Zydis selegiline reduces off time in Parkinson's disease patients with motor fluctuations: a 3-month, randomized, placebo-controlled study

Pharmacologic treatment of advanced Parkinson's disease: a meta-analysis of COMT inhibitors and MAO-B inhibitors

OBJECTIVE

To perform a meta-analysis of randomized placebo-controlled trials evaluating catechol-O-methyltransferase (COMT) inhibitors or monoamine oxidase type B (MAO-B) inhibitors in addition to levodopa versus levodopa alone for the treatment of advanced Parkinson's disease (PD).

METHODS

A systematic literature search was performed between 1990 and October 2007. The primary outcome measures assessed were the reduction in scores of Unified Parkinson's Disease Rating Scale (UPDRS) total, activities of daily living (ADL) and motor scores from baseline. Other efficacy and safety endpoints were also evaluated.

RESULTS

A total of 13 trials (n=3775 subjects) were included in the meta-analysis. As compared to placebo, COMT and MAO-B inhibitor use resulted in greater improvement in UPDRS total score (weighted mean difference [WMD] -2.13, 95%CI -0.46 to -0.20; and WMD -5.03, 95%CI -7.38 to -2.68) ADL scores (WMD -0.99, 95%CI -1.56 to -0.43; and WMD -1.48, 95%CI -2.13 to -0.83) and motor scores (WMD -1.50, 95%CI -2.70 to -0.30; and WMD -3.19, 95%CI -4.57 to -1.80) as well as increase in "on" time, reduction in "off" time and decreased need in levodopa dose compared to placebo. Incidences of dyskinesia were significantly higher with the COMT and MAO-B inhibitors compared to placebo.

CONCLUSION

The use of COMT or MAO-B inhibitors plus levodopa is superior to levodopa alone at reducing PD symptoms in patients with advanced PD. While combination therapies with COMT or MAO-B inhibitor plus levodopa seem especially useful amongst PD patients with wearing-off phenomenon, they are associated with more adverse events.

Orally disintegrating selegiline for the treatment of Parkinson's disease

The selective monoamine oxidase type B inhibitor selegiline is commonly administered as medical treatment to patients suffering from Parkinson's disease. The clinical value of conventional selegiline is, however, compromised by extensive first-pass metabolism, which reduces its bioavailability and leads to the production of possibly harmful methamfetamine metabolites. This review aims to evaluate a novel, orally disintegrating formulation of selegiline by examining scientific evidence from previous pharmacological and clinical studies. As a result of improved bioavailability, orally disintegrating selegiline can be administered at lower doses than conventional selegiline with similar clinical effect. It also leads to less variable selegiline blood concentrations and produces significantly less methamfetamine metabolites. We conclude that this novel formulation offers an interesting treatment option, especially for patients who report adverse events after initial treatment with conventional selegiline or who suffer from swallowing difficulties.

Medical management of motor fluctuations

Given the magnitude of the problem of motor fluctuations in patients who have Parkinson's disease treated with levodopa, a significant effort has been expended by physicians, researchers, and pharmaceutical manufacturers over the years to find effective treatments. This article briefly reviews the medical options for managing motor fluctuations that are in common use in the United States or that are expected to be available soon.

GDNF therapy for Parkinson's disease

With an increase in the aging population, the incidence of Parkinson's disease (PD), a disabling neurodegenerative disorder mainly affecting motor function, will inevitably present a challenge to an already overburdened healthcare system. Current medical and surgical therapies offer symptomatic relief but do not provide a cure. Experimental studies suggest that GDNF has the ability to protect degenerating dopamine neurons in PD as well as promote regeneration of the nigrostriatal dopamine system. However, clinical trials of GDNF infusion to date remain inconclusive. This review will examine the experimental and clinical evidence of GDNF use in PD with particular focus on its potential as an effective therapy in the treatment of PD.

