Reassessment of amphetamine- and phencyclidine-induced locomotor hyperactivity as a model of psychosis-like behavior in rats.

Locomotor hyperactivity induced by psychotomimetic drugs, such as amphetamine and phencyclidine, is widely used as an animal model of psychosis-like behaviour and is commonly attributed to an interaction with dopamine release and N-methyl-D-aspartate (NMDA) receptors, respectively. However, what is often not sufficiently taken into account is that the pharmacological profile of these drugs is complex and may involve other neurotransmitter/receptor systems. Therefore, this study aimed to assess the effect of three antagonists targeting different monoamine pathways on amphetamine- and phencyclidine-induced locomotor hyperactivity. A total of 32 rats were pre-treated with antagonists affecting dopaminergic, noradrenergic and serotonergic transmission: haloperidol (0.05 mg/kg), prazosin (2 mg/kg) and ritanserin (1 mg/kg), respectively. After 30 min of spontaneous activity, rats were injected with amphetamine (0.5 mg/kg) or phencyclidine (2.5 mg/kg) and distance travelled, stereotypy and rearing recorded in photocell cages over 90 min. Pre-treatment with haloperidol or prazosin both reduced amphetamine-induced hyperactivity although pre-treatment with ritanserin had only a partial effect. None of the pre-treatments significantly altered the hyperlocomotion effects of phencyclidine. These findings suggest that noradrenergic as well as dopaminergic neurotransmission is critical for amphetamine-induced locomotor hyperactivity. Hyperlocomotion effects of phencyclidine are dependent on other factors, most likely NMDA receptor antagonism. These results help to interpret psychotomimetic drug-induced locomotor hyperactivity as an experimental model of psychosis.

Betaine prevents and reverses the behavioral deficits and synaptic dysfunction induced by repeated ketamine exposure in mice.

As an N-methyl-D-aspartate (NMDA) receptor inhibitor, ketamine has become a popular recreational substance and currently is used to address treatment-resistant depression. Since heavy ketamine use is associated with persisting psychosis, cognitive impairments, and neuronal damage, the safety of ketamine treatment for depression should be concerned. The nutrient supplement betaine has been shown to counteract the acute ketamine-induced psychotomimetic effects and cognitive dysfunction through modulating NMDA receptors. This study aimed to determine whether the adjunctive or subsequent betaine treatment would improve the enduring behavioral disturbances and hippocampal synaptic abnormality induced by repeated ketamine exposure. Mice received ketamine twice daily for 14 days, either combined with betaine co-treatment or subsequent betaine post-treatment for 7 days. Thereafter, three-chamber social approach test, reciprocal social interaction, novel location/object recognition test, forced swimming test, and head-twitch response induced by serotonergic hallucinogen were monitored. Data showed that the enduring behavioral abnormalities after repeated ketamine exposure, including disrupted social behaviors, recognition memory impairments, and increased depression-like and hallucinogen-induced head-twitch responses, were remarkably improved by betaine co-treatment or post-treatment. Consistently, betaine protected and reversed the reduced hippocampal synaptic activity, such as decreases in field excitatory post-synaptic potentiation (fEPSP), long-term potentiation (LTP), and PSD-95 levels, after repeated ketamine treatment. These results demonstrated that both co-treatment and post-treatment with betaine could effectively prevent and reverse the adverse behavioral manifestations and hippocampal synaptic plasticity after repeated ketamine use, suggesting that betaine can be used as a novel adjunct therapy with ketamine for treatment-resistant depression and provide benefits for ketamine use disorders.

Pharmacological strategies for the management of comorbid depression and schizophrenia.

