Treatment of subcutaneous nodules after infusion of apomorphine; a biopsy-controlled study comparing 4 frequently used therapies.

This study aimed to provide clinical evidence for existing treatments of subcutaneous nodules after subcutaneous infusion of apomorphine, using a biopsy-controlled prospective crossover design of four treatments. We demonstrated that dilution of apomorphine significantly improved patient satisfaction, while subcutaneous hydrocortisone reduced nodule size, however with no differences in the histopathology.

Cost-Effectiveness of Device-Aided Therapies in Parkinson's Disease: A Structured Review.

BACKGROUND: Despite optimal dopaminergic treatment most patients in moderate to advanced stages of Parkinson's disease (PD) experience progressively increasing disabilities, necessitating a shift from oral medication to device-aided therapies, including deep brain stimulation (DBS), intrajejunal levodopa-carbidopa infusion (IJLI), and continuous subcutaneous apomorphine infusion (CSAI). However, these therapies are costly, limiting their implementation. OBJECTIVES: To perform a systematic review on cost-effectiveness analyses for device-aided therapies in PD. METHODS: References were identified by performing a systematic search in the PubMed and Web of Science databases in accordance with the PRISMA statement. In the absence of universal cost-effectiveness definitions, the gross domestic product per capita (GDP) in the country where a study was performed was used as a cut-off for cost-effectiveness based on cost per quality adjusted life year (QALY) gained. RESULTS: In total 30 studies were retrieved. All device-aided therapies improved quality of life compared to best medical treatment, with improvements in QALYs between 0.88 and 1.26 in the studies with long temporal horizons. For DBS, nearly all studies showed that cost per QALY was below the GDP threshold. For infusion therapies only three studies showed a cost per QALY below this threshold, with several studies with long temporal horizons showing costs below or near the GDP threshold. CONCLUSION: Of the device-aided therapies, DBS can be considered cost-effective, but the majority of infusion therapy studies showed that these were less cost-effective. However, long-term use of the infusion therapies appears to improve their cost-effectiveness and in addition, several strategies are underway to reduce these high costs.

Neuroprotective Effects of Safflower Flavonoid Extract in 6-Hydroxydopamine-Induced Model of Parkinson's Disease May Be Related to its Anti-Inflammatory Action.

Safflower (Carthamus tinctorius. L.), a Chinese materia medica, is widely used for the treatment of cardiovascular and cerebrovascular diseases, with flavonoids being the major active components. Multiple flavonoids in safflower bind to Parkinson's disease (PD)-related protein DJ-1. Safflower flavonoid extract (SAFE) improved behavioral indicators in a 6-hydroxydopamine (6-OHDA)-induced rat model of PD; however, the underlying mechanisms remain unclear. We used a 6-OHDA-induced mouse model of PD and a primary neuron-astrocyte coculture system to determine the neuroprotective effects and mechanisms of SAFE. After three weeks of SAFE administration, behavioral indicators of PD mice were improved. SAFE regulated the levels of tyrosine hydroxylase (TH) and dopamine metabolism. It significantly inhibited the activation of astrocytes surrounding the substantia nigra and reduced Iba-1 protein level in the striatum of PD mice. SAFE reduced the plasma content of inflammatory factors and suppressed the activation of nod-like receptor protein 3 (NLRP3) inflammasome. In the coculture system, kaempferol 3-O-rutinoside and anhydrosafflor yellow B significantly improved neuronal survival, suppressed neuronal apoptosis, and reduced IL-1ß and IL-10 levels in the medium. Thus, SAFE showed a significant anti-PD effect, which is mainly associated with flavonoid anti-inflammatory activities.

Nucleophilic Addition in Aqueous Apomorphine Formulation Solutions in the Presence of Sodium Metabisulfite: Implications for Formulation Development and Manufacturing.

The purpose of this study was to investigate a potential nucleophilic addition mechanism in aqueous apomorphine formulation solutions in the presence of widely used antioxidants such as sodium metabisulfite (Na2S2O5). The findings of this investigation provide insights into how sodium metabisulfite can influence the formation of particulate under the conditions leading to the auto-oxidation of apomorphine to apomorphine orthoquinone. The addition products resulting from the reaction of bisulfite nucleophile on apomorphine orthoquinone in a Michael addition fashion were identified and characterized using ultraviolet-visible spectroscopy and mass spectrometry.

