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Dopaminergic Agonists (dopaminergic + agonist)
Selected AbstractsAddiction to apomorphine: a clinical case-centred discussionADDICTION, Issue 11 2006Carlos Téllez ABSTRACT Aim To report the case of a patient, who in the context of an anti-Parkinsonian therapy, developed addiction to apomorphine. Methods Clinical case description. Results Apomorphine is a dopaminergic agonist that acts directly on D2 receptors. It has been used in alcoholism, male sexual dysfunction and with diagnostic and therapeutic purposes in Parkinson's disease (PD). Conclusions The present work describes the case of a woman with PD who developed a loss of control over the consumption of apomorphine that resulted in a significant impairment of her functioning. PD patients with high frequency develop different psychiatric symptoms. Conversely, anti-Parkinsonian drugs also generate psychiatric symptoms that can be experienced by the patient as pleasant sensations (,alerting', ,awakening', ,activating', hypomania and hypersexuality). In spite of this, addiction to these drugs in patients with PD is a very rare phenomenon. Currently, the prescription of apomorphine has been extended to patients with erectile dysfunction, which may increase the prevalence of addiction cases or of severe psychiatric symptoms. [source] Postural stability of Parkinson's disease patients is improved by decreasing rigidityEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2005A. Bartoli Postural instability has a big impact on the quality of life of patients with Parkinson's disease (PD) as it often leads to an insecure stance and fall. We investigated if postural stability in these patients improves by decreasing rigidity with a dopaminergic agonist. In our study, we tested eight PD patients with no concomitant diseases. Their age was 61 ± 2 years (mean ± SE) and their Hoehn-Yahr score was 3 ± 0.1. The patients were evaluated according to the Unified Parkinson's Disease Rating Scale for motor function (mUPDRS) and with stabilometric measurements of forward,backward and side-to-side body oscillations during free stance with eyes open. Both evaluations were performed in an ,off' state and in an apomorphine-induced ,on' state. As expected, the mUPDRS score was significantly decreased in the ,on' state with posture being improved in six patients, gait in eight patients and postural stability in seven of eight patients. In addition, apomorphine caused a significant reduction of the relative amplitude of lower frequencies and an increase of the relative amplitude of higher frequencies of forward,backward body oscillations. The results of stabilometry and mUPDRS evaluations are in agreement with the effect of apomorphine on rigidity, indicating that postural stability of PD patients is improved by decreasing rigidity. [source] Pergolide mesylate can improve sexual dysfunction in patients with Parkinson's disease: the results of an open, prospective, 6-month follow-upEUROPEAN JOURNAL OF NEUROLOGY, Issue 7 2004M. Pohanka One of the most disabling problems in males suffering from advanced Parkinson's disease (PD) is complex sexual dysfunction. The effect of dopamine replacement or dopaminergic stimulation on sexual dysfunction has been recently examined and described in patients treated by L-DOPA or apomorphine. Pergolide mesylate is another dopamine agonist with a known high affinity to hD(2S) subtype and a lower affinity to hD(2L) subtype of D2 dopaminergic receptors. It has been repeatedly shown to be a highly effective treatment of the complicated and advanced stages of PD. The current study has been designed to assess its efficacy in the treatment of sexual dysfunction, which frequently accompanies the complicated stage of PD in males. Fourteen male patients suffering from PD, each of whom had been treated with L-DOPA, and in whom additional treatment with peroral dopaminergic agonist (DA) was needed, were followed for a 6-month period. Pergolide mesylate (Permax) was given to each patient, and titrated to a total daily dose of 3 mg. All of the patients were taking L-DOPA. The assessments performed before the start of pergolide treatment consisted of a neurological examination, including Unified Parkinson's Disease Rating Scale (UPDRS) III and IV subscales scoring, Mini Mental State Examination (MMSE) scoring, the neuropsychological examination including Zung scale scoring to exclude depression, biochemical and haematological examinations including the examination of prolactine serum levels; and a sexological