Pharmacologic Options for Treatment of Levodopa-Associated ``Wearing Off''

Levodopa remains the gold standard drug for the treatment of Parkinson's disease, but the combination of disease progression and prolonged treatment can lead to ``wearing-off'' problems in the majority of patients. This constitutes the onset of motor fluctuations which includes nonmotor sensory, psychiatric, and autonomic ``off '' symptoms. There are several pharmacologic options to minimize the ``wearing-off'' phenomenon, including adjustment of levodopa treatment, the use of long-acting dopamine agonists, monoamine oxidase type B inhibition, or catechol-O-methyl-transferase inhibition in combination with levodopa. Dopamine agonists may reduce levodopa requirements. Monoamine oxidase type B inhibition can increase dopamine availability by preventing its metabolism. Similarly catechol-O-methyl-transferase inhibitors can increase the half-life of levodopa and the amount available to cross the blood-brain barrier by preventing its breakdown. The selection of a treatment for the management of ``wearing off'' should consider the relief of symptoms and also the potential adverse effects of adjunctive therapy.

The effects of antidepressants in Parkinson's disease: a meta-analysis

This study explored the therapeutic effect of antidepressants in Parkinson's disease (PD) using a meta-analysis. Altogether, 24 placebo-controlled trials qualified for inclusion and revealed that tricyclic antidepressants (TCAs) had a greater antidepressant effect relative to selective serotonin reuptake inhibitors (SSRIs), Qb(1) = 8.87, p < .01, and the mono-amine-oxidase inhibitor, selegiline, Qb(1) = 7.90, p < .01. Whereas TCAs produced a significant side effect profile (odds ratio = 3.07), adverse events were negligible with SSRIs (odds ratio = 1.83) and selegeline (odds ratio = 1.63). Antidepressants can be beneficial for patients with PD. However, the choice of antidepressants needs to take depressive symptomatologies into account while monitoring side effects.

Current status of symptomatic medical therapy in Parkinson's disease

Symptomatic medical therapies for Parkinson's disease (PD) have been disease modifying and have led to improvement in daily function, quality of life, and survival. For 40 years, these therapies have been primarily dopaminergic, and currently include the dopamine (DA) precursor levodopa (LD), DA agonists, catechol-O-methyltransferase (COMT) inhibitors, and monoamine oxidase (MAO) inhibitors. The roles of all these classes of agents have evolved, with significant changes occurring since the early 2000s. This article reviews the current literature for each of these classes of drugs, with a focus on efficacy and place in the therapeutic scheme. Levodopa is no longer considered to be toxic and, thus, its early use is not only appropriate but recommended. Ergot agonists are no longer in use, and new agents administered in patch form or subcutaneous injections have been approved. The COMT inhibitor tolcapone, with its significant efficacy, has been reintroduced, and two new MAO inhibitors have been approved. Selected safety issues are discussed, including the incidence of melanoma in relation to LD; pathological gambling and DA agonists; hepatic toxicity of tolcapone; and the tyramine or so-called cheese reaction with MAO B inhibitors. The article closes with a discussion of future directions and new drugs under development.

Medical management of levodopa-associated motor complications in patients with Parkinson's disease

