Rational Use of Second-Generation Antipsychotics for the Treatment of ICU Delirium

The Role of Quetiapine in Treating Delirium in Critical Care Settings: A Narrative Review

Delirium is a frequent complication in critically ill patients, often leading to worse clinical outcomes, prolonged ICU stays, and an increased healthcare burden. Its identification has become more consistent with the adoption of validated diagnostic tools, allowing clinicians to recognize and address this condition more effectively. Although delirium can arise from direct neurological dysfunction, it is frequently a consequence of systemic conditions such as sepsis or organ failure. Therefore, a comprehensive evaluation of underlying causes is essential before initiating pharmacological treatment. Among the pharmacological options, quetiapine has gained attention for its use in ICU patients with delirium. Compared to first-generation antipsychotics, it is often preferred due to its sedative effects and more favorable safety. However, current clinical guidelines remain inconclusive regarding its routine use, as evidence supporting its efficacy is limited. One of the main challenges is the heterogeneity of patient populations included in randomized trials, making it difficult to determine whether specific subgroups may benefit more from treatment. This narrative review explores the pharmacological properties of quetiapine, its potential role in managing ICU delirium, and the current state of evidence regarding its safety and effectiveness.

Olanzapine for the treatment of ICU delirium: a systematic review and meta-analysis

Background

As an atypical antipsychotic drug, olanzapine is one of the most commonly used drugs for delirium control. There are no systematic evaluations or meta-analyses of the efficacy and safety of olanzapine for delirium control in critically ill adults.

Objectives

In this meta-analysis, we evaluated the efficacy and safety of olanzapine for delirium control in critically ill adults in the intensive care unit (ICU).

Data Sources and Methods

From inception to October 2022, 12 electronic databases were searched. We retrieved randomized controlled trials (RCTs) and retrospective cohort studies of critically ill adults with delirium that compared the effects of olanzapine and other interventions, including routine care (no intervention), nonpharmaceutical interventions and pharmaceutical interventions. The main outcome measures were the (a) relief of delirium symptoms and (b) a decrease in delirium duration. Secondary outcomes were ICU and in-hospital mortality, ICU and hospital length of stay, incidence of adverse events, cognitive function, sleep quality, quality of life, mechanical ventilation time, endotracheal intubation rate and delirium recurrence rate. We applied a random effects model.

Results

Data from 10 studies (four RCTs and six retrospective cohort studies) involving 7076 patients (2459 in the olanzapine group and 4617 in the control group) were included. Olanzapine did not effectively relieve delirium symptoms (OR = 1.36, 95% CI [0.83, 2.28], p = 0.21), nor did it shorten the duration of delirium [standardized mean difference (SMD) = 0.02, 95% CI [-1.04, 1.09], p = 0.97] when compared with other interventions. Pooled data from three studies showed that the use of olanzapine reduced the incidence of hypotension (OR = 0.44, 95% CI [0.20, 0.95], p = 0.04) compared with other pharmaceuticals. There was no significant difference in other secondary outcomes, including ICU or hospital length of stay, in-hospital mortality, extrapyramidal reactions, QTc interval prolongation, or overall incidence of other adverse reactions. The number of included studies was not sufficient for performing a comparison between olanzapine and no intervention.

Conclusion

Compared with other interventions, olanzapine has no advantage in alleviating delirium symptoms and shortening delirium duration in critically ill adults. However, there is some evidence that the rate of hypotension was lower in patients who received olanzapine than in those who received other pharmaceutical interventions. There was a nonsignificant difference in the length of ICU or hospital stay, in-hospital mortality, and other adverse reactions. This study provides reference data for delirium research and clinical drug intervention strategies in critically ill adults.

Registration

Prospective Register of Systematic Reviews (PROSPERO; registration number CRD42021277232).

The emerging role of olanzapine in paediatric CINV control: A review

Chemotherapy-induced nausea and vomiting (CINV) is a serious side effect of chemotherapy that negatively impacts the quality of life of oncological patients and is associated with the emetogenic risk specific to administered chemotherapy. Current practice guidelines on the use of antiemetics in CINV include the option of adding olanzapine to antiemetic regimens in the management of adult CINV. The use of olanzapine in pediatric CINV has been restricted to children with poor CINV control. Research on the use of olanzapine in pediatric CINV has been limited. The aim of this review was to evaluate current evidence on the effective and safe antiemetic use of olanzapine in pediatric CINV of any type following chemotherapy of any emetogenicity. Ovid MEDLINE, Embase, CENTRAL databases were searched for any literature on the use of olanzapine in pediatric CINV published from 2015 to 2022. Studies that reported on the olanzapine-containing antiemetic regimen in peadiatric CINV control specifically were included. Search restrictions were placed on research published in English. The search generated 43 records that were assessed for eligibility. Out of 10 identified eligible studies a third were RCT. Findings of this review suggest that adding olanzapine to antiemetic regimen in pediatric CINV control is a worthwhile consideration. Further research is needed to establish the efficacy and safety of antiemetic olanzapine use in pediatric CINV.