New Dopamine D2 Receptor Agonist, [3H]MCL-536, for Detecting Dopamine D2high Receptors in Vivo.

Increases in the D2 receptor high affinity state are associated with certain neurological disorders. We synthesized and characterized the high-affinity D2high ligand [3H]MCL-536 in competition binding against the D2/3 agonist R-(-)- N- n-propylnorapomorphine (NPA) and the D2/3 antagonist raclopride. The total binding of [3H]MCL-536 (minus that in the presence of 100 nM NPA) was measured by saturation binding in CHO cells expressing human D2long; the data yielded separable, nonsaturable nonspecific, and saturable specific components. The former represents an aporphine site common to NPA and [3H]MCL-536. The latter indicated specific binding to the total D2 receptors (both high and low-affinity states). [3H]MCL-536 had a Kd of 0.8 nM. In competition binding, NPA had a Ki of 0.16 nM, and raclopride had a Ki of 0.9 nM. Co-incubation with guanylylimidodiphosphate abolished binding to D2high. This unique profile makes radiolabeled MCL-536 a versatile tool for diagnostics and therapeutics, and may quantify D2high sites in schizophrenia and PD patients in vivo.

Mechanistic analyses of the suppression of amyloid ß42 aggregation by apomorphine.

(R)-Apomorphine (1) has the potential to reduce the accumulation of amyloid ß-protein (Aß42), a causative agent of Alzheimer's disease (AD). Although the inhibition of Aß42 aggregation by 1 is ascribable to the antioxidative effect of its phenol moiety, its inhibitory mechanism at the molecular level remains to be fully elucidated. LC-MS and UV analyses revealed that 1 is autoxidized during incubation to produce an unstable o-quinone form (2), which formed a Michael adduct with Lys 16 and 28 of Aß42. A further autoxidized form of 1 (3) with o-quinone and phenanthrene moieties suppressed Aß42 aggregation comparable to 1, whereas treating 1 with a reductant, tris(2-carboxyethyl)phosphine diminished its inhibitory activity. 1H-15N SOFAST-HMQC NMR studies suggested that 1 interacts with Arg5, His13,14, Gln15, and Lys16 of the Aß42 monomer. These regions form intermolecular ß-sheets in Aß42 aggregates. Since 3 did not perturb the chemical shift of monomeric Aß42, we performed aggregation experiments using 1,1,1,3,3,3-hexafluoro-2-propanol-treated Aß42 to investigate whether 3 associates with Aß42 oligomers. Compounds 1 and 3 delayed the onset of the oligomer-driven nucleation phase. Despite their cytotoxicity, they did not exacerbate Aß42-mediated neurotoxicity in SH-SY5Y neuroblastoma cells. These results demonstrate that extension of the conjugated system in 1 by autoxidation can promote its planarity, which is required for intercalation into the ß-sheet of Aß42 nuclei, thereby suppressing further aggregation.

Efficacy of oral lipid-based formulations of apomorphine and its diester in a Parkinson's disease rat model.

OBJECTIVES: Apomorphine is used to symptomatically treat Parkinson's disease (PD). Oral delivery of apomorphine is generally limited by its short plasma half-life and a hepatic first-pass metabolism. This study was aimed at evaluating the behavioural response of apomorphine and its prodrug administered in oral lipid-based formulations. METHODS: The behavioural response of apomorphine and its prodrug administered in oral lipid-based formulations was evaluated using a 6-hydroxydopamine-lesioned rat model simulating PD symptomatology. Apomorphine or dipalmitoyl apomorphine (DPA) was incorporated into different lipid-based formulations and orally administered (0.24 mmol/kg) to the PD rat model. The rotations by the rats were counted. KEY FINDINGS: The duration of response lasted to about 2.5 h with oral apomorphine- and DPA-loaded o/w emulsion, while it was increased to 6 h when DPA was incorporated in self-emulsifying drug delivery systems compared to s.c. apomorphine (1 h). This suggests that the lipid-based formulations provide a sustained drug release allowing for a steady exposure to the brain. CONCLUSIONS: Oral lipid-based apomorphine delivery has a potential in achieving a steady response, though at a higher dose possibly eliminating the need for frequent s.c. apomorphine administration.

Apomorphine suppresses TNF-α-induced MMP-9 expression and cell invasion through inhibition of ERK/AP-1 signaling pathway in MCF-7 cells.

