Treatment-resistant schizophrenia: How far have we traveled?

Treatment-resistant schizophrenia is a lack of adequate response to antipsychotic medications resulting in incomplete functional and social recovery from the illness. Different definitions have been proposed for clinical practice and research work. Antipsychotics that are used in the management of schizophrenia mainly act on multiple dopaminergic pathways which are implicated in the development of symptoms of schizophrenia. Newer antipsychotics also are implicated to affect the serotonergic pathways. Clozapine is the only evidence-based treatment available for the management of treatment-resistant cases. Neurobiologically, there is a considerable overlap between treatment-resistant and treatment-responsive cases. The factors that are implicated in the evolution of treatment resistance are still not conclusive. These make the management of such patients a challenge. However, certain peculiarities of treatment-resistant schizophrenia have been identified which can guide us in the early identification and precise treatment of the treatment-resistant cases.

An Overview of Mucosa-Associated Protozoa: Challenges in Chemotherapy and Future Perspectives

Parasitic infections caused by protozoans that infect the mucosal surfaces are widely neglected worldwide. Collectively, Entamoeba histolytica, Giardia lamblia, Cryptosporidium spp. and Trichomonas vaginalis infect more than a billion people in the world, being a public health problem mainly in developing countries. However, the exact incidence and prevalence data depend on the population examined. These parasites ultimately cause pathologies that culminate in liver abscesses, malabsorption syndrome, vaginitis, and urethritis, respectively. Despite this, the antimicrobial agents currently used to treat these diseases are limited and often associated with adverse side effects and refractory cases due to the development of resistant parasites. The paucity of drug treatments, absence of vaccines and increasing problems of drug resistance are major concerns for their control and eradication. Herein, potential candidates are reviewed with the overall aim of determining the knowledge gaps and suggest future perspectives for research. This review focuses on this public health problem and focuses on the progress of drug repositioning as a potential strategy for the treatment of mucosal parasites.

The Storm Before the Calm: Ablation of Premature Ventricular Complex Trigger for Incessant Ventricular Fibrillation

Ventricular tachycardia storm is associated with high mortality rates and is often refractory to treatment. Historically, few options for treatment have existed in cases when antiarrhythmic drugs fail. We report the case of a patient with incessant ventricular fibrillation (VF) in the postinfarction period that was triggered by premature ventricular contractions (PVCs) that persisted despite normal electrolytes, exclusion of ongoing ischemia, infusions of antiarrhythmic drugs, general anesthesia, full circulatory support with extracorporeal membranous oxygenation, and cardiac sympathetic denervation. Given that the VF appeared to be triggered consistently by a unifocal, short-coupled PVC (consistent with Purkinje fiber–mediated VF), we performed catheter ablation, after which point, the patient experienced no further PVCs or ventricular arrhythmia. This case serves as a reminder of three key teaching points. First, not all VF is created equal, with some cases being chiefly the result of a vulnerable substrate and others being best accounted for by frequent triggers. Second, examining the available electrocardiographic data and appropriately interpreting them can guide the selection of therapies up to and including catheter ablation for treatment-refractory VF. Third, full circulatory support greatly facilitates successful electroanatomic mapping and catheter ablation of unstable ventricular arrhythmias.

Clozapine in the treatment of refractory schizophrenia: a practical guide for healthcare professionals

BACKGROUND

Clozapine remains the only medication licensed for treating refractory schizophrenia. However, it remains underutilized in part due to concerns regarding adverse events.

SOURCES OF DATA

Published literature.

AREAS OF AGREEMENT

Common adverse events during clozapine treatment include sedation, hypersalivation, postural hypotension, dysphagia, gastrointestinal hypomotility, weight gain, diabetes mellitus and dyslipidaemia. Rare but serious events include agranulocytosis, cardiomyopathy, myocarditis, pneumonia, paralytic ileus and seizure.

AREAS OF CONTROVERSY

It remains unclear how best to minimize clozapine-induced morbidity/mortality (i) during dose titration, (ii) from hypersalivation and (iii) from gastrointestinal hypomotility. It is also unclear how clozapine pharmacokinetics are affected by (i) gastrointestinal hypomotility, (ii) systemic infection and (iii) passive exposure to cigarette smoke. Whether monthly haematological monitoring needs to continue after 12 months of uninterrupted therapy is also a subject of debate.

GROWING POINTS

There is a need for better management of serious clozapine-related adverse events in addition to agranulocytosis. There is also a need for better education of patients and carers, general practitioners, A&E and ITU staff and others of the problems posed in using clozapine safely.

