Delirium resolving upon switching from risperidone to quetiapine: implication of CYP2D6 genotype

Predicting new drug indications based on double variational autoencoders

Experimental drug development is costly, complex, and time-consuming, and the number of drugs that have been put into application treatment is small. The identification of drug-disease correlations can provide important information for drug discovery and drug repurposing. Computational drug repurposing is an important and effective method that can be used to determine novel treatments for diseases. In recent years, an increasing number of large databases have been utilized for biological data research, particularly in the fields of drugs and diseases. Consequently, researchers have begun to explore the application of deep neural networks in biological data development. One particularly promising method for unsupervised learning is the deep generative model, with the variational autoencoder (VAE) being among the mainstream models. Here, we propose a drug indication prediction algorithm called DIDVAE (predicting new drug indications based on double variational autoencoders), which generates new data by learning the latent variable distribution of known data to achieve the goal of predicting drug-disease associations. In the experiment, we compared the DIDVAE algorithm with the BBNR, DrugNet, MBiRW and DRRS algorithms on a unified dataset. The comprehensive experimental results show that, compared with these prediction algorithms, the DIDVAE algorithm provides an overall improved prediction. In addition, further analysis and verification of the predicted unknown drug-disease association also proved the practicality of the method.

Pharmacogenetics of Risperidone: A Systematic Review of the Clinical Effects of CYP2D6 Polymorphisms

OBJECTIVE

To summarize and evaluate the pharmacogenetic literature pertaining to the effects of CYP2D6 polymorphism on clinical outcomes of risperidone therapy.

DATA SOURCES

A systematic literature search was performed using the search terms risperidone, pharmacogenetics, cytochrome P-450 enzyme system, cytochrome P-450 CYP2D6, and polymorphism (genetic) in MEDLINE (1946-October 2012), EMBASE (1980-October 2012), PubMed (1947-October 2012), International Pharmaceutical Abstracts (1970-October 2012), and Google Scholar.

STUDY SELECTION AND DATA EXTRACTION

Identified articles were included if they measured the association between CYP2D6 genetic polymorphisms and clinical outcomes in at least 2 patients taking risperidone. The data elements extracted from these articles consisted of study design, number of subjects, indication for risperidone therapy, CYP2D6 phenotype status, mean daily dose of risperidone, and effects on clinical outcomes.

DATA SYNTHESIS

The identified citations consisted of 10 prospective nonrandomized, uncontrolled cohort studies, 1 retrospective cohort study, 1 prospective case-control study, and 1 retrospective case series. Studies were of variable quality and none provided high-quality evidence; they included heterogeneous patient populations with varying clinical diagnoses and drug therapy regimens. Most studies reported nonsignificant trends but were limited by power to detect statistical significance and short trial duration. However, increased risk of adverse effects (including QT interval prolongation) was observed in patients with inactive alleles.

CONCLUSIONS

While there were trends toward increased adverse effects in poor metabolizers, most outcomes were not significant. As such, routine genotyping should not be used for screening. Future usefulness cannot be ruled out, as many studies had significant limitations that preclude determination of clinical relevance. Adequately powered clinical and epidemiologic studies are warranted to clarify the role of CYP2D6 genotyping in practice.

Comparative effectiveness of quetiapine and haloperidol in delirium: A single blind randomized controlled study

AIM

To evaluate the effectiveness of quetiapine and haloperidol in patients of delirium referred to psychiatry consultation liaison services.

METHODS

The study followed a single blind randomised controlled trial design. Thirty-two patients in the haloperidol group and 31 patients in the quetiapine group were assessed at the baseline and 6 consecutive days. Flexible dosing regimen (haloperidol: 0.25-1.25 mg; quetiapine 12.5-75 mg/d) was used. Delirium Rating Scale-Revised-98 (DRS-R-98) and mini mental status examination (MMSE) were the primary and secondary efficacy measures respectively.

RESULTS

Baseline DRS-R-98 severity score and MMSE scores did not differ between the 2 study groups. From baseline to day 6, there was significant reduction in the total DRS-R-98 scores, DRS-R-98 cognitive domain scores, DRS-R-98 non-cognitive domain scores and significant increase in the MMSE scores in both the groups. Both the groups did not differ on any of the assessments in terms of DRS-R98 and MMSE scores. The effectiveness of both the medications was similar in adult and elderly (≥ 60 years) patients. At the end of the trial, 68.75% and 67.74% of subjects in the haloperidol and quetiapine group respectively had mean DRS-R-98 scores below 10. By 6^th day, 12 (37.5%) patients in haloperidol group and 9 (29.03%) patients in the quetiapine group had DRS-R98 score of “0” with no significant difference between the two groups (P = 0.47).

CONCLUSION

Quetiapine is as effective as haloperidol in the management of delirium.

