This narrative review reports on the pharmacological and pharmacokinetic properties of rotigotine, a non-ergolinic D
3
/D
2
/D
1
dopamine receptor agonist approved for the treatment of early- and ...advanced-stage Parkinson’s disease (PD) and moderate to severe restless legs syndrome (RLS). Rotigotine is formulated as a transdermal patch providing continuous drug delivery over 24 h, with a plasma concentration profile similar to that of administration via continuous intravenous infusion. Absolute bioavailability after 24 h transdermal delivery is 37 % of the applied rotigotine dose. Following a single administration of rotigotine transdermal system (24-h patch-on period), most of the absorbed drug is eliminated in urine and feces as sulphated and glucuronidated conjugates within 24 h of patch removal. The drug shows a high apparent volume of distribution (>2500 L) and a total body clearance of 300–600 L/h. Rotigotine transdermal system provides dose-proportional pharmacokinetics up to supratherapeutic dose rates of 24 mg/24 h, with steady-state plasma drug concentrations attained within 1–2 days of daily dosing. The pharmacokinetics of rotigotine transdermal patch are similar in healthy subjects, patients with early- or advanced-stage PD, and patients with RLS when comparing dose-normalized area under the plasma concentration–time curve (AUC) and maximum plasma drug concentration (
C
max
), as well as half-life and other pharmacokinetic parameters. Also, it is not influenced in a relevant manner by age, sex, ethnicity, advanced renal insufficiency, or moderate hepatic impairment. No clinically relevant drug–drug interactions were observed following co-administration of rotigotine with levodopa/carbidopa, domperidone, or the CYP450 inhibitors cimetidine or omeprazole. Also, pharmacodynamics and pharmacokinetics of an oral hormonal contraceptive were not influenced by rotigotine co-administration. Rotigotine was generally well tolerated, with an adverse event profile consistent with dopaminergic stimulation and use of a transdermal patch. These observations, combined with the long-term efficacy demonstrated in clinical studies, support the use of rotigotine as a continuous non-ergot D
3
/D
2
/D
1
dopamine receptor agonist in the treatment of PD and RLS.
Tetrabenazine (TBZ) selectively depletes central monoamines by reversibly binding to the type 2 vesicular monoamine transporter. Open-label reports indicate TBZ is effective in treating chorea.
To ...examine the safety, efficacy, and dose tolerability of TBZ for treating chorea in Huntington disease (HD).
The authors randomized 84 ambulatory patients with HD to receive TBZ (n = 54) or placebo (n = 30) for 12 weeks. TBZ was increased over 7 weeks up to a maximum of 100 mg/day or until the desired antichoreic effect occurred or intolerable adverse effects supervened. The primary outcome was the change from baseline in the chorea score of the Unified Huntington's Disease Rating Scale (UHDRS) RESULTS: TBZ treatment resulted in a reduction of 5.0 units in chorea severity compared with a reduction of 1.5 units on placebo treatment (adjusted mean effect size = -3.5 +/- 0.8 UHDRS units mean +/- SE; 95% CI: -5.2, -1.9; p < 0.0001). There was also a significant benefit on ratings of clinical global improvement. There were five study withdrawals in the TBZ group and five serious adverse events (SAEs) in four subjects (drowning suicide, complicated fall, restlessness/suicidal ideation, and breast cancer) compared with one withdrawal and no SAEs in the placebo group.
Tetrabenazine (TBZ), at adjusted dosages of up to 100 mg/day, effectively lessens chorea in ambulatory patients with Huntington disease. TBZ should be dosed individually based on ongoing assessment of possible adverse side effects.