Introduction: Depressive symptoms may occur in any phase of schizophrenia and can have far-reaching consequences.Areas covered: The author focuses on recent reviews and meta-analyses dealing with the prevalence, importance, etiopathogenesis, and pharmacotherapy of comorbid depression and schizophrenia. Depressive symptoms in acute episodes may improve in parallel with psychosis due to antipsychotic treatment. Therefore, the first step is to evaluate the current antipsychotic treatment of psychotic symptoms and consider changing the dosage. A second step is switching antipsychotic medications, since there are indications that some medications are slightly more effective in reducing depressive symptoms than others. For persistent depressive episodes, additional therapeutic interventions are indicated. Most guidelines recommend the administration of antidepressants as an add-on treatment with a limited evidence level. Immunotherapeutic strategies could be successful, at least in some schizophrenia patients.Expert opinion: In the near future, precision psychiatry should enable clinicians to recognize specific biotypes with unique biosignatures that will guide accurate and prompt clinical management for individual patients.

[Cannabis use in subjects at ultra high risk for psychosis]. / Usage de Cannabis chez les sujets à ultra-haut risque de psychose.

Cannabis use is widespread among people at ultra-high risk (UHR) for psychosis. The causal link as well as the temporal link between cannabis use and further occurrence of psychosis in UHR people remain inconclusive. Current science data supported an increased risk of transition to psychosis in cannabis users who are genetically predisposed to psychosis. This risk would be even greater in the presence of a family history of psychosis, in case of a strong use and an early onset use. Several models have been cited to explain the link between cannabis use and the subsequent onset of psychosis or prepsychotic states: cannabis-induced modifications of some brain structures, a dysregulation of the hypothalamic-pituitary axis and an alteration of normal neurological development via the endocannabinoid system. Cannabis represents a modifiable risk for psychosis. Current interventions aim to reduce or stop the cannabis use in order to reduce the risk of transition to psychosis.

Antipsychotic-Induced Dopamine Supersensitivity Psychosis: Pharmacology, Criteria, and Therapy.

The first-line treatment for psychotic disorders remains antipsychotic drugs with receptor antagonist properties at D2-like dopamine receptors. However, long-term administration of antipsychotics can upregulate D2 receptors and produce receptor supersensitivity manifested by behavioral supersensitivity to dopamine stimulation in animals, and movement disorders and supersensitivity psychosis (SP) in patients. Antipsychotic-induced SP was first described as the emergence of psychotic symptoms with tardive dyskinesia (TD) and a fall in prolactin levels following drug discontinuation. In the era of first-generation antipsychotics, 4 clinical features characterized drug-induced SP: rapid relapse after drug discontinuation/dose reduction/switch of antipsychotics, tolerance to previously observed therapeutic effects, co-occurring TD, and psychotic exacerbation by life stressors. We review 3 recent studies on the prevalence rates of SP, and the link to treatment resistance and psychotic relapse in the era of second-generation antipsychotics (risperidone, paliperidone, perospirone, and long-acting injectable risperidone, olanzapine, quetiapine, and aripiprazole). These studies show that the prevalence rates of SP remain high in schizophrenia (30%) and higher (70%) in treatment-resistant schizophrenia. We then present neurobehavioral findings on antipsychotic-induced supersensitivity to dopamine from animal studies. Next, we propose criteria for SP, which describe psychotic symptoms and co-occurring movement disorders more precisely. Detection of mild/borderline drug-induced movement disorders permits early recognition of overblockade of D2 receptors, responsible for SP and TD. Finally, we describe 3 antipsychotic withdrawal syndromes, similar to those seen with other CNS drugs, and we propose approaches to treat, potentially prevent, or temporarily manage SP.

Cannabis and Neuropsychiatry, 2: The Longitudinal Risk of Psychosis as an Adverse Outcome.

