subcutaneous apomorphine is a useful treatment for refractory motor fluctuations in Parkinson's disease. We have now clinically evaluated a formulation of sublingual apomorphine (57 mg) and performed preliminary pharmacokinetic studies. In acute studies, all 10 patients switched "on" after a mean latency of 25 min with a mean duration of motor benefit of 118 min. In three patients followed for a mean of 4.7 months, we have shown that chronic sublingual use can be effective, safe, and convenient in controlling motor fluctuations. The pattern of clinical response followed closely the plasma profile of apomorphine with a mean Cmax of 76 pmol/ml (50-106 pmol/ml) and a mean Tmax of 60 min (45-80 min), with moderate interpatient variability in bioavailability. Sublingual apomorphine is a practical alternative to subcutaneous use in selected patients with severe motor fluctuations.     

The motor response to sequential apomorphine in parkinsonian fluctuations.

Fifteen patients with Parkinson's disease and levodopa-induced motor fluctuations, were studied with repeated injections of apomorphine using two protocols to explore possible changes in the duration of motor response. One involved different interdose intervals; in the other, doses were given when the motor effects induced by the previous dose had just worn off. No significant change in the duration of motor response to sequential subcutaneous apomorphine with either protocol was found. The results suggest that rapid changes in receptor sensitivity during repeated intermittent dopaminergic stimulation do not contribute to the pathogenesis of Parkinsonian motor fluctuations.     

A 10 year retrospective audit of long-term apomorphine use in Parkinson’s disease

Abstract Objectives Apomorphine is a potent dopamine agonist useful in the treatment of Parkinsons disease patients with disabling motor fluctuations and off periods, not responding to oral medication. It can also be of benefit in reducing dyskinesia by providing more constant dopaminergic stimulation and permitting lower levodopa dosage. However, there is a paucity of information on long-term benefits of apomorphine, including no large-scale phase III trial. We have examined our experience of apomorphine over the last 10 years, to assess indications, pattern of use, efficacy, and side effect profile. Methods All patients requiring apomorphine were identified through the Parkinsons disease Nurse Specialists records. An audit form was produced so that the same information was gathered from all case-notes. Results There were 107 patients (61 males and 46 females). Mean age of disease onset was 50.9 years, SD±9.3 (range 29–78). The mean duration of disease at start of apomorphine treatment was 10 years (SD±4.8, range2–29). The most common indications for apomorphine were severe unpredictable off periods (75.7 %), motor fluctuations (18.7 %) and dyskinesia (5.6 %). Most patients (63.6 %) used both intermittent subcutaneous injections and infusion via pump; 25.2% were on intermittent injection, and 11.2 % infusion alone. Mean dose per injection was 3.7mg. Mean infusion dose 69.8mg, running over a mean of 13.5 hours. The mean duration of intermittent apomorphine use was 48.2 months. The mean duration of infusion was 25.1 months. Complications included skin problems in 16 patients, 2 had symptomatic hypotension, 2 worsening confusion, 1 new confusion and 5 new hallucinations (after sometime on apomorphine). Sixteen patients have stopped using apomorphine completely. Thirteen have stopped the pump, but continue on intermittent injections. Conclusion Subcutaneous apomorphine is easy for patients to use, is well tolerated and has a low incidence of side effects, especially confusion.