Parkinson's disease is a neurodegenerative disorder that affects approximately 1% of people over the age of 60 years. Levodopa is standard, and often initial, therapy for patients with this condition; however, with continued treatment and as the disease progresses, up to 80% of patients experience 'wearing-off' symptoms, dyskinesias and other motor complications. These levodopa-associated problems may become disabling and profoundly affect quality of life. Medications commonly used to manage these symptoms include monoamine oxidase type B (MAO-B) inhibitors, catechol-O-methyltransferase (COMT) inhibitors, the NMDA receptor antagonist amantadine and dopamine receptor agonists. Agents that block MAO-B, such as rasagiline and selegiline, are used as both initial and adjunctive therapy in patients with Parkinson's disease. These medications increase concentrations of dopamine in the brain by blocking its reuptake from the synaptic cleft, a mechanism that can slow motor decline, increase 'on' time and improve symptoms of Parkinson's disease. Adverse events with these agents can include confusion, hallucination and orthostatic hypotension. MAO-B inhibition may elicit drug-drug interactions if administered with TCAs, SSRIs or SNRIs. Conventional oral selegiline is associated with potentially harmful plasma concentrations of three major amphetamine metabolites, although metabolite concentrations are significantly lower with a new orally disintegrating tablet (ODT) selegiline formulation. Selegiline ODT is also absorbed more efficiently and shows less pharmacokinetic variability than conventional oral selegiline.COMT mediates peripheral catabolism of levodopa. Therefore, agents that block COMT, such as tolcapone and entacapone, increase the elimination half-life of levodopa. Given adjunctively with levodopa, COMT inhibitors can decrease 'off' time and increase 'on' time, as well as lower the daily levodopa dose. Although more potent than entacapone, tolcapone requires monitoring for hepatotoxicity. Amantadine is a noncompetitive NMDA receptor antagonist shown to lower dyskinesia scores and improve motor complications in patients with Parkinson's disease when given adjunctively with levodopa. Dopamine agonists, also used as initial and adjunctive therapy in Parkinson's disease, improve motor response and decrease 'off' time purportedly through direct stimulation of dopamine receptors. Current dopamine agonists include bromocriptine, pergolide, cabergoline, lisuride, apomorphine, pramipexole, ropinirole and rotigotine. Although effective, this class of medications can be associated with cardiovascular and psychiatric adverse effects that can limit their utility. All medications used to manage levodopa-associated motor complications in patients with Parkinson's disease have had differing degrees of success. Although head-to-head comparisons of drugs within classes are rare, some differences have emerged related to effects on motor fluctuations, dyskinesias and on/off times, as well as to adverse effects. When choosing a drug to treat levodopa-induced complications, it is important to consider the risks and benefits of the different classes and of the specific agents within each class, given the different efficacy and safety profiles of each.

Selegiline Orally Disintegrating Tablets in Patients With Parkinson Disease and "Wearing Off" Symptoms

BACKGROUND

Selegiline orally disintegrating tablet (ODT; Zelapar) is a selective monoamine oxidase B inhibitor developed as an adjunct to levodopa (LD) for Parkinson disease. Most patients on long-term LD therapy eventually experience deterioration at the end of the LD dosing interval, with predictable "wearing off" and "on-off" fluctuations.

METHODS

We conducted a 12-week, double-blind, placebo-controlled, parallel-design trial of selegiline ODT. The primary efficacy point was reduction in the percentage of average daily "off" time. Secondary measures included reductions in daily off hours and total daily off time, Clinical Global Impressions-Improvement (CGI-I), and Patient Global Impression-Improvement (PGI-I). Patients on LD received selegiline ODT (1.25 mg/d for 6 weeks, then 2.5 mg/d for 6 weeks) or placebo. Safety and tolerability were measured.

RESULTS

The intent-to-treat population included 98 patients receiving selegiline ODT and 50 patients receiving placebo. Combined efficacy results for weeks 10 and 12 revealed an 11.6% reduction in percentage of daily off time for selegiline ODT versus a 9.8% reduction for placebo (NS). PGI-I detected a statistically significant difference between treatment groups in favor of selegiline ODT (P = 0.02), whereas CGI-I detected a strong trend toward improvement (P = 0.06). Selegiline ODT was safe and well tolerated.

CONCLUSIONS

This study showed no significant difference in improvement in percentage of off time with selegiline ODT versus placebo. Some clinical impressions (e.g., PGI-I, CGI-I) improved. This result contrasts with an identically designed study that showed a significant improvement in off time with selegiline ODT. A combined analysis of both studies suggested overall efficacy.

