Potential of transdermal drug delivery in Parkinson's disease

Rotigotine vs ropinirole in advanced stage Parkinson's disease: a double-blind study

OBJECTIVE

To confirm the superiority of transdermal rotigotine up to 16 mg/24 h over placebo, and non-inferiority to ropinirole, in Japanese Parkinson's disease (PD) patients on concomitant levodopa therapy.

METHODS

This trial was a randomized, double-blind, double-dummy, three-arm parallel group placebo- and ropinirole-controlled trial. Four-hundred and twenty PD patients whose motor symptoms were not well controlled by levodopa treatment were randomized 2:2:1 to receive rotigotine, ropinirole (up to 15 mg/day) or placebo during a 16-week treatment period followed by a 4-week taper period. The primary variable was change in the Unified Parkinson's Disease Rating Scale (UPDRS) Part III (ON state) sum score from baseline to the end of the treatment period.

RESULTS

The difference in the change in the UPDRS Part III (ON state) sum score from baseline to the end of treatment between rotigotine and placebo groups was -6.4 ± 1.2 (95% CI: -8.7 to -4.1; p < 0.001), indicating superiority of rotigotine over placebo. The difference between rotigotine and ropinirole groups was -1.4 ± 1.0 (95% CI: -3.2 to 0.5), below the non-inferiority margin, indicating the non-inferiority of rotigotine to ropinirole. Application site reaction was seen in 57.7% of the patients in the rotigotine group and in 18.6% in the ropinirole group (P < 0.001). No other safety issue was noted.

CONCLUSIONS

Rotigotine was well tolerated at doses up to 16 mg/24 h and showed similar efficacy to ropinirole except that the application site reaction was much higher in the rotigotine group.

Transdermal rotigotine in advanced Parkinson's disease: a randomized, double-blind, placebo-controlled trial

Rotigotine, a non-ergot dopamine receptor agonist, offers potential for continuous dopaminergic stimulation that could avoid the fluctuations observed with traditional treatments. We conducted a randomized, double-blind, placebo-controlled trial in Japanese patients with advanced Parkinson's disease (PD) to investigate the efficacy and safety of rotigotine. Inclusion criteria included the presence of motor complications, such as wearing off, on-off, delayed-on/no-on, any circumstances that could interfere with levodopa dose escalation because of side effects, or declining levodopa efficacy. The enrolled patients received once-daily applications of rotigotine transdermal patches or matched placebo patches. A total of 174 patients were randomly assigned to rotigotine (87 patients) or placebo (87 patients). The full analysis set included 172 patients (86 for the rotigotine group and 86 for the placebo group). The maximum maintenance dose of rotigotine was set at 16 mg/24 h. The changes in unified PD rating scale Part III scores from baseline to the end of the trial were -10.1 ± 9.0 (mean ± standard deviation) in the rotigotine group and -4.4 ± 7.4 in the placebo group (p < 0.001). There was a significantly greater reduction in the off-time (p = 0.014) in the rotigotine group. Rotigotine was well tolerated, with serious adverse events being reported in only three patients in each group. Rotigotine at doses of up to 16 mg/24 h is efficacious and safe in Japanese patients with advanced PD.

An update on the management of young-onset Parkinson's disease

In the text that follows, we review the main clinical features, genetic characteristics, and treatment options for Parkinson's disease (PD), considering the age at onset. The clinical variability between patients with PD points at the existence of subtypes of the disease. Identification of subtypes is important, since a focus on homogenous group may lead to tailored treatment strategies. One of the factors that determine variability of clinical features of PD is age of onset. Young-onset Parkinson's disease (YOPD) is defined as parkinsonism starting between the ages of 21 and 40. YOPD has a slower disease progression and a greater incidence and earlier appearance of levodopa-induced motor complications; namely, motor fluctuations and dyskinesias. Moreover, YOPD patients face a lifetime of a progressive disease with gradual worsening of quality of life and their expectations are different from those of their older counterparts. Knowing this, treatment plans and management of symptoms must be paid careful attention to in order to maintain an acceptable quality of life in YOPD patients.