Recent studies have shown that dopamine plays an important role in several types of cancer by inhibiting cell growth and invasion via dopamine receptors (DRs), such as dopamine receptor D2. However, the roles of DR agonists in cancer cell growth and invasion remain unclear. In our study, we found that apomorphine (APO), one of the most commonly prescribed DR agonists, inhibited TNF-α-induced matrix metalloprotease-9 (MMP-9) expression and cell invasion in MCF-7 human breast carcinoma cells through DR-independent pathways. Further mechanistic studies demonstrated that APO suppresses TNF-α-induced transcription of MMP-9 by inhibiting activator protein-1 (AP-1), a well-described transcription factor. This is achieved via extracellular signal-regulated kinases 1 and 2 (ERK1/2). Our study has demonstrated that APO targets human MMP-9 in a DR-independent fashion in MCF-7 cells, suggesting that APO is a potential anticancer agent that can suppress the metastatic progression of cancer cells.

Investigation of the inhibitory mechanism of apomorphine against MDM2-p53 interaction.

Mirror-image screening using d-proteins is a powerful approach to provide mirror-image structures of chiral natural products for drug screening. During the course of our screening study for novel MDM2-p53 interaction inhibitors, we identified that NPD6878 (R-(-)-apomorphine) inhibited both the native l-MDM2-l-p53 interaction and the mirror-image d-MDM2-d-p53 interaction at equipotent doses. In addition, both enantiomers of apomorphine showed potent inhibitory activity against the native MDM2-p53 interaction. In this study, we investigated the inhibitory mechanism of both enantiomers of apomorphine against the MDM2-p53 interaction. Achiral oxoapomorphine, which was converted from chiral apomorphines under aerobic conditions, served as the reactive species to form a covalent bond at Cys77 of MDM2, leading to the inhibitory effect against the binding to p53.

The role of beta-arrestin2 in shaping fMRI BOLD responses to dopaminergic stimulation.

RATIONALE: The dopamine D2 receptor (D2R) couples to inhibitory Gi/o proteins and is targeted by antipsychotic and antiparkinsonian drugs. Beta-arrestin2 binds to the intracellular regions of the agonist-occupied D2R to terminate G protein activation and promote internalization, but also to initiate downstream signaling cascades which have been implicated in psychosis. Functional magnetic resonance imaging (fMRI) has proven valuable for measuring dopamine receptor-mediated changes in neuronal activity, and might enable beta-arrestin2 function to be studied in vivo. OBJECTIVES: The present study examined fMRI blood oxygenation level dependent (BOLD) signal changes elicited by a dopamine agonist in wild-type (WT) and beta-arrestin2 knockout (KO) mice, to investigate whether genetic deletion of beta-arrestin2 prolongs or otherwise modifies D2R-dependent responses. METHODS: fMRI BOLD data were acquired on a 9.4 T system. During scans, animals received 0.2 mg/kg apomorphine, i.v. In a subset of experiments, animals were pretreated with 2 mg/kg of the D2R antagonist, eticlopride. RESULTS: Following apomorphine administration, BOLD signal decreases were observed in caudate/putamen of WT and KO animals. The time course of response decay in caudate/putamen was significantly slower in KO vs. WT animals. In cingulate cortex, an initial BOLD signal decrease was followed by a positive response component in WT but not in KO animals. Eticlopride pretreatment significantly reduced apomorphine-induced BOLD signal changes. CONCLUSIONS: The prolonged striatal response decay rates in KO animals might reflect impaired D2R desensitization, consistent with the known function of beta-arrestin2. Furthermore, the apomorphine-induced positive response component in cingulate cortex may depend on beta-arrestin2 signaling downstream of D2R.

Oxoisoaporphine alkaloid derivative 8-1 reduces Aß1-42 secretion and toxicity in human cell and Caenorhabditis elegans models of Alzheimer's disease.

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease and a growing health problem worldwide. Because the drugs currently used to treat AD have certain drawbacks such as single targeting, there is a need to develop novel multi-target compounds, among which oxoisoaporphine alkaloid derivatives are promising candidates. In this study, the possible anti-AD activities of 14 novel oxoisoaporphine alkaloid derivatives that we synthesized were screened and evaluated. We found that, in the 14 novel derivatives, compound 8-1 significantly reduced Aß1-42 secretion in SH-SY5Y cells overexpressing the Swedish mutant form of human ß-amyloid precursor protein (APPsw). Next, we found that compound 8-1 could down-regulate the expression level of ß-amyloid precursor protein (APP) in APPsw cells. Moreover, compound 8-1 significantly delayed paralysis in the Aß1-42-transgenic Caenorhabditis elegans strain GMC101, which could be explained by the fact that compound 8-1 down-regulated acetylcholinesterase activity, protected against H2O2-induced acute oxidative stress and paraquat-induced chronic oxidative stress, and enhanced autophagy activity. Taken together, our data suggest that compound 8-1 could attenuate the onset and development of AD.