Monamine oxidase inhibitors: current and emerging agents for Parkinson disease

Monoamine oxidase type B (MAO-B) is the predominant isoform responsible for the metabolic breakdown of dopamine in the brain. Selective inhibition of brain MAO-B results in elevation of synaptosomal dopamine concentrations. Data have been reported regarding the selective MAO-B inhibitors, rasagiline and selegiline, for the symptomatic treatment of Parkinson disease (PD). Selegiline has demonstrated efficacy as monotherapy in patients with early PD (Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism study), but evidence of selegiline efficacy as adjunctive treatment in levodopa-treated PD patients with motor fluctuations is equivocal. A new formulation of selegiline (Zydis selegiline) has been evaluated in 2 small, placebo-controlled studies as adjunctive therapy to levodopa. The Zydis formulation allows pregastric absorption of selegiline, minimizing first-pass metabolism, and thereby increasing selegiline bioavailability and reducing the concentration of amphetamine metabolites. Rasagiline is a selective, second-generation, irreversible MAO-B inhibitor, with at least 5 times the potency of selegiline in vitro and in animal models. Rasagiline has demonstrated efficacy in 1 large, randomized, double-blind, placebo-controlled trial (TVP-1012 in Early Monotherapy for Parkinson's Disease Outpatients) as initial monotherapy in patients with early PD, and in 2 large, controlled trials (Parkinson's Rasagiline: Efficacy and Safety in the Treatment of "Off," Lasting Effect in Adjunct Therapy With Rasagiline Given Once Daily) as adjunctive treatment in levodopa-treated PD patients with motor fluctuations. Unlike selegiline, rasagiline is an aminoindan derivative with no amphetamine metabolites. A randomized clinical trial is underway to confirm preclinical and preliminary clinical data suggesting rasagiline has disease-modifying effects.

Efficacy of pramipexole and transdermal rotigotine in advanced Parkinson's disease: a double-blind, double-dummy, randomised controlled trial

BACKGROUND

Continuous dopaminergic drug delivery is an unmet medical need in advanced Parkinson's disease. The aim of this trial-Clinical Efficacy of Pramipexole And Transdermal Rotigotine in Advanced PD (CLEOPATRA-PD)-was to assess the efficacy of adjunct treatment with rotigotine in comparison with placebo and with pramipexole in levodopa-treated patients with advanced Parkinson's disease and wearing-off type motor fluctuations.

METHODS

In this randomised controlled trial, eligible participants were randomly assigned to receive either rotigotine (up to 16 mg/24 h as a transdermal patch), pramipexole (up to 4.5 mg/day orally), or placebo for 6 months. Primary efficacy variables were absolute change in total hours "off" (assessed by home diaries) from baseline to end of study and responder rate (defined as the proportion of patients with >or=30% reduction in absolute off time per day). Analyses were done by intention to treat. This trial is registered with the US National Institutes of Health clinical trials database (ClinicalTrials.gov), number NCT00244387.

FINDINGS

204 patients were randomly assigned to receive rotigotine, 201 to receive pramipexole, and 101 to receive placebo; 427 (84%) completed the trial. The number of discontinuations in each group was similar; most were for adverse events. The mean dose of rotigotine was 12.95 mg/24 h (SD 3.54), the mean dose of pramipexole was 3.1 mg/day (1.24). Mean absolute change in off time from baseline was -2.5 h (SE 0.20) with rotigotine, -2.8 h (0.20) with pramipexole, and -0.9 h (0.29) with placebo. The absolute change in off time from baseline compared with placebo was -1.58 h (95% CI -2.27 to -0.90; p<0.0001) for rotigotine and -1.94 h (-2.63 to -1.25; p<0.0001) for pramipexole. Responder rates were 67% (134 of 200 patients) for pramipexole, 59.7% (120 of 201 patients) for rotigotine, and 35% (35 of 100 patients) for placebo.

INTERPRETATION

In terms of change in absolute off time, rotigotine was non-inferior to pramipexole. Continuous delivery of rotigotine as transdermal patches could offer similar efficacy to oral pramipexole in patients with fluctuating Parkinson's disease over 6 months of treatment.

Advances in the Pharmacologic Management of Early Parkinson Disease

BACKGROUND

Levodopa, in combination with a dopa decarboxylase inhibitor, provides the greatest symptomatic benefit with the fewest short-term side effects in the treatment of Parkinson disease (PD). However, the disease continues to progress, and the long-term use of levodopa is associated with the development of motor fluctuations and dyskinesias.