Therapeutic options for continuous dopaminergic stimulation in Parkinson's disease

Treatment of Parkinson's disease aims to replace dopaminergic transmission at striatal synapses. In the normal state, nigral neurons fire continuously, exposing striatal dopamine receptors to relatively constant levels of dopamine. In the disease state, periodic dosing and the short half-life of antiparkinsonian drugs leads to more intermittent stimulation. Abnormal pulsatile stimulation of striatal dopamine receptors may lead to dysregulation of genes and proteins in downstream neurons and consequently, alterations in neuronal firing patterns. This may ultimately lead to motor complications. In order to prevent the development of motor complications a therapy that provides continuous dopaminergic stimulation as observed in the normal state would be ideal. Different routes of administration of levodopa and other dopaminergic drugs have been tried to achieve continuous dopaminergic stimulation (CDS). This review discusses the various methods available to achieve this goal with particular emphasis on duodenal dopa administration.

Advances in the treatment of Parkinson's disease

Parkinson's disease (PD) affects one in every 100 persons above the age of 65 years, making it the second most common neurodegenerative disease after Alzheimer's disease. PD is a disease of the central nervous system that leads to severe difficulties with body motions. The currently available therapies aim to improve the functional capacity of the patient for as long as possible; however they do not modify the progression of the neurodegenerative process. The need for newer and more effective agents is consequently receiving a great deal of attention and consequently being subjected to extensive research. This review concisely compiles the limitations of currently available therapies and the most recent research regarding neuroprotective agents, antioxidants, stem cell research, vaccines and various surgical techniques available and being developed for the management of PD.

Transdermal treatment options for neurological disorders: impact on the elderly

As people grow old, their need for medications increases dramatically because of the higher incidence of chronic pain, diabetes mellitus, cardiovascular and neurological diseases in the elderly population. Furthermore, the elderly require special consideration with respect to drug delivery, drug interactions and adherence. In particular, patients with chronic neurological diseases often require multiple administration of drugs during the day to maintain constant plasma medication levels, which in turn increases the likelihood of poor adherence. Consequently, several attempts have been made to develop pharmacological preparations that can achieve a constant rate of drug delivery. For example, transdermal lisuride and apomorphine have been shown to reduce motor fluctuations and duration of 'off' periods in advanced Parkinson's disease, while rotigotine allows significant down-titration of levodopa without severe adverse effects. Thus, parkinsonian patients with long-term levodopa syndrome or motor disorders during sleep could benefit from use of transdermal lisuride and apomorphine. Moreover, transdermal dopaminergic drugs, particularly rotigotine, seem the ideal treatment for patients experiencing restless legs syndrome or periodic limb movement disorder during sleep, disorders that are quite common in elderly people or in association with neurodegenerative diseases. Unlike dopaminergic drugs, transdermal treatments for the management of cognitive and behavioural dysfunction in patients with Parkinson's disease and Alzheimer's disease have inconsistent effects and no clearly established role. Nevertheless, because of their favourable pharmacological profile and bioavailability, the cholinesterase inhibitors tacrine and rivastigmine are expected to show at least the same benefits as oral formulations of these drugs, but with fewer severe adverse effects. Transdermal delivery systems play an important role in the management of neuropathic pain. The transdermal lidocaine (lignocaine) patch is recommended as first-line therapy for the treatment of postherpetic neuralgia. Furthermore, in patients with severe persistent pain, transdermal delivery systems using the opioids fentanyl and buprenorphine are able to achieve satisfactory analgesia with good tolerability, comparable to the benefits seen with oral formulations. Transdermal administration is the ideal therapeutic approach for chronic neurological disorders in elderly people because it provides sustained therapeutic plasma levels of drugs, is simple to use, and may reduce systemic adverse effects. Several transdermal delivery systems are currently under investigation for the treatment of Parkinson's disease, Alzheimer's disease and neuropathic pain. Although most transdermal delivery systems treatments cannot be considered as first-line therapy at present, some of them provide clear advantages compared with other routes of administration and may become the preferred treatment in selected patients. In general, however, most transdermal treatments still require long-term evaluation in large patient groups in order to optimise dosages and evaluate the actual incidence of local and systemic adverse effects.