Abstract Long-term administration of l -3,4-dihydroxyphenylalanine (levodopa), the mainstay treatment for Parkinson's disease (PD), is accompanied by fluctuations in its duration of action and motor ...complications (dyskinesia) that dramatically affect the quality of life of patients. Levodopa-induced dyskinesias (LID) can be modeled in rats with unilateral 6-OHDA lesions via chronic administration of levodopa, which causes increasingly severe axial, limb, and orofacial abnormal involuntary movements (AIMs) over time. In previous studies, we showed that the direct activation of CB1 cannabinoid receptors alleviated rat AIMs. Interestingly, elevation of the endocannabinoid anandamide by URB597 (URB), an inhibitor of endocannabinoid catabolism, produced an anti-dyskinetic response that was only partially mediated via CB1 receptors and required the concomitant blockade of transient receptor potential vanilloid type-1 (TRPV1) channels by capsazepine (CPZ) (Morgese et al., 2007). In this study, we showed that the stimulation of peroxisome proliferator-activated receptors (PPAR), a family of transcription factors activated by anandamide, contributes to the anti-dyskinetic effects of URB + CPZ, and that the direct activation of the PPARγ subtype by rosiglitazone (RGZ) alleviates levodopa-induced AIMs in 6-OHDA rats. AIM reduction was associated with an attenuation of levodopa-induced increase of dynorphin, zif-268, and of ERK phosphorylation in the denervated striatum. RGZ treatment did not decrease striatal levodopa and dopamine bioavailability, nor did it affect levodopa anti-parkinsonian activity. Collectively, these data indicate that PPARγ may represent a new pharmacological target for the treatment of LID.
Among the diseases affecting the central nervous system (CNS), neurodegenerations attract the interest of both the clinician and the medicinal chemist. The increasing average age of population, the ...growing number of patients, and the lack of long-term effective remedies push ahead the quest for novel tools against this class of pathologies. We present a review on the state of the art of the molecules (or combination of molecules) of natural origin that are currently under study against two well-defined pathologies: Parkinson’s disease (PD) and Huntington’s disease (HD). Nowadays, very few tools are available for preventing or counteracting the progression of such diseases. Two major parameters were considered for the preparation of this review: particular attention was reserved to these research works presenting well-defined molecular mechanisms for the studied compounds, and where available, papers reporting in vivo data were preferred. A literature search for peer-reviewed articles using PubMed, Scopus, and Reaxys databases was performed, exploiting different keywords and logical operators: 91 papers were considered (preferentially published after 2015). The review presents a brief overview on the etiology of the studied neurodegenerations and the current treatments, followed by a detailed discussion of the natural and semisynthetic compounds dividing them in different paragraphs considering their several mechanisms of action.
Dyskinesias encompass a variety of different hyperkinetic phenomenologies, particularly chorea, dystonia, stereotypies, and akathisia. Levodopa-induced dyskinesia (LID) is one of the main types of ...drug-induced dyskinesia, occurring in patients with Parkinson’s disease (PD) who have been treated with levodopa for long time, but this side effect may be encountered even within a few weeks or months after initiation of levodopa therapy. Based on the temporal pattern in relationship to levodopa dosing, LIDs are divided into “peak-dose dyskinesia,” “diphasic dyskinesia,” and “wearing off” or “off-period” dyskinesia, of which peak-dose dyskinesia is the most common, followed by off-period, and then diphasic dyskinesia. Treatment strategy includes identifying the kind of dyskinesia and tailoring treatment accordingly. Peak-dose dyskinesia is treated mainly by reducing individual doses of levodopa and adding amantadine and dopamine agonists, whereas off-period dystonia often responds to baclofen and botulinum toxin injections. Diphasic dyskinesias, occurring particularly in patients with young-onset PD, are the most difficult to treat. While fractionation of levodopa dosage is the most frequently utilized strategy, many patients require deep brain stimulation to control their troublesome motor fluctuations and LIDs. A variety of emerging (experimental) drugs currently in development promise to provide better control of LIDs and other levodopa-related complications in the near future.
The chronic use and high dosing of typical neuroleptics or centrally acting dopamine receptor blocking antiemetics predispose patients to the onset of tardive syndromes. One particular subtype, ...tardive dyskinesia, is characterized by rapid, repetitive, stereotypic, involuntary movements of the face, limbs or trunk. The inhibition of the vesicular monoamine transporter system, using tetrabenazine therapy, improves the severity of tardive dyskinesia. But there are also drawbacks to tetrabenazine treatment, such as a fluctuating response and the need for frequent intake due to its rapid metabolism. Clinical research on the potentially more efficacious and easier to use tetrabenazine analogs is already under way. One of them is valbenazine, the purified parent drug of the (+)-α-isomer of tetrabenazine. The FDA lowered approval hurdles for valbenazine due to a successful Phase II trial, which showed a distinctive improvement in tardive dyskinesia symptoms during valbenazine administration. This resurgence in the clinical research of tardive syndrome therapy is most welcome. This author notes that the putative long-term side effects of valbenazine should carefully be investigated in the future via naturalistic observational trials. Furthermore, valbenazine may also support the onset of symptoms, such as Parkinsonism and depression, with chronic administration, as it, to a certain extent, shares the mode of action of tetrabenazine.