REVIEW SUMMARY

Alternatives to the use of levodopa in early PD include monoamine oxidase B (MAO-B) inhibitors, dopamine agonists, and amantadine. Although no medication has been proven to slow the progression of Parkinson disease, preclinical studies have demonstrated neuroprotective effects of MAO-B inhibitors, and a recent study of rasagiline found that PD patients treated with rasagiline for 12 months experienced less progression of symptoms than patients treated with placebo for 6 months followed by rasagiline for 6 months. Several clinical trials have demonstrated that the initial use of a dopamine agonist to which levodopa can be added is associated with fewer motor complications than treatment with levodopa alone. In addition, preclinical studies suggest that adjunctive use of the catechol-O-methyltransferase (COMT) inhibitor entacapone when levodopa is first introduced may be associated with fewer motor complications than treatment with levodopa alone.

CONCLUSION

Treatment of early PD with an MAO-B inhibitor, dopamine agonist, or amantadine, may provide useful alternatives to treatment with levodopa. Adding entacapone at the initiation of levodopa therapy may reduce the development of motor complications. Long-term studies are required to evaluate the potential long-term benefits of these treatment strategies.

Safety and efficacy of newly formulated selegiline orally disintegrating tablets as an adjunct to levodopa in the management of 'off' episodes in patients with Parkinson's disease

OBJECTIVE

Patients receiving levodopa for Parkinson's disease experience motor fluctuations and immobility ('off' episodes) between doses. This study assessed adjunctive Zelapar (selegiline orally disintegrating tablet (ODT)) for managing off episodes and for long-term safety.

METHODS

This open-label extension evaluated long-term safety, efficacy, and tolerability of adjunctive selegiline ODT 2.5 mg in patients who completed either of two large phase 3 double-blind studies. The study was to end after 12 months but was amended to be open-ended. Investigators could increase levodopa doses and introduce controlled-release formulations of levodopa or dopamine agonists if warranted. Additionally, results of a small randomized trial of open-label selegiline ODT 1.25 mg in comparison to conventional selegiline was added only to the safety analysis. Efficacy variables included changes in daily off time and Patient's Global Impression of Improvement (PGI-I) and Clinical Global Impressions Severity of Disease (CGI-S) ratings. Safety assessments included adverse events and oropharyngeal findings.

RESULTS

This study enrolled 254 patients: 248 from the large phase 3 studies (efficacy analysis) and an additional six from the prior open-label comparison (safety analysis) in order to evaluate a larger population for safety purposes. Mean reduction from baseline in daily off time was 9.4% (1.6 h) for patients previously given selegiline ODT, 6.0% (1.2 h) for those switched from placebo, and 8.1% (1.4 h) overall. PGI-I and CGI-S ratings indicated little or no change from baseline. Treatment-related adverse events occurred in 132 (52%) patients. No severe oral irritations were attributed to selegiline ODT or prompted discontinuation.

CONCLUSIONS

Long-term selegiline ODT 2.5 mg/day was effective, safe, and well tolerated in patients with Parkinson's disease experiencing off episodes during levodopa therapy.

Balancing short-term symptom control and long-term functional outcomes in patients with Parkinson's disease

Levodopa has played a central role in the treatment of Parkinson's disease for nearly 40 years and remains the single most effective symptomatic treatment for the disease. However, the response to levodopa therapy changes over time, and its long-term use is commonly associated with disabling motor complications. For this reason, the appropriate role of levodopa in the treatment of Parkinson's disease-in particular, the question of when to initiate therapy with the drug-has been a matter of controversy. Because levodopa is the most effective treatment for Parkinson's disease, the management of this disease becomes a matter of balancing short-term symptom control with long-term functional outcomes. This article provides an overview of the basis for levodopa-associated motor complications and their impact on patients' clinical function and quality of life, followed by a discussion of strategies for managing these complications to achieve optimum symptom control while minimizing the adverse effects of long-term therapy.