Psychosis is one of the most serious among the adverse effects associated with cannabis use. The association between cannabis use and psychosis has been variously explored in a series of recent meta-analyses. The results of these meta-analyses show that persons who develop psychosis experience onset of psychosis about 2-3 years earlier if they are cannabis users; this effect is not observed with alcohol or other substance use. Higher levels of cannabis use are associated with greater risk of psychosis. Current cannabis abuse or dependence (but not past use or lower levels of current use) increases the risk of transition into psychosis in persons at ultrahigh risk of psychosis. About a third of patients with first-episode psychosis are cannabis users, and, at follow-up, about half of these users are found to continue their cannabis use. Continued cannabis use (in those who are treated after developing psychosis) is associated with higher risk of relapse into psychosis, and discontinuation of cannabis use reduces the risk of relapse to that in cannabis nonusers. Finally, persons with psychosis who continue to use cannabis have more severe positive symptoms and poorer levels of functioning. Because experimental studies in humans show that cannabinoids and cannabis can induce psychotic symptoms, it is reasonable to assume that the epidemiologic data indicate a causal effect of cannabis in anticipating, triggering, or exacerbating psychosis in vulnerable individuals and in worsening the course and outcome of the illness in those who continue to use the substance. Given the public health implications of these findings, the trend to legalize medical marijuana must be viewed with concern, and efforts are necessary to educate patients and the public about the serious mental and physical health risks associated with cannabis use and abuse.

[MEDICAL CANNABIS].

The cannabis plant has been known to humanity for centuries as a remedy for pain, diarrhea and inflammation. Current research is inspecting the use of cannabis for many diseases, including multiple sclerosis, epilepsy, dystonia, and chronic pain. In inflammatory conditions cannabinoids improve pain in rheumatoid arthritis and:pain and diarrhea in Crohn's disease. Despite their therapeutic potential, cannabinoids are not free of side effects including psychosis, anxiety, paranoia, dependence and abuse. Controlled clinical studies investigating the therapeutic potential of cannabis are few and small, whereas pressure for expanding cannabis use is increasing. Currently, as long as cannabis is classified as an illicit drug and until further controlled studies are performed, the use of medical cannabis should be limited to patients who failed conventional better established treatment.

[Post-partum psychosis: an acute illness requiring resolute action]. / Post-partumpsychose: een acuut beeld dat doortastend optreden vergt.

A 34-year-old woman was seen in our hospital, where she had been brought after jumping from the window together with her 3-month-old son. She had survived the jump with severe foot fractures, but her son had died. In the weeks after giving birth she had suffered from sleep disturbances and fluctuating affective symptoms. After initial response to benzodiazepines, she developed psychotic symptoms that lead her to jump from the window. Psychotic symptoms had developed within just 3 days, and medical action came too late. Here we urge clinicians to be alert to psychotic symptoms in the first months of maternity, and to instantly refer young mothers with these symptoms to a closed ward for adequate treatment. Treatment starts with benzodiazepines to restore sleep, followed by an antipsychotic agent if symptoms fail to improve with this treatment; if psychosis and affective symptoms do not improve after 2 weeks this regimen should be followed by lithium augmentation.

Inhibition of apomorphine-induced behavioral sensitization in rats pretreated with fluoxetine.

Despite a number of clinically useful effects, there is growing evidence that psychosis and impulse control disorders develop in patients on apomorphine therapy. Evidence suggests a critical role of serotonin-1A receptors in psychosis, drug abuse, and in the mechanism of action of the prototypical selective serotonin reuptake inhibitor fluoxetine. We investigated whether fluoxetine can prevent apomorphine-induced behavioral sensitization in a rat model of psychosis. Animals treated with fluoxetine (5 and 10 mg/kg) for 2 weeks were subsequently cotreated with apomorphine (1.0 mg/kg) for 7 days. A single injection of apomorphine increased motor activity, whereas repeated daily injections produced a progressive sensitization of motor behavior. The sensitization effects of apomorphine did not occur in fluoxetine-pretreated and subsequently cotreated animals. To further elucidate the mechanism involved in the inhibition of apomorphine sensitization in fluoxetine-treated animals, we found that apomorphine-induced motor behavior was much greater in repeated apomorphine-treated than repeated saline-treated animals. It was also greater in apomorphine and fluoxetine-cotreated animals, but not in animals pretreated and cotreated with fluoxetine. The mechanism involved in the inhibition of apomorphine sensitization in fluoxetine-pretreated animals is discussed. The findings introduce an innovative approach for extending the therapeutic use of apomorphine and classical psychostimulant drugs.