Apomorphine - pharmacological properties and clinical trials in Parkinson's disease.

Apomorphine is often considered an archetypal dopamine agonist used in the treatment of Parkinson's disease (PD). However, it can be clearly differentiated from most other commonly used dopamine agonists on the basis of its pharmacology and on its unique clinical profile. Like levodopa and dopamine, apomorphine acts as a potent, direct and broad spectrum dopamine agonist activating all dopamine receptor subtypes. It also has affinity for serotonin receptors, and α-adrenergic receptors. Apomorphine is usually titrated to a dose that provides an equivalent antiparkinsonian response to that provided by levodopa, and its subcutaneous delivery allows a rapid onset of action, usually within 7-10 min. The mode of apomorphine delivery impacts on its clinical profile so as to provide two very different approaches to therapy in PD. When administered as an acute subcutaneous injection, it induces reliable and rapid relief from OFF periods underscoring its utility as a rescue medication. When given as a subcutaneous infusion, it significantly improves overall daily OFF time and there is also evidence to suggest that, in those patients who replace most or all of their oral drugs with apomorphine infusion, dyskinesia may also improve. In this paper, we review the rich pharmacology of apomorphine and review its efficacy in PD based on data from clinical trials.

Stability of apomorphine in solutions containing selected antioxidant agents.

Apomorphine in solution undergoes rapid autoxidation, producing greenish colored solutions, making it difficult to formulate as a stable pharmaceutical solution. To identify the optimum antioxidant agent/combination for apomorphine solution, a high performance liquid chromatography assay was used to study the stability of 50 µg/mL apomorphine HCI in 0.1% L-ascorbic acid (AA), 0.1% sodium metabisulfite (SMB), 0.1% EDTA, and in selected combinations at 25°C, 32°C, and 37°C over a period of 14 days. The stability of apomorphine HCl (10 mg/mL) in 0.1% AA solution and in 0.1% EDTA solution at 25°C and 37°C was also evaluated. Apomorphine HCI solution (50 µg/mL) in 0.1% AA plus 0.1% SMB solution retained 99.7% (at 25°C) and 95.9% (at 37°C) of the initial concentration, as 0.1% AA plus SMB solution minimized the reactive oxygen content in solution which, in turn, reduced the oxidation rate of apomorphine HCl, and there was no green coloration perceptible. Conversely, apomorphine HCl solution (50 µg/mL) in 0.1% SMB solution was unstable as only 0.53% (at 25°C) and 0.06% (at 37°C) of the initial concentration was retained after 14 days. All 10 mg/mL apomorphine HCl samples were stable in both studies. The initial concentration of apomorphine HCl solution markedly affected its rate of oxidation and discoloration. The addition of 0.1% AA to a current formulation of apomorphine HCl injection (Apomine®), which contains SMB as an antioxidant, was recommended as providing the most stable solution.

In vivo evaluation of lipid-based formulations for oral delivery of apomorphine and its diester prodrugs.

In the present study, the differences in oral absorption of apomorphine and its diester prodrugs and the effect of lipid-based formulations on the absorption of apomorphine or its prodrugs were investigated. Apomorphine, dilauroyl apomorphine (DLA) and dipalmitoyl apomorphine (DPA) were orally administered (0.24mmol/kg) to rats as: DLA-o/w emulsion, DPA-o/w emulsion, apomorphine-o/w emulsion, apomorphine aqueous suspension, DLA-Maisine, DLA-soybean oil, DLA-self-emulsifying drug delivery systems (SEDDS), and DLA-w/o emulsion. The o/w and w/o emulsion consisted of Maisine 35-1 emulsified with water in 1:3 and 4:1 ratio, respectively. Tmax of diesters was significantly increased (p≤0.05) compared to apomorphine in o/w emulsion, suggesting that esterification yielded prolonged drug absorption. Cmax, AUC and the relative bioavailability of apomorphine after DLA-SEDDS administration was higher (p≤0.05) than after DLA-w/o administration, indicating that triglycerides and surfactants improved the oral absorption of DLA. Similarly, Cmax and AUC after dosing apomorphine-o/w were significantly higher (p≤0.05) than that of aqueous suspension. This suggested that lipids and lipolysis products possibly aided apomorphine micellar solubilization in intestinal fluids. A combination of prodrug strategy and lipid-based formulations facilitated a higher and prolonged absorption of apomorphine from its diester prodrugs.