examination during which the patients filled-in the International Index of Erectile Function (IIEF) questionnaire. These examinations were repeated during the control assessments at months 1, 3 and 6. To compare the examination results, anova, Friedmann's anova (non-parametric) and Tukey post hoc tests were used. There were statistically significant differences between the values of UPDRS III motor subscale, UPDRS IV (complications of therapy) subscale and all subscales of IIEF when months 0 and 1 were compared with the results obtained at months 3 and 6. The differences between months 0 and 1 and months 3 and 6 (in these items) were virtually insignificant. In conclusion, pergolide substantially improved sexual function in the younger male patients who were still interested in sexual activities. In such cases, the introduction of pergolide might be a better choice than treatment with sildenafile, which usually meets several contraindications in common PD male population. [source] Effects of long-term treatment with dopamine receptor agonists and antagonists on terminal arbor sizeEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2002C. L. Parish Abstract This study demonstrates that pharmacological manipulation of the dopamine (DA) receptors can modulate the size of the axonal tree of substantia nigra pars compacta (SNpc) neurons in mice. Pharmacological blockade or genetic ablation of the D2 receptor (D2R) resulted in sprouting of DA SNpc neurons whereas treatment with a D2 agonist resulted in pruning of the terminal arbor of these neurons. Agents such as cocaine, that indirectly stimulate D2R, also resulted in reduced terminal arbor. Specific D1 agonists or antagonists had no effect on the density of DA terminals in the striatum. We conclude that the D2 receptor has a central role in regulating the size of the terminal arbor of nigrostriatal neurons. These findings have implications relating to the use of dopaminergic agonists in the management of Parkinson's disease and in controlling plasticity following injury, loss or transplantation of DA neurons. [source] Dopaminergic signalling in the rodent neonatal suprachiasmatic nucleus identifies a role for protein kinase A and mitogen-activated protein kinase in circadian entrainmentEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2002Irina L. Schurov Abstract The circadian clock of the suprachiasmatic nuclei (SCN) of perinatal rodents is entrained by maternally derived cues. The SCN of neonatal Syrian hamsters express high-affinity D1 dopamine receptors, and the circadian activity,rest cycle of pups can be entrained by maternal injection of dopaminergic agonists. The present study sought to characterize the intracellular pathways mediating dopaminergic signalling in neonatal rodent SCN. Both dopamine and the D1 agonist SKF81297 caused a dose-dependent increase in phosphorylation of the transcriptional regulator Ca2+/cyclic AMP response element (CRE) binding protein (CREB) in suprachiasmatic GABA-immunoreactive (-IR) neurons held in primary culture. The D1 antagonist SCH23390 blocked this effect. Dopaminergic induction of pCREB-IR in GABA-IR neurons was also blocked by a protein kinase A (PKA) inhibitor, 5,24, and by the MAPK inhibitor, PD98059, whereas KN-62, an inhibitor of Ca2+/calmodulin-dependent (CAM) kinase II/IV was ineffective. Treatment with NMDA increased the level of intracellular Ca2+ in the cultured primary SCN neurons in Mg2+ -free medium, but SKF81297 did not. Blockade of CaM kinase II/IV with KN-62 inhibited glutamatergic induction of pCREB-IR in GABA-IR neurons, whereas 5,24 was ineffective, confirming the independent action of Ca2+ - and cAMP-mediated inputs on pCREB. SKF81297 caused an increase in pERK-IR in SCN cells, and this was blocked by 5,24, indicative of activation of MAPK via D1/cAMP. These results demonstrate that dopaminergic signalling in the neonatal SCN is mediated via the D1-dependent activation of PKA and MAPK, and that this is independent of the glutamatergic regulation via Ca2+ and CaM kinase II/IV responsible for entrainment to the light/dark cycle. [source] Coat colour changes associated with cabergoline administration in bitchesJOURNAL OF SMALL ANIMAL PRACTICE, Issue 8 2003C. Gobello Cabergoline or bromocriptine were administered orally to 60 bitches at doses of 5 ,g/kg and 15 ,g/kg daily, respectively, for two to 45 days for the treatment of pseudopregnancy or for oestrus induction. Seven of the dogs which received cabergoline for more than 14 days developed coat colour changes from the second week of administration