[Acute psychosis as a side effect of efavirenz therapy with metabolic anomalies: an important differential diagnosis of HIV-associated psychoses]. / Akute Psychose als Nebenwirkung der Therapie mit Efavirenz bei metabolischer Anomalie : Eine wichtige Differenzialdiagnose HIV-assoziierter Psychosen.

Among patients with human immunodeficiency virus (HIV) infections psychiatric disease poses a particular challenge for caregivers. Neuropsychiatric side effects of efavirenz have been described in up to 40% of patients showing dizziness, insomnia, unusual dreams, mood instability, personality alterations and thought disorders. In immigrants from Africa and South America these side effects may be related to elevated plasma concentrations of efavirenz due to polymorphisms of cytochrome P450 isozymes (especially G516T). Alleles for these polymorphisms are more frequent in African and South American patients. We report a case of a 52-year-old patient from Guinea who was referred to the department of neurology under the diagnosis of HIV-associated neurocognitive disorder (HAND). Since the start of combined antiretroviral therapy (cART) including efavirenz the patient had suffered severe personality alterations, acoustic and visual hallucinations and delusions which led to discrimination and reduced quality of life. Diagnostic procedures including magnetic resonance imaging (MRT) and spinal fluid analysis resulted in normal values and did not explain the disease. After switching to nevirapin instead of efavirenz the psychotic symptoms disappeared within 5 days.

[Challenges in the pharmacotherapeutic management of the hospitalised patient with Parkinson's disease]. / Desafíos en el manejo farmacoterapéutico del paciente ingresado con enfermedad de Parkinson.

Patients with Parkinson's disease (PD) are admitted to hospital more frequently and for a longer time than other patients from the same age group. The reason they are hospitalised is often different from their underlying baseline disease and they are usually attended in services with little knowledge of the disease. Both the errors made when administering levodopa and the inappropriate use of pharmacological agents with a central antidopaminergic action are relatively common during their stay in hospital. This study reports on an analysis of the literature available on the challenges and complications that patients with PD have to deal with when they are admitted to hospital, especially those that have to do with pharmacotherapy. Likewise, the authors also propose a series of strategies that lead to better care of the patients during the time they are in hospital, including aspects such as controlling the supplies of antiparkinsonian medication and establishing protocols for the therapeutic exchange of antiparkinsonian agents, as well as protocols for a suitable management of comorbidities in this kind of patients. Other strategies involve encouraging self-management of the antiparkinsonian treatment by the hospitalised patients, conducting follow-up studies to monitor inappropriate prescriptions or creating the figure of 'specialist in PD'. To do so, it will be necessary to raise the awareness of the healthcare staff at the hospital, as well as that of both patients and their relatives, about the problems derived from an inappropriate management of pharmacotherapy in PD.

TITLE: Desafios en el manejo farmacoterapeutico del paciente ingresado con enfermedad de Parkinson.Los pacientes con enfermedad de Parkinson (EP) ingresan en el hospital con mayor frecuencia y durante mas tiempo que los pacientes del mismo grupo etario. El motivo del ingreso es a menudo diferente de su enfermedad de base, y son habitualmente atendidos en servicios con un conocimiento pobre de la enfermedad. Tanto los errores en el momento de la administracion de levodopa como el uso inapropiado de farmacos con accion antidopaminergica central son relativamente comunes durante su estancia hospitalaria. En este estudio se lleva a cabo un analisis de la bibliografia disponible sobre los desafios y las complicaciones a los que se enfrentan los pacientes con EP cuando ingresan en el hospital, principalmente en aquellos relacionados con la farmacoterapia. Asimismo, se proponen una serie de estrategias que redunden en una atencion a los pacientes durante su ingreso hospitalario, que incluyen aspectos como el control de las existencias de medicamentos antiparkinsonianos y el establecimiento de protocolos de intercambio terapeutico de antiparkinsonianos, asi como de protocolos para el manejo adecuado de comorbilidades en este tipo de pacientes; el fomento de la autogestion del tratamiento antiparkinsoniano por parte de los pacientes ingresados; la realizacion de estudios de seguimiento de prescripciones inapropiadas o la creacion de la figura de 'especialista en EP'. Para ello sera necesario impulsar la concienciacion del personal sanitario del hospital, asi como de los pacientes y sus familiares, sobre los problemas derivados del manejo inapropiado de la farmacoterapia en EP.