AREAS TIMELY FOR DEVELOPING RESEARCH

There is a need for more research on assessing clozapine dosage (i) as patients get older, (ii) with respect to exposure to cigarette smoke and (iii) optimizing response if adverse events or other factors limit dosage.

Use of Noninvasive Ventilation with Volume-assured Pressure Support for Treatment-refractory Myasthenia Gravis

Background: Stepwise approach to therapy and increasing use of immunosuppressive agents have led to increasingly good prognosis and survival in myasthenia gravis (MG). However, there is a small subset of patients with treatment-refractory disease who experience a higher disease burden and increased rates of myasthenic crises and exacerbations, including respiratory failure. A 54-year-old man with treatment-refractory MG on chronic plasma exchange therapy had rapidly fluctuating weakness, poor sleep quality, and worsening respiratory symptoms in between treatments. He was started on home nocturnal noninvasive ventilation with volume-assured pressure support mode and experienced marked improvement in sleep quality, dyspnea, fatigue, and daytime sleepiness.

The use of omalizumab for treatment-refractory chronic spontaneous urticaria in a West Australian outpatient cohort

There is a lack of real-world data on the use of omalizumab in treatment-refractory chronic spontaneous urticaria (CSU). A single-centre retrospective cohort study was performed to assess the efficacy and safety of omalizumab for treatment-refractory CSU. The overall response rate of 67% is comparable with that reported in the literature. Disease control and sustained remission can be achieved with omalizumab, even in patients with treatment-resistant CSU.

Deep brain stimulation in the treatment of obsessive-compulsive disorder: current perspectives

Deep brain stimulation (DBS) is a neuro-psychosurgical technique widely accepted in movement disorders, such as Parkinson's disease. Since 1999, DBS has been explored for severe, chronic and treatment-refractory psychiatric diseases. Our review focuses on DBS in obsessive-compulsive disorder (OCD), considered as a last treatment resort by most of learned societies in psychiatry. Two main stimulation areas have been studied: the striatal region and the subthalamic nucleus. But, most of the trials are open-labeled, and the rare controlled ones have failed to highlight the most efficient target. The recent perspectives are otherwise encouraging. Indeed, clinicians are currently considering other promising targets. A case series of 2 patients reported a decrease in OCD symptoms after DBS in the medial forebrain bundle and an open-label study is exploring bilateral habenula stimulation. New response criteria are also investigating such as quality of life, or subjective and lived-experience. Moreover, first papers about cost-effectiveness which is an important criterion in decision making, have been published. The effectiveness of tractography-assisted DBS or micro-assisted DBS is studying with the aim to improve targeting precision. In addition, a trial involving rechargeable pacemakers is undergoing because this mechanism could be efficient and have a positive impact on cost-effectiveness. A recent trial has discussed the possibility of using combined cognitive behavioral therapy (CBT) and DBS as an augmentation strategy. Finally, based on RDoc Research, the latest hypotheses about the understanding of cortico-striato-thalamo-cortical circuits could offer new directions including clinical predictors and biomarkers to perform adaptive closed-loop systems in the next future.

Deep brain stimulation for treatment-refractory obsessive compulsive disorder: a systematic review

BACKGROUND

Obsessive-compulsive disorder is one of the most disabling of all psychiatric illnesses. Despite available pharmacological and psychotherapeutic treatments about 10% of patients remain severely affected and are considered treatment-refractory. For some of these patients deep brain stimulation offers an appropriate treatment method. The scope of this article is to review the published data and to compare different target structures and their effectiveness.

METHODS

PubMed search, last update June 2013, was conducted using the terms "deep brain stimulation" and "obsessive compulsive disorder".

RESULTS

In total 25 studies were found that reported five deep brain stimulation target structures to treat obsessive-compulsive disorder: the anterior limb of the internal capsule (five studies including 14 patients), nucleus accumbens (eight studies including 37 patients), ventral capsule/ventral striatum (four studies including 29 patients), subthalamic nucleus (five studies including 23 patients) and inferior thalamic peduncle (two studies including 6 patients). Despite the anatomical diversity, deep brain stimulation treatment results in similar response rates for the first four target structures. Inferior thalamic peduncle deep brain stimulation results in higher response rates but these results have to be interpreted with caution due to a very small number of cases. Procedure and device related adverse events are relatively low, as well as stimulation or therapy related side effects. Most stimulation related side effects are transient and decline after stimulation parameters have been changed.