Advances in the delivery of treatments for Parkinson's disease

Innovative drug delivery in Parkinson's disease (PD) has the potential to reduce or avoid many side effects of current treatment, such as wearing-off type fluctuations, dyskinesia, on-off phenomena or bouts of motor freezing. The traditional orally administered formulations of l-dihydroxyphenylalanine combined with a peripheral aromatic acid decarboxylase inhibitor remain the mainstay of treatments for PD. However, such combination therapies have been further formulated to extend their duration of action by including a catechol-O-methyltransferase inhibitor. Preventing the breakdown of dopamine has also been achieved by monoamine oxidase-B inhibition; this approach now having been formulated for sublingual use (Zelapar, Valeant Pharmaceuticals). An alternative approach bypasses the oral route of administration and instead relies on continuous duodenal infusion (Duodopa, Solvay, NeoPharma AB) for better therapeutic effect. The clinical use of dopamine agonists as antiparkinsonian drugs now incorporates a variety of delivery techniques. For example, apomorphine, which relies on parenteral administration for maximum bioavailability, may be delivered via rectal, intranasal, sublingual and subcutaneous (e.g., Apokyn, Mylan Bertek) routes. Meanwhile, rotigotine and lisuride have both been formulated for delivery via skin patches. Finally, the authors examine more experimental delivery techniques, including the delivery of genes via viral vectors or liposomes, intracranial transplant of a variety of cells and of L-dihydroxyphenylalanine by prodrug-dispensing liposomes or pulmonary delivery (AIR, Alkermes). The advent and application of these varied technologies will help encourage patient-specific means of treatment for PD.

Rotigotine Transdermal Patch Enables Rapid Titration to Effective Doses in Advanced-Stage Idiopathic Parkinson Disease

OBJECTIVE

Rotigotine (Neupro) is formulated as a transdermal delivery system designed to provide a selective, non-ergot D3/D2/D1 agonist to the systemic blood flow over a 24-hour period. In clinical trials, patches were applied once daily and uptitrated to the individual effective dose in increments of 2 mg/24 h every week. The aim of this analysis was to determine the safety of a more rapid titration of rotigotine by assessing the tolerability of escalating transdermal doses of rotigotine given in 2 different titration schemes.

METHODS

We analyzed the safety of rotigotine in 2 groups of patients with advanced stage Parkinson Disease. The starting dose of 4 mg/24 h was increased every week by 2 mg/24 h in the slow-titration group and 4 mg/24 h in the fast-titration group. The primary focus of this subanalysis was the separate tolerability of rotigotine in each randomized treatment arm, during the dose-escalation period. However, the 2 titration schemes were also compared with each other.

RESULTS

The dose of first reported nausea and/or vomiting was 8 mg/24 h for the fast-titration group and 4 mg/ 24 h for the slow-titration group. There were no remarkable differences concerning the side-effect profile between the 2 different titration schemes.

CONCLUSIONS

The fast-titration regimen had a similar adverse event profile to slower titration, and allowed rotigotine to be introduced quickly. This subanalysis suggests that rotigotine may be uptitrated more rapidly.