to the next coat shedding. Of these, fawn-coloured bitches developed a yellowish coat colour while Argentine boar hounds became black spotted, mainly on their extremities. In previous untreated oestrous periods, these bitches had shown no coat colour changes. It is concluded that a colour shift in certain haircoats of particular breeds could be mediated through the inhibition of the secretion of melanocyte-stimulating hormone by the administration of the dopaminergic agonist cabergoline for more than two weeks. Transient coat colour changes should be considered a possible side effect when planning long-term treatment with dopaminergic agonists in dogs. [source] The pharmacological treatment for uremic restless legs syndrome: Evidence-based review,MOVEMENT DISORDERS, Issue 10 2010Márcio Moysés de Oliveira MD Abstract Restless legs syndrome (RLS) is a common and often misdiagnosed entity among the general population and it may be more common among dialysis patients, with an estimated prevalence of 6.6 to 21.5%. The treatment for uremic RLS has been controversial and therefore a systematic synthesis of the evidence is needed in order to evaluate the effectiveness and safety of treatments for uremic RLS. This was a systematic review of randomized or quasi-randomized double-blind trials on treatments for uremic RLS. The outcomes considered were relief of RLS symptoms marked on a validated scale, subjective sleep quality, sleep quality measured using night polysomnography and actigraphy, quality of life measured subjectively, and adverse events associated with these treatments. Six eligible clinical trials were included. The results from subjective analyses in these studies were divergent, although objective analyses in one trial showed that there was a statistically significant improvement in periodic leg movement while asleep in the treatment group. No combined analysis (meta-analysis) was performed. The most common adverse event seen was gastrointestinal symptoms. Only a few therapeutic trials on patients with uremia with RLS have been published, and there is insufficient scientific evidence to favor any specific therapeutic regimen for uremic-associated RLS. Therapy using levodopa, dopaminergic agonists, anticonvulsants, and clonidine tend to be effective, but further studies are needed. © 2010 Movement Disorder Society [source] Methadone for refractory restless legs syndromeMOVEMENT DISORDERS, Issue 3 2005William G. Ondo MD Abstract Most cases of restless legs syndrome (RLS) initially respond well to dopaminergic agonists. However, an unknown percentage of patients is intolerant of dopaminergic adverse events, initially or subsequently refractory, or develops limiting augmentation. We administered methadone 5 to 40 mg/day (final dose, 15.6 ± 7.7) to 29 RLS patients who failed dopaminergics. They were currently taking or had previously tried 5.9 ± 1.7 (range, 3,9) different medications for RLS and 2.9 ± 0.8 (range, 2,4) different dopaminergics. Of the 27 patients who met inclusion criteria, 17 have remained on methadone for 23 ± 12 months (range, 4,44 months) at a dose of 15.5 ± 7.7 mg/day; 2 dialysis RLS patients died while on methadone, and 8 stopped the treatment (5 for adverse events, 2 for lack of efficacy, and 1 for logistical reasons). All patients who remain on methadone report at least a 75% reduction in symptoms, and none have developed augmentation. Methadone should be considered in RLS patients with an unsatisfactory dopaminergic response. © 2004 Movement Disorder Society [source] Narcoleptic canines display periodic leg movements during sleepPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 3 2001Mutsumi Okura MD Abstract Periodic leg movements during sleep (PLMS) is a high prevalent sleep disorder of unknown etiology. The disease is pharmacologically treated with dopaminergic agonists (i.e. D2/D3 agonists) and opiates. Periodic leg movements during sleep often occur in narcoleptic patients. We observed that narcoleptic canines, like narcoleptic humans, also exhibit jerky, unilateral or bilateral slow leg movements during sleep. The movements in dogs are characterized by repetitive dorsiflexions of the ankle, lasting 0.5,1.5 s, and occur at regular intervals of 3,20 s, thus showing similarities to PLMS in humans. The observation that D2/D3 agonists aggravate cataplexy in narcoleptic dogs suggests that altered dopaminergic regulation in canine narcolepsy may play a critical role in both cataplexy and PLMS. Our canines may therefore be an invaluable resource in PLMS research. [source] | ||||||||||