CB2 receptor agonism reverses MK-801-induced disruptions of prepulse inhibition in mice.

RATIONALE: Whilst cannabinoid CB2 receptors were thought to exist predominantly in immune cells in the periphery, the recent discovery of CB2 receptors in the brain has led to an increased interest in the role of these central CB2 receptors. Several studies have reported an association with CB2 receptors and schizophrenia. Sensorimotor gating deficits occur in schizophrenia patients and can be induced in animals using psychotomimetic drugs such as N-methyl-D-aspartate (NMDA) receptor antagonists. OBJECTIVES: The aim of this study was to investigate the effect of CB2 ligands on sensorimotor gating, either alone, or on sensorimotor gating deficits induced by the NMDA receptor antagonist MK-801 in mice. METHOD: The effects of CB2 receptor ligands on prepulse inhibition (PPI), an operational measure of sensorimotor gating, alone or when administrated in combination with MK-801, in Balb-C mice were evaluated. RESULTS: The CB2 receptor agonist JWH015 had no significant effect on PPI alone but reversed disruptions in PPI induced by MK-801. This effect was blocked by co-administration of the CB2 receptor antagonist AM630, but not by co-administration of the CB1 receptor antagonist AM251, indicating a CB2-mediated effect. The mixed CB1/CB2 receptor agonist JWH203 was partially able to reverse MK-801-induced PPI disruptions. Neither the CB2 receptor antagonist AM630 nor the CB1 receptor antagonist AM251 had any significant effect alone or on MK-801-induced disruptions in PPI. CONCLUSIONS: CB2 receptor agonism reversed MK-801 disruptions in sensorimotor gating deficits in mice, indicating that CB2 agonism may have a protective effect against aspects of drug-induced psychosis.

Strategies to prevent the neuropsychiatric side-effects of corticosteroids: a case report and review of the literature.

PURPOSE OF REVIEW: The use of corticosteroids is increasing, and while the physical complications of their use are well known, the neuropsychiatric consequences are not. This review focuses on preventing these neuropsychiatric complications. Although there are limited data on this subject, it is a problem that clinicians face on a regular basis. RECENT FINDINGS: The incidence of neuropsychiatric complications rises rapidly once the daily dose of prednisone is greater than 40 mg. Other risk factors for neuropsychiatric symptoms are damaged blood-brain barrier and hypoalbuminemia. All patients receiving corticosteroids and their caregivers should be warned about the potential neuropsychiatric complications. Small trials have supported the use of various agents as prophylaxis. The development of neuropsychiatric symptoms secondary to corticosteroids should lead to prompt involvement of liaison psychiatry. SUMMARY: There is a lack of large randomized controlled studies to inform clinical practice. At present, lithium and olanzapine probably represent the best choices for prophylaxis. Patients with a prior history of steroid-related psychosis or mania should be considered for prophylaxis when future courses of steroids are prescribed as limited data, and our clinical experience suggests that this can reduce the future episodes of neuropsychiatric side-effects.

Withdrawal symptoms and rebound syndromes associated with switching and discontinuing atypical antipsychotics: theoretical background and practical recommendations.