Community and Long-Term Care Management of Parkinson???s Disease in the Elderly

Parkinson's disease affects up to 1 million people in the US, most of them elderly. Motor and non-motor symptoms can be significantly disabling to the point of necessitating institutionalisation. Age-related changes in drug absorption, distribution, metabolism and excretion complicate the treatment of elderly patients with Parkinson's disease. General management principles include initiation of medication at low doses with gradual titration based on clinical effects, avoidance of certain classes of drugs (e.g. anticholinergics), and attention to polypharmacy and its risk for potentially toxic drug interactions. Levodopa remains the most efficacious anti-Parkinson's disease medication and should be the cornerstone of therapy in the elderly Parkinson's disease patient. Use of dopamine receptor agonists, amantadine and anticholinergic drugs in the elderly is limited by high risk for psychotoxicity. Catechol-O-methyltransferase inhibitors may be used to augment levodopa in the setting of 'wearing off' (i.e. motor fluctuations). Monoamine oxidase type B (MAO-B) inhibitors can be used across the spectrum of disease severity, but selegiline (deprenyl), the prototype in this class, is characterised by low and erratic bioavailability of the parent drug and conversion to amphetamine metabolites that may increase the risk of adverse events. A new orally disintegrating tablet formulation overcomes some of these limitations. Rasagiline is a new, selective, second-generation MAO-B inhibitor that is chemically and metabolically distinct from selegiline. The favourable safety profile of rasagiline in the elderly and its once-daily formulation may maximise drug adherence and improve outcomes.

Review of the therapeutic management of Parkinson's disease. Report of a joint task force of the European Federation of Neurological Societies (EFNS) and the Movement Disorder Society-European Section (MDS-ES). Part II: late (complicated) Parkinson's disease

To provide evidence-based recommendations for the management of late (complicated) Parkinson's disease (PD), based on a review of the literature. Complicated PD refers to patients suffering from the classical motor syndrome of PD along with other motor or non-motor complications, either disease-related (e.g. freezing) or treatment-related (e.g. dyskinesias or hallucinations). MEDLINE, Cochrane Library and INAHTA database literature searches were conducted. National guidelines were requested from all EFNS societies. Non-European guidelines were searched for using MEDLINE. Part II of the guidelines deals with treatment of motor and neuropsychiatric complications and autonomic disturbances. For each topic, a list of therapeutic interventions is provided, including classification of evidence. Following this, recommendations for management are given, alongside ratings of efficacy. Classifications of evidence and ratings of efficacy are made according to EFNS guidance. In cases where there is insufficient scientific evidence, a consensus statement ('good practice point') is made.

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.

Emerging drugs for Parkinson’s disease

Parkinson's disease (PD) afflicts millions of people worldwide. There are numerous drugs available for PD; however, levodopa remains the gold standard of pharmacotherapy to which all other therapies are compared. Levodopa is quite effective for many motor symptoms (bradykinesia, tremor, rigidity) of PD; however, non-levodopa-responsive motor symptoms (postural instability) and nonmotor symptoms are frequently the most troublesome in middle and later stages of disease. Although motor symptoms remain an important focus for emerging drugs, current research is largely geared to identify and develop disease-slowing therapies. Another important area of focus has become treatment of the nonmotor symptoms of PD (especially depression and dementia). This review discusses emerging drugs in the management of the motor and nonmotor symptoms of PD and drugs under study as disease-slowing/neuroprotective agents.