Preactivated thiomers for intranasal delivery of apomorphine: In vitro and in vivo evaluation.

The purpose of this study was to synthesize preactivated thiomers with different degrees of preactivation and to evaluate their potential as novel excipient for nasal apomorphine administration. The thiomer (PAA-cys) was synthesized by addition of thiol groups on poly(acrylic acid) with various molecular mass including 100, 250and450kDafollowed by immobilization of 2-mercaptonicotinic acid (2MNA) to thiol groups by disulfide bond formation resulting in PAA-cys-2MNA. These thiomers (PAA100-cys, PAA250-cys and PAA450-cys) were in the next step preactivated by 56.3, 59.5 and 46.5% (medium degree), and 80.1, 81.6 and 87% (high degree), respectively. Apomorphine permeation across porcine nasal mucosa in the presence of PAA100-cys-2MNA, PAA250-cys-2MNA and PAA450-cys-2MNA with high degree of preactivation was 3.1-, 4.4- and 4.1-fold, while 2.7-, 3.4- and 3.0-fold higher than control for medium degree of preactivation, respectively. Administration of apomorphine in the presence of PAA250-cys-2MNA showed in rats 9 and ∼2-fold improvement of relative bioavailability compared with oral and intranasal administration of apomorphine solution, respectively. Because of the pronounced improvement among other polymers, PAA250-cys-2MNA with high degree of preactivation could be considered as promising excipient for nasal delivery of apomorphine.

Determination of apomorphine freebase in sublingual tablets by proton nuclear magnetic resonance spectroscopy.

An apomorphine sublingual tablet formulation under development contains mixtures of apomorphine freebase (FB) and apomorphine hydrochloride salt. It is important to have a reliable analytical method to determine the ratio of the base and salt forms to ensure accuracy, reproducibility and robustness of the manufacturing processes as well as to meet the requirements of the quality target product profile. A Proton Nuclear Magnetic Resonance ((1)H NMR) spectroscopy method based on the proton shift of the amine methyl group (N-CH3) in apomorphine has been developed to determine the mole percentage of freebase to the total mole of freebase and hydrochloride salt in the drug product. The method was evaluated in terms of specificity, linearity, and variability. The presence of excipients does not interfere with the analysis. A standard calibration curve of the chemical shift as a function of the proportion of freebase forms of apomorphine was established, covering the range of 100% apomorphine freebase to 100% apomorhine hydrochloride. The correlation coefficient (r(2)), slope, and Y-intercept of the regression line are 0.998, -0.00596, and 3.191, respectively. The day-to-day variability of the (1)H shift in two instruments in the standard is less than 1% RSD. Three lots of the sublingual tablet drug product were examined and quantified by the standard. The mole percent apomorphine freebase was determined to be 73.8%, 75.2%, and 76.2%, respectively, within 100.0%±2.0% of the target value of 75.0%. The method is a new avenue to use the (1)H NMR technique for determination of apomorphine freebase and salt ratio in a solid drug product dosage form for release testing and in-process control.

Apomorphine and its esters: Differences in Caco-2 cell permeability and chylomicron affinity.

Oral delivery of apomorphine via prodrug principle may be a potential treatment for Parkinson's disease. The purpose of this study was to investigate the transport and stability of apomorphine and its esters across Caco-2 cell monolayer and their affinity towards chylomicrons. Apomorphine, monolauroyl apomorphine (MLA) and dilauroyl apomorphine (DLA) were subjected to apical to basolateral (A-B) and basolateral to apical (B-A) transport across Caco-2 cell monolayer. The stability of these compounds was also assessed by incubation at intestinal pH and physiological pH with and without Caco-2 cells. Molecular dynamics (MD) simulations were performed to understand the stability of the esters on a molecular level. The affinity of the compounds towards plasma derived chylomicrons was assessed. The A-B transport of intact DLA was about 150 times lower than the transport of apomorphine. In contrast, MLA was highly unstable in the aqueous media leading to apomorphine appearance basolaterally. MD simulations possibly explained the differences in hydrolysis susceptibilities of DLA and MLA. The affinity of apomorphine diesters towards plasma derived chylomicrons provided an understanding of their potential lymphatic transport. The intact DLA transport is not favorable; therefore, the conversion of DLA to MLA is an important step for intestinal apomorphine absorption.