Previously, controlled trials have demonstrated the efficacy and tolerability of fixed doses of incobotulinumtoxinA (Xeomin, NT 201, botulinum toxin type A free from complexing proteins) to treat ...cervical dystonia (CD). To explore the clinical relevance of these findings, this study evaluated long-term use of flexible dosing regimens of incobotulinumtoxinA in a setting close to real-life clinical practice.
Patients with CD received five injection sessions of incobotulinumtoxinA using flexible intervals (10-24 weeks) and dosing (≤300 Units) based on patients' needs. Outcome measures included Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), the Dystonia Discomfort Scale (DDS), Investigator Global Assessment of Efficacy (IGAE) and Patient Evaluation of Global Response (PEGR).
Of 76 patients enrolled (men: 34%; naïve to botulinum toxin: 25%), 64 completed the study, receiving treatment over a duration of 49.3-114.1 weeks (total maximum duration: 121 weeks). Mean TWSTRS-Total and DDS scores significantly improved from study baseline to 4 weeks after each injection session (ranges of improvement: TWSTRS-Total: -11.7 to -14.3; DDS: -20.2 to -23.0). Up to 81.6% of investigators rated the efficacy as 'good' or 'very good' (IGAE) and up to 78.9% of patients rated the treatment response as 'improved' (PEGR). The most common adverse events were dysphagia, nasopharyngitis and headache.
In this long-term study, incobotulinumtoxinA was administered using more flexible dosing regimens than those permitted in previous controlled trials. Repeated injections of highly purified incobotulinumtoxinA are effective and well tolerated for the treatment of CD in a setting close to real-life clinical practice.
Local chemodenervation with botulinum toxin (BoNT) injections to relax abnormally contracting muscles has been shown to be an effective and well-tolerated treatment in a variety of movement disorders ...and other neurological and non-neurological disorders. Despite almost 30 years of therapeutic use, there are only few studies of patients treated with BoNT injections over long period of time. These published data clearly support the conclusion that BoNT not only provides safe and effective symptomatic relief of dystonia but also long-term benefit and possibly even favorably modifying the natural history of this disease. The adverse events associated with chronic, periodic exposure to BoNT injections are generally minor and self-limiting. With the chronic use of BoNT and an expanding list of therapeutic indications, there is a need to carefully examine the existing data on the long-term efficacy and safety of BoNT. In this review we will highlight some of the aspects of long-term effects of BoNT, including efficacy, safety, and immunogenicity.
L-Dopa in dystonia: A modern perspective Maas, Roderick P.P.W.M; Wassenberg, Tessa; Lin, Jean-Pierre ...
Neurology,
2017-May-09, 2017-05-09, 20170509, Letnik:
88, Številka:
19
Journal Article
Recenzirano
“Every child exhibiting dystonia merits an L-dopa trial, lest the potentially treatable condition of dopa-responsive dystonia (DRD) is missed” has been a commonly cited and highly conserved adage in ...movement disorders literature stemming from the 1980s. We here provide a historical perspective on this statement, discuss the current diagnostic and therapeutic applications of L-dopa in everyday neurologic practice, contrast these with its approved indications, and finish with our view on both a diagnostic and therapeutic trial in children and adults with dystonia. In light of the relatively low prevalence of DRDs, the large interindividual variation in the required L-dopa dose, the uncertainty about an adequate trial duration, the substantial advances in knowledge on etiology and pathophysiology of these disorders, and the availability of various state-of-the-art diagnostic tests, we think that a diagnostic L-dopa trial as a first step in the approach of early-onset dystonia (≤25 years) is outdated. Rather, in high-resource countries, we suggest to use L-dopa after biochemical corroboration of a defect in dopamine biosynthesis, in genetically confirmed DRD, or if nigrostriatal degeneration has been demonstrated by nuclear imaging in adult patients presenting with lower limb dystonia. Furthermore, our literature study on the effect of a therapeutic trial to gain symptomatic relief revealed that L-dopa has occasionally proven beneficial in several established “non-DRDs” and may therefore be considered in selected cases of dystonia due to other causes. In summary, we argue against the application of L-dopa in every patient with early-onset dystonia and support a more rational therapeutic use.
PDF