Initial treatment of Parkinson's disease

Initial treatment of early idiopathic Parkinson's disease (PD) begins with diagnosis based on clinical evaluation supplemented by laboratory studies and brain imaging to exclude causes of secondary parkinsonism. In most cases, testing is normal and the diagnosis of PD rests on clinical criteria. In patients with mild symptoms and signs, the diagnosis of PD may not initially be apparent, and follow-up evaluation is needed to arrive at a diagnosis. Once the diagnosis is made, pharmacologic treatment may not be the first step. First, patient education is essential, especially because PD is a high-profile disease for which information and misinformation are readily available to patients and families. Counseling concerning prognosis, future symptoms, future disability, and treatment must be provided. Questions from patients concerning diet, lifestyle, and exercise are especially common at this point. The decision of when to initiate treatment is the next major consideration. Much controversy but relatively little light has been brought to bear on this issue. L-dopa was the first major antiparkinson medication to be introduced and remains the "gold standard" of treatment. Next in efficacy are the dopamine agonists (DAs). A debate has raged concerning whether initial dopaminergic treatment should be with L-dopa or DAs. Physicians have been concerned about forestalling the appearance of dyskinesias and motor fluctuations, whereas patients have incorrectly understood that L-dopa and possibly other antiparkinson drugs have a finite duration of usefulness, making it important to defer treatment for as long as possible. This has created "L-dopa phobia," which may stand in the way of useful treatment. In spite of this controversy, there is uniform agreement that the appropriate time to treat is when the patient is beginning to be disabled. This varies from patient to patient and depends on age, employment status, nature of job, level of physical activity, concern about appearance, and other factors. The choice of a specific drug is sometimes dictated by the patient's symptoms. For example, L-dopa is preferable for severe akinesia, an anticholinergic may be useful when tremor is the most prominent symptom (especially in those aged younger than 70 years), and DAs may be indicated for younger patients, more prone to dyskinesias and fluctuations, with relatively mild symptoms. It is also important to manage non-motor symptoms in patients with early PD. Anxiety and depression are particularly common at this stage and may be presenting symptoms of PD. Where appropriate, counseling and/or treatment with anxiolytics and antidepressants should be considered.

Selegiline orally disintegrating tablets for the treatment of Parkinson's disease

Selegiline orally disintegrating tablet is a potent, selective and irreversible inhibitor of monoamine oxidase type B. It is delivered in an innovative formulation that largely bypasses the gut and first-pass hepatic metabolism by allowing transbuccal absorption. Selegiline orally disintegrating tablet dissolves in the mouth within seconds and is rapidly absorbed directly into the systemic circulation, increasing parent drug bioavailability and lowering plasma metabolites compared with conventional oral formulations. Adding selegiline orally disintegrating tablet to levodopa in patients experiencing 'wearing-off' episodes significantly decreases off time and increases dyskinesia-free 'on' time. Adding selegiline orally disintegrating tablet to levodopa also significantly improves Unified Parkinson's Disease Rating Scale motor scores and patients' and physicians' ratings of disease severity. Selegiline orally disintegrating tablet has been demonstrated to be safe and well tolerated in placebo-controlled clinical trials.

[Olanzapine use in cancer patients for refractory vomiting]

Recent investigations suggest the efficacy of olanzapine in cancer patients with intractable vomiting or chemotherapy-induced nausea. Olanzapine,indicated for schizophrenia in Japan, has an affinity for multiple neurotransmitter receptors including dopaminergic, serotonergic, histaminergic, adrenergic and muscarinic receptors. This pharmacological activity thus has a potential role in the treatment of nausea and vomiting. In the present study, olanzapine was given to five cancer patients with refractory vomiting to standard medications. In 3 cases, olanzapine resolved vomiting completely and also improved anorexia, In 2 cases, vomiting was controlled for a limited period. No adverse effect was observed. These results suggest olanzapine is a useful agent for the management of both vomiting and anorexia.

Orally disintegrating carbidopa/levodopa

To date, pharmacological treatment of Parkinson’s disease has been symptomatic. Available agents serve to either increase striatal dopamine activity (e.g., levodopa, dopamine agonists, monoamine oxidase inhibitors, catechol-O-methyl transferase inhibitors and amantadine) or decrease acetylcholine activity. Orally disintegrating carbidopa/levodopa tablets provide bioequivalent carbidopa/levodopa in an alternative dosage form that patients prefer. The orally disintegrating tablets are useful for patients who cannot swallow a traditional oral tablet formulation and are convenient for those who do not have access to water when they need to take a dose of medication.