Conformational analysis and geometry optimization of apomorphine as an Anti-parkinsonian agen.

Apomorphine, a dopamine D1/D2agonist, is an important drug of choice for the treatment of Parkinson's and related disorders. The present study was designed to perform the conformational analysis and geometry optimization of apomorphine. Resultant optimized structure corresponds to a substance as it is found in nature. This could be used for a variety of experimental and theoretical investigations especially in the field of pharmacokinetics. The results indicate that the best conformation of the molecule is present at minimum potential energy -88702.9595 kcal/mol. At this point molecule will be more active as histamine H1 receptor agonist.

Variación secular de los nacimientos, peso y longitud al nacer: perspectiva local / Secular variation of births, weight and length at birth: Local perspective

Objetivo: Analizar la evolución de los nacimientos y medidas antropométricas al nacer entre 1974-2011 en el Hospital de Limache, Región de Valparaíso, Chile. Pacientes y métodos: Se construyeron series de tiempo de nacimientos, peso y longitud al nacer, peso y talla baja al nacer. Se modelaron las tendencias con regresiones multivariadas usándose splines para representar los cambios de tendencia por década. Resultados: La serie comprende 17.574 nacimientos. Hubo un aumento de los nacimientos/año en los 70 (30/año) y disminución de 17 y 22 nacimientos/año en los 80 y 90 (p < 0,001); después, sin tendencia significativa. Los recién nacidos entre 2000-2011 registran 266 g más que los de la década de los 70 (p < 0,001), alcanzando actualmente en promedio 3.530 g. El bajo peso al nacer disminuyó de 8% en los 70 a 1,1% después de 2000. La longitud al nacer incrementó 1 cm en 37 años, con disminución de la talla baja de 7,6% a 2,1% en el periodo estudiado. Conclusión: Los nacimientos en el Hospital de Limache disminuyeron y las medidas antropométricas al nacer mejoraron; sin embargo, hay que considerar los posibles sesgos que distorsionan estas estimaciones.

Objective: To analyse the outcomes of births and anthropometric measurements at birth of children born between 1974 and 2011 at Limache Hospital (Valparaíso, Chile). Patients and method: Times series were constructed of births, weight and length at birth, and low weight and length at birth. The trend was modelled with linear and logistical regressions using splines to represent breaks in the trend by decade. Results: The series includes 17,574 births. There was an increase in births per year in the 1970s (30/year) and declines in them to 17 and 22 births/year in the 1980s and 1990s, respectively (P < .001), with no significant trend thereafter. Newborns from 2000 to 2011 weighed 266 grams more than those in the 1970s (P < .001), and have now reached a mean weight of 3,530 g. Low birthweight fell from 8% in the 1970s to 1.1% after 2000. Birth length increased by 1 cm in the 37 years studied, with a reduction of low birth length from 7.6% to 2.1% during the period. Conclusion: Live births in the Limache Hospital declined, and anthropometric measurements at birth improved in the years analysed. This information is useful in developing interventions, taking into account the possible selection biases that could distort these estimates and their interpretation.

Apomorphine hydrochloride for the treatment of Parkinson's disease.

Apomorphine (APO) is a potent D1 and D2 dopamine agonist. Plasma maximal concentration is reached in 8-16 min with a plasma half-life of 34-70 min. Bioavailability is close to 100%. It has a rapid antiparkinsonian action after subcutaneous (s.c.) administration with a size effect comparable with that of levodopa. Trials of s.c., oral, sublingual, intravenous, rectal, intranasal and iontophoretic transdermal administration of APO have been attempted in Parkinson's disease (PD), each of these routes have shown some potential for clinical effectiveness but the majority of studies indicate that APO intermittent s.c. administration, on which this review is mainly focused, is an effective therapy for the management of motor symptoms in PD, particularly in advanced phases mainly characterized by motor fluctuations, such as wearing OFF and unpredictable "off". Data on the effect of APO on non-motor symptoms in PD patients are limited but there is strong suggestion of a beneficial effect that warrants further investigation.