Pharmacokinetic optimisation in the treatment of Parkinson's disease : an update

Pharmacotherapy for Parkinson's disease is focused on dopaminergic drugs, mainly the dopamine precursor levodopa and dopamine receptor agonists. The elimination half-life (t(1/2)) of levodopa from plasma (in combination with a decarboxylase inhibitor) of about 1.5 hours becomes more influential as the disease progresses. The long-duration of response to levodopa, which is evident in early Parkinson's disease, diminishes and after a few years of treatment motor performance is closely correlated to the fluctuating plasma concentrations of levodopa. Absorption of levodopa in the proximal small intestine depends on gastric emptying, which is erratic and may be slowed in Parkinson's disease. The effects of levodopa on motor function are dependent on gastric emptying in patients in the advanced stages of disease. The current treatment concept is continuous dopaminergic stimulation (CDS). Sustained-release formulations of levodopa may provide more stable plasma concentrations. Oral liquid formulations shorten the time to reach peak concentration and onset of effect but do not affect plasma levodopa variability. The t(1/2) of levodopa can be prolonged by adding a catechol-O-methyltransferase inhibitor (entacapone or tolcapone), which may reduce fluctuations in plasma concentrations, although both peak and trough concentrations are increased with frequent administration. Intravenous and enteral (duodenal/jejunal) infusions of levodopa yield stable plasma levodopa concentrations and motor performance. Enteral infusion is feasible on a long-term basis in patients with severe fluctuations. Among the dopamine receptor agonists the ergot derivatives bromocriptine, cabergoline, dihydroergocryptine and pergolide, and the non-ergot derivatives piribedil, pramipexole and ropinirole, have longer t(1/2) compared with levodopa. Thus, they stimulate dopamine receptors in a less pulsatile manner, yet pharmacokinetic studies of repeated doses of dopamine receptor agonists are few. Optimisation of these drugs is often performed with standardised titration schedules. Apomorphine and lisuride have short t(1/2) and are suitable for subcutaneous infusion, with results similar to those of levodopa infusion. Transdermal administration of dopamine receptor agonists such as rotigotine might be an alternative in the future. In general, initial dopamine receptor agonist monotherapy is associated with poorer motor performance and lower incidence of motor complications compared with levodopa. Buccal administration of the monoamine oxidase-B inhibitor selegiline (deprenyl) provides better absorption and less formation of metabolites compared with standard tablets. To conclude, several new drugs, formulations and routes of administration have been introduced in the treatment of Parkinson's disease during the last decade, mainly with CDS as the aim. CDS can be approached by optimising the use of dopaminergic drugs based on pharmacokinetic data.

Alternatives to Levodopa in the Initial??Treatment of Early Parkinson???s Disease

Parkinson's disease (PD) is primarily a disease of elderly patients. This article reviews current knowledge and recent developments relating to drugs that can be used as alternatives to levodopa as initial treatment of PD. Synthetic orally acting dopamine agonists have found increasing favour as an option for early PD in relatively young patients. This strategy is based on evidence that this approach may delay the onset of motor fluctuations, at least during the first 5 years of treatment. Subcutaneous apomorphine infusions may attenuate motor fluctuations in late-stage disease, and transdermal rotigotine, a dopamine agonist in development, has also been shown to be efficacious. The greater proclivity for dopamine agonists to cause psychotoxicity has, however, limited their routine use in the elderly. Selective monoamine oxidase type B (MAO-B) inhibitors, used as monotherapy, delay the need for the introduction of levodopa by about 9 months. These agents appear to be less efficacious than dopamine agonists but are better tolerated. Concern has been expressed about the potential of the MAO-B inhibitor selegiline (deprenyl) to induce cardiovascular adverse effects (orthostatic hypotension), either directly or through its amphetamine catabolites. Rasagiline is a new MAO-B inhibitor that is not broken down to amphetamine derivatives and is indicated as both monotherapy in early PD and as adjunctive therapy in PD patients with motor fluctuations. Two older classes of agents have undergone a resurgence of interest in recent years. Amantadine, which enhances dopaminergic transmission and has antiglutamate activity, is occasionally used as monotherapy but has recently been widely used as an antidyskinetic agent in late-stage PD. Anticholinergic drugs, such as benztropine (benzatropine) and orphenadrine also provide control of symptoms when used as monotherapy, but their psychotoxic, cognitive and autonomic adverse events make them inappropriate for the treatment of the elderly. Effective therapy in PD should prevent disease progression and abolish motor and cognitive handicap. Currently, none of the existing drugs meets all these needs.

Transdermal lisuride delivery in the treatment of Parkinson's disease

Transdermal delivery of dopamine agonists (DA) is a promising therapeutic concept, which aims to ameliorate frequency and intensity of motor fluctuations in patients with Parkinson's disease (PD). We treated 8 PD patients with unpredictable on-off phenomena with lisuride patches (release: 2-5 microg lisuride base/cm2/hour in mice) in addition to their preexisting antiparkinsonian drug regime up to a period of 8 days. In order to quantify the intensity and frequency of motor fluctuations, we determined the motor changing rate (MCR), which corresponds to the patient's self rating of motor function, performed every thirty minutes, divided through the number of scored intervals minus 1. Additional lisuride patch application significantly (p = 0.023) improved the MCR compared to baseline. Relevant side effects were transient skin irritations in four patients. Our observational study demonstrates the safety, tolerability and efficacy of transdermal lisuride delivery in the treatment of motor complications.