With the widespread use of atypical or second-generation antipsychotics, switching treatment has become current practice and more complicated, as the pharmacological profiles of these agents differ substantially despite their similarity in being 'atypical'. All share the ability to block dopamine D2 receptors, and most of them also block serotonin 5-HT2A receptors. Apart from these common features, some atypical antipsychotics are also able to block or stimulate other dopamine or serotonin receptors, as well as histaminergic, muscarinergic or adrenergic receptors. As a result of the varying receptor affinities, in switching or discontinuing compounds several possible pitfalls have to be considered, including the occurrence of withdrawal and rebound syndromes. This article reviews the pharmacological background of functional blockade or stimulation of receptors of interest in regard to atypical antipsychotics and the implicated potential withdrawal and rebound phenomena. A MEDLINE search was carried out to identify information on withdrawal or rebound syndromes occurring after discontinuation of atypical antipsychotics. Using the resulting literature, we first discuss the theoretical background to the functional consequences of atypical antipsychotic-induced blockade or stimulation of neurotransmitter receptors and, secondly, we highlight the clinical consequences of this. We then review the available clinical literature on switching between atypical antipsychotics, with respect to the occurrence of withdrawal or rebound symptoms. Finally, we offer practical recommendations based on the reviewed findings. The systematic evaluation of withdrawal or rebound phenomena using randomized controlled trials is still understudied. Knowledge of pharmacological receptor-binding profiles may help clinicians in choosing adequate switching or discontinuation strategies for each agent. Results from large switching trials indicate that switching atypical antipsychotics can be performed in a safe manner. Treatment-emergent adverse events during or after switching are not always considered to be, at least in part, associated with the pre-switch antipsychotic. Further studies are needed to substantiate the evidence gained so far on different switching strategies. The use of concomitant medication, e.g., benzodiazepines or anticholinergic drugs, may help to minimize symptoms arising from the discontinuation or switching of antipsychotic treatment.

Jobelyn® pretreatment ameliorates symptoms of psychosis in experimental models.

BACKGROUND: Psychosis is a chronic neurological disorder and it remains a major medical and social problem in most African countries. Individuals with psychotic illness in this region tend to seek help from traditional medical practitioners, who prescribe herbal remedies as alternative forms of treatment for the disease. Jobelyn® (JB) is a commercial polyherbal formulation that has been acclaimed to show beneficial effects in neurological disorders. However, its usefulness in psychosis has not been scientifically validated. Thus, this study was undertaken to evaluate its effects on animal models predictive of human psychosis. METHODS: Antipsychotic activity of JB was assessed based on the inhibition of stereotyped behavior induced by amphetamine or apomorphine in mice. Amphetamine-induced hyperactivity and lethality in aggregated mice were additional tests employed to further evaluate the antipsychotic property of JB. The effect of JB on catalepsy was also assessed, using the inclined plane paradigm. RESULTS: JB (5-50 mg/kg, p.o.) significantly (p<0.05) inhibited stereotypy induced by amphetamine (10.0 mg/kg, i.p.) or apomorphine (1 mg/kg, i.p.), which suggests antipsychotic activity. Furthermore, JB (5-50 mg/kg, p.o.) reduced lethality in aggregated mice and inhibited hyperactivity induced by amphetamine, respectively. However, JB (5-50 mg/kg, p.o.) did not cause cataleptic behavior, as it failed to alter the duration of stay of the animals on the inclined plane. CONCLUSIONS: Taken together, these findings suggest that JB exhibits antipsychotic-like activity, devoid of the adverse effect of cataleptic behavior, and may offer some beneficial effects in the symptomatic relief of psychotic ailments.

MK-801, a NMDA receptor antagonist, increases phosphorylation of histone H3 in the rat medial prefrontal cortex.