Delirium in palliative medicine: a review

Delirium is a devastating complication of general medical and surgical populations but of particular importance in palliative medicine. It is a clinical syndrome that is often not recognized and, therefore, not treated appropriately. The presence of delirium is a predictor of increased morbidity and mortality, longer hospitalization, and more likely discharge to a nursing facility. This article reviews the pathophysiology, etiology, diagnosis, and treatment of delirium in the palliative medicine population.

[Informed Consent and the Approval by Ethics Committees of Studies Involving the Use of Atypical Antipsychotics in the Management of Delirium]

INTRODUCTION

Delirium is an acute alteration of consciousness and cognition. Atypical antipsychotics (AA) have recently become a main part of its treatment. Studies in this population generate a series of ethical dilemmas concerning the voluntary participation of patients and their state of vulnerability since their mental faculties are, by definition, compromised.

OBJECTIVE

To assess whether studies with AA for the treatment of delirium obtained an approval by an ethics committee on human research (ECHR), if an informed consent (IC) was obtained, whether the IC was verbal or written, and who gave the approval to participate.

METHOD

Systematic review of Medline for studies of delirium where quetiapine and olanzapine were the main treatment, assessing the existence of an ECHR approval and implementation of an IC.

RESULTS

11 studies were identified (6 of quetiapine and 5 of olanzapine). 5 had an ECHR approval.

CONCLUSIONS

Most studies examining the treatment of delirium with quetiapine or olanzapine were not subject to approval by an ECHR and most of them did not obtain an IC from the patient's legal guardian. It is essential that future studies of antipsychotics and other drugs for the treatment of delirium have the protocol approved by an ECHR and a written IC signed by the patient's legal representative, since by definition delirium is a condition that compromises superior mental processes.

Risperidone-induced bulbar palsy-like syndrome

There have been several case reports of risperidone-associated dysphagia. Risperidone-induced bulbar palsy-like syndrome has not been previously described. We report on a 58-year-old gentleman with prior history of schizophrenia and remote chlorpromazine use with no history of extrapyramidal symptoms who experienced acute onset of dysphagia and facial diplegia with hyperprolactinemia while being treated with risperidone. To date there have been five reported cases of dysphagia associated with risperidone, occurring by such mechanisms as isolated pharyngeal dysfunction from pharyngeal constrictor palsy and dystonia, drug-induced parkinsonism, and acute dystonic reaction. These cases were associated either with initiation or up-titration of risperidone, with complete resolution of dysphagia after medication discontinuation or dose change. Our patient developed dysphagia within 2 weeks of taking risperidone and completely resolved 1 month after the medication was stopped. Unlike other reported cases, our patient also experienced symptomatic hyperprolactinemia, another known side effect of risperidone. Physicians should also be aware that risperidone can be associated with oropharyngeal dysphagia secondary to an acute bulbar palsy-like syndrome that places patients at increased risk of aspiration events and its associated morbidity and mortality.

Delirium in the acute care setting: characteristics, diagnosis and treatment

Delirium is a neurobehavioral syndrome caused by the transient disruption of normal neuronal activity secondary to systemic disturbances. It is also the most common psychiatric syndrome found in the general hospital setting, its prevalence surpassing better known psychiatric disorders. This article reviews the published literature on delirium and addresses the epidemiology, known etiologic factors, presentation and characteristics of delirium, while emphasizing what is known about treatment strategies and prevention. Given increasing evidence that delirium is not always reversible and the many sequelae associated with its development, physicians must do everything possible to prevent its occurrence or shorten its duration, by recognizing its symptoms early, correcting underlying contributing causes, and using treatment strategies proven to help recover functional status.

The importance of diagnosing and managing ICU delirium

ICU delirium represents a form of brain dysfunction that in many cohorts has been diagnosed in 60 to 85% of patients receiving mechanical ventilation. This organ dysfunction is grossly underrecognized because a majority of patients have hypoactive or "quiet" delirium characterized by "negative" symptoms (eg, inattention and a flat affect) not alarming the treating team. Hyperactive delirium, formerly called ICU psychosis, stands out because of symptoms such as agitation that may cause harm to self or staff, but is actually rare relative to hypoactive delirium and associated with a better prognosis. Delirium is often incorrectly thought to be transient and of little consequence. After adjusting for numerous covariates, delirium is a strong, independent predictor of prolonged length of stay, reintubation, higher mortality, and cost of care. Expanded work on patient safety and recommendations by professional societies have established the importance of delirium monitoring and recommended it as standard practice in ICUs all over the world. This evidence-based review for physicians, nurses, respiratory therapists, and pharmacists will outline why it is imperative that patients be routinely monitored for delirium. This review will discuss modifiable risk factors for delirium, such as metabolic disturbances or potent sedative and analgesic medications. Attention to mitigating risk factors, along with recommended pharmacologic approaches such as antipsychotic medications, may provide resolution of delirium in some patients, while others will persist with refractory brain dysfunction and long-term cognitive impairment following critical illness.