CONCLUSION

Deep brain stimulation in treatment-refractory obsessive-compulsive disorder seems to be a relatively safe and promising treatment option. However, based on these studies no superior target structure could be identified. More research is needed to better understand mechanisms of action and response predictors that may help to develop a more personalized approach for these severely affected obsessive compulsive patients.

Effectiveness of methylphenidate as augmentation therapy after failure of adjunctive neuromodulation for patients with treatment-refractory bipolar depression: a case report

Adjunctive use of methylphenidate, a central stimulant, has been considered as a potential therapeutic choice for patients with refractory unipolar, geriatric, or bipolar depression, and depression secondary to medical illness. We present a case of bipolar depression in which the patient responded significantly to augmentation with methylphenidate, without any side effects, after failure of adjunctive repetitive transcranial magnetic stimulation and electroconvulsive therapy. Mr U, a 56-year-old man with bipolar I disorder, had melancholic symptoms during his sixth episode of bipolar depression. After failure of repetitive transcranial magnetic stimulation and electroconvulsive therapy, he was treated with fluoxetine 80 mg/day, duloxetine 360 mg/day, mirtazapine 60 mg/day, and sodium valproate 1,000 mg/day, with no improvement. We added methylphenidate at a dose of 10 mg/day for one week, which resulted in mild clinical improvement, and then methylphenidate extended-release 20 mg/day for one week, with significant clinical improvement. He tolerated his medications well. His clinical recovery was stable over one year. The patient's antidepressants and methylphenidate were gradually tapered and finally discontinued after one year with no withdrawal syndrome. To date, he remains well on sodium valproate as monotherapy and is being followed up at our bipolar department. This case suggests that methylphenidate augmentation might be a therapeutic option when treating highly treatment-resistant patients with bipolar depression, even if they had not responded to adjunctive neuromodulation. In these clinical situations, physicians might be interested in prescribing methylphenidate because of its efficacy and safety.

Treatment-resistant Obsessive-compulsive Disorder in Young People: Assessment and Treatment Strategies

Cognitive behaviour therapy (CBT) and selective serotonin reuptake inhibitors have both been established as effective interventions for paediatric obsessive-compulsive disorder (OCD), with CBT being the recommended first-line treatment in most cases. While the majority of young people respond well to these treatments, a significant proportion remain symptomatic. Although the research on treatment-resistant OCD remains limited, increasing empirical attention is being paid to predictors of treatment outcome in young people with OCD, and efforts are being made to identify the factors that hinder recovery. This article outlines potential barriers in treatment and highlights strategies for optimising outcome, with particular focus on cognitive behavioural techniques.

Treatment-refractory, juvenile-onset bipolar affective disorder

A case of juvenile-onset bipolar affective disorder with a childhood history of attention-deficit hyperactivity disorder (ADHD) is presented. As the patient was refractory to treatment with mood stabilizers, clozapine was given, which succeeded in achieving remission. The disorder's natural history needs further study. Data also need to be collected for optimal pharmacotherapeutic guidance.

Failure to respond to treatment with typical antipsychotics is not associated with CYP2D6 ultrarapid hydroxylation

AIMS

To investigate whether or not there is a correlation between failure to respond to typical antipsychotics and CYP2D6 ultrarapid metaboliser status.

METHODS

CYP2D6 phenotype (metaboliser status) was assigned following genotyping for gene duplication, as well as for the CYP2D6*3, CYP2D6*4, and CYP2D6*5 null alleles in 235 treatment-refractory patients and 73 nonrefractory patients.

RESULTS

Four (1.7%) of the 235 treatment-refractory subjects were positive on the duplication assay, but, of these, two were found to represent duplications of a null allele (CYP2D6*4 ), therefore leaving only two (0.85%) positive for duplication of a wild type allele (ultrarapid metabolisers). Three (4.1%) of the nonrefractory subjects had a genotype consistent with ultrarapid metaboliser status. Fisher's exact test gave a two-tailed P value of 0.091, i.e. a trend towards an excess of ultrarapid metabolisers in the nonrefractory group, which was in the opposite direction to that predicted by our hypothesis.

CONCLUSIONS

Although the results show a trend towards an excess of ultrarapid metabolisers in the nonrefractory group, the percentages in the two groups of patients are both within the range for ultrarapid metabolisers in Caucasian populations. Our data are not consistent with ultrarapid metaboliser status being a major cause of failure to respond to typical antipsychotics.