Rasagiline: defining the role of a novel therapy in the treatment of Parkinson's disease

Parkinson's disease (PD) is a therapy area with considerable unmet needs. The current key targets for PD treatment include the slowing of disease progression, improved control of motor fluctuations in advanced disease and the treatment of non-motor symptoms. In view of such major requirements, it is important to consider how new drug treatments fit into the context of PD therapy, and the practical advantages that they may offer in the management of PD in clinical practice. Rasagiline is a novel, second-generation, irreversible, selective monoamine oxidase type B inhibitor that is indicated for the treatment of idiopathic PD, either as initial monotherapy or as adjunct therapy (with levodopa) for patients experiencing end-of-dose motor fluctuations. This review assesses the outcome from several large-scale clinical studies that have investigated the use of rasagiline in early and advanced PD patient populations and discusses the role of rasagiline within the current scope of PD therapy.

[Medication treatment for Parkinson's disease]

In general, therapy for Parkinson's disease is dominated by dopamine agonists (DA) in younger patients and levodopa in older patients with comorbidities. Single or combined treatment with DA should be used as long as possible to avoid levodopa and associated complications. About 30% of our patients respond to DA monotherapy and tolerate it for quite a long time. It is important to sustain patient confidence. Although parkinsonism is an insidious disease of unknown cause resulting in destruction of important dopaminergic neurons, no other neurodegenerative disease can be treated as successfully.

Treatment of motor dysfunction in Parkinson's disease: an overview

Levodopa remains the most effective treatment for Parkinson's disease (PD). However, the use of this drug is complicated by several adverse effects, in particular motor fluctuations and dyskinesias. Drugs providing more continuous dopaminergic stimulation and surgical approaches, such as deep-brain stimulation, have an important ameliorative effect on these problems. Despite these advances, the progression of the disease remains unaffected and strategies that slow or stop the neurodegenerative process are currently not available. Nevertheless, several compounds or surgical procedures are candidates for being neuroprotective and some of them are under evaluation.

Strategies to improve oral drug bioavailability

Efforts to improve oral drug bioavailability have grown in parallel with the pharmaceutical industry. As the number and chemical diversity of drugs has increased, new strategies have been required to develop orally active therapeutics. The past two decades have been characterised by an increased understanding of the causes of low bioavailability and a great deal of innovation in oral drug delivery technologies, marked by an unprecedented growth of the drug delivery industry. The advent of biotechnology and consequent proliferation of biopharmaceuticals have brought new challenges to the drug delivery field. In spite of the difficulties associated with developing oral forms of this type of therapeutics, significant progress has been made in the past few years, with some oral proteins, peptides and other macromolecules currently advancing through clinical trials. This article reviews the approaches that have been successfully applied to improve oral drug bioavailability, primarily, prodrug strategies, lead optimisation through medicinal chemistry and formulation design. Specific strategies to improve the oral bioavailability of biopharmaceuticals are also discussed.

Other pharmacological treatments for motor complications and dyskinesias

Controlling motor complications becomes increasingly difficult with disease progression. The "wearing-off" phenomenon is the most-common motor fluctuation. Wearing-off can be treated by dietary manipulation, shortening the dosing interval, substituting sustained-release levodopa, adding amantadine, or monoamine oxidase type B inhibitors, and other options, including catechol-O-methyltransferase inhibitors and the approved dopamine agonists addressed in another chapter. The rotigotine constant-delivery system is being developed to treat wearing-off symptoms. Istradefylline (KW-6002), an adenosine A(2A) receptor antagonist, has been studied for wearing-off and the results will be discussed. The on-off fluctuations can be treated with liquid levodopa and the rescue therapy of injectable apomorphine. Patients may also suffer from dyskinesias. Dyskinesias can be treated with small doses of liquefied levodopa-carbidopa, amantadine, and clozapine, an atypical neuroleptic.

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.