BACKGROUND: The present study investigated whether MK-801, when given in doses that cause psychomimetic effects in rats, could alter the phosphorylation of histone 3 (H3) at serine 10 (H3S10p) and the acetylation of H3 at lysine 14 (H3K14ac) in the medial prefrontal cortex (mPFC). These posttranslational modifications of H3 promote chromatin relaxation and increase the probability of gene expression. METHODS: Stereological counting, immunoblot analysis and confocal laser scanning microscopy. RESULTS: Treatment with MK-801 (0.4 mg/kg) evoked a time-dependent increase in the number of H3S10p positive nuclei in both the II/III and V/VI layers of the mPFC, reaching the peak of activation 30 min after injection. MK-801 treatment (0.4 mg/kg) failed to alter H3K14ac. These effects were confirmed by immunoblot analysis on tissue samples from the mPFC. Analysis of cortical cells expressing H3S10p positive nuclei revealed that constitutive and MK-801-induced expression of H3S10p was observed only in neurons and not in glia cells (H3S10p colocalized with NeuN but not with S-100ß). Moreover, it has been found that H3S10p is exclusively present in pyramidal (glutamate-positive) but not in cortical GABA-ergic interneurons (GABA-positive). The effects of MK-801 can be attenuated or blocked by the neuroleptic drug risperidone. In the cortical layer II/III, risperidone was effective at doses of 0.2 and 1 mg/kg, while it was only active at a dose of 1 mg/kg in the V/VI layer. Again, these stereological data were confirmed by immunoblot analysis. CONCLUSIONS: Our results indicate that MK-801 may increase the transcriptional activity of mPFC via the activation of the epigenetic program associated with H3S10p phosphorylation during the course of experimental psychosis.

Can gradual dose titration of ketamine for management of neuropathic pain prevent psychotomimetic effects in patients with advanced cancer?

BACKGROUND: Ketamine is often used to manage neuropathic pain in patients with cancer. However, it occasionally causes psychotomimetic effects such as vivid dreams, nightmares, illusions, hallucinations, and altered body image. OBJECTIVE: To examine whether gradual dose titration of ketamine for management of neuropathic pain prevents psychotomimetic effects in patients with advanced cancer. METHODS: This was a retrospective chart review. We administered ketamine when neuropathic pain in patients with advanced cancer became refractory to opioids and oral adjuvant analgesics. The starting dose of ketamine was 10 mg/d by continuous intravenous infusion. The dose was gradually increased by 10 mg/d every 4 to 6 hours to 50 mg/d or until the pain was relieved. It was subsequently increased by 25 mg/d every 12 to 24 hours until the pain was relieved. RESULTS: For this study, we enrolled 46 patients with advanced cancer. The mean age was 52.2 ± 16.9 years. The mean dose at onset of action and maximum dose of ketamine were 56 ± 58 and 272 ± 214 mg/d, respectively. The mean pain intensity (numerical rating scale) decreased significantly from 7.3 ± 2.0 to 3.5 ± 2.2 after the administration of ketamine (P < .01). The effectiveness was 69.5%. No psychotomimetic effect of less than 300 mg/d was observed during the introduction phase even though psychotropic drugs were not prescribed. Mild sedation was observed in 3 patients (7%) as the only adverse effect during the introduction phase. CONCLUSION: Gradual dose titration of ketamine for management of neuropathic pain can prevent psychotomimetic effects in patients with advanced cancer.

[Treatment of apomorphine infusion adverse effects: subcutaneous nodules and neuropsychiatric complications]. / Tratamiento de los efectos adversos de la apomorfina en infusión: nódulos subcutáneos y complicaciones neuropsiquiátricas.

Subcutaneous nodules and neuropsychiatric complications are the most relevant adverse effects during apomorphine infusion treatment. Subcutaneous nodules appear in almost all the patients and accurate information and training of both patient and caregiver is essential to minimise their impact on the treatment. Although neuropsychiatric complications are not more frequent than with other dopaminergic treatments, they are linked with increasing difficulty of treatment and worsening of patient's quality of life.