Delirium in hospitalized older adults

Delirium is a common and underdiagnosed problem in hospitalized older adults. It is associated with an increased risk of poor cognitive and functional outcomes, institutionalization, and death. Timely diagnosis of delirium and non-pharmacological prevention and management strategies can improve patient outcomes. The Confusion Assessment Method (CAM) is the most widely used clinical assessment tool for the diagnosis of delirium. Multiple variations of the CAM have been developed for ease of administration and for the unique needs of specific patient populations, including the 3-min diagnostic CAM (3D CAM), CAM-Intensive Care Unit (CAM-ICU), Delirium Triage Screen (DTS)/Brief CAM (b-CAM), 4AT tool, and ultrabrief delirium assessment. Strong evidence supports the effectiveness of nonpharmacologic strategies as the primary intervention for the prevention of delirium. Multicomponent delirium prevention strategies can reduce the incidence of delirium by 40%. Investigation of underlying medical precipitants and optimization of non-pharmacological interventions are first line in the management of delirium. Despite a lack of evidence supporting use of antipsychotics, low dose antipsychotics remain second line for off-label treatment of distressing psychoses and/or agitated behaviors that are refractory to non-pharmacological behavioral interventions and pose an imminent risk of harm to self or others. Any antipsychotic prescription for delirium should be accompanied by an appropriate taper plan. Follow up with primary care providers on discharge from hospital for ongoing screening of cognitive impairment is important.

Efficacy of Low-Dose Prophylactic Quetiapine on Delirium Prevention in Critically Ill Patients: A Prospective, Randomized, Double-Blind, Placebo-Controlled Study

Purpose: To evaluate the efficacy of short-term low-dose quetiapine for delirium prevention in critically ill patients. Methods: In this prospective, a single-center, randomized, double-blind, placebo-controlled trial, adult patients who were admitted from July 2015 to July 2017 to a medical intensive care unit (ICU) of a tertiary teaching hospital affiliated to Seoul National University were included. Quetiapine (12.5 mg or 25 mg oral at night; N = 16) or placebo (N = 21) was administered according to randomization until ICU discharge or the 10th ICU day. The primary endpoint was the incidence of delirium within the first 10 ICU days. Secondary endpoints included the rate of positive Confusion Assessment Method for the ICU (CAM-ICU) (the number of positive CAM-ICU counts/the number of total CAM-ICU counts), delirium duration, successful extubation, and overall mortality. Result: The incidence of delirium during the 10 days after ICU admission was 46.7% (7/15) in the quetiapine group and 55.0% (11/20) in the placebo group (p = 0.442). In the quetiapine group, the rate of positive CAM-ICU was significantly lower than in the placebo group (14.4% vs. 37.4%, p = 0.048), delirium duration during the study period was significantly shorter (0.28 day vs. 1.83 days, p = 0.018), and more patients in the quetiapine than in the placebo group were weaned from mechanical ventilation successfully (84.6% vs. 47.1%, p = 0.040). Conclusions: Our study suggests that prophylactic use of low-dose quetiapine could be helpful for preventing delirium in critically ill patients. A further large-scale prospective study is needed.

Current controversies and future perspectives on treatment of intensive care unit delirium in adults

Delirium is the most frequent manifestation of acute brain dysfunction in intensive care unit (ICU). Although antipsychotics are widely used to treat this serious complication, recent evidence has emphasized that these agents did not reduce ICU delirium (ICU-D) prevalence and did not improve survival, length of ICU or hospital stay after its occurrence. Of note, no pharmacological strategy to prevent or treat delirium has been identified, so far. In this scenario, new scientific evidences are urgently needed. Investigations on specific ICU-D subgroups, or focused on different clinical settings, and studies on medications other than antipsychotics, such as dexmedetomidine or melatonin, may represent interesting fields of research. In the meantime, because there is some evidence that ICU-D can be effectively prevented, the literature suggests strengthening all the strategies aimed at prevention through no-pharmacological approaches mostly focused on the correction of risk factors. The more appropriate strategy useful to treat established delirium remains the use of antipsychotics managed by choosing the right doses after a careful case-by-case analysis. While the evidence regarding the use of dexmedetomidine is still conflicting and sparse, this drug offers interesting perspectives for both ICU-D prevention and treatment. This paper aims to provide an overview of current pharmacological approaches of evidence-based medicine practice. The state of the art of the on-going clinical research on the topic and perspectives for future research are also addressed.

Antipsychotics, Delirium, and Acute Respiratory Distress Syndrome: What Is the Link?

Acute respiratory distress syndrome (ARDS) is an acute inflammatory process that impairs the ability of the lungs to oxygenate and ultimately leads to respiratory failure. Patients who develop ARDS often have prolonged and complicated hospital courses putting them at risk for intensive care unit (ICU) delirium. Patients with ICU delirium often need chemical sedation, mechanical ventilation, prolonged duration of ICU and hospital stays, and they experience long-term cognitive impairment and increased mortality. In a patient with ARDS, ICU delirium further complicates the hospital course and increases the risk of morbidity and mortality. Antipsychotics are prescribed to decrease the severity and duration of ICU delirium, thus potentially decreasing their risk of morbidity and mortality. However, antipsychotics are associated with many adverse effects including respiratory failure. Given the long-term sequelae associated with the development of ICU delirium and the risks associated with antipsychotic use, clinicians must weigh the risks and benefits of antipsychotic use. This review investigates the interrelationship between ARDS, delirium, and antipsychotic use. In addition to discussing relevant studies evaluating antipsychotics for the prevention and treatment of delirium, we investigate safety concerns with the use of antipsychotics, especially as they relate to ARDS. Using the data compiled in this review, clinicians can make an informed decision about the use of antipsychotics for the prevention or treatment of delirium, with special consideration for their patients with ARDS. Future studies are needed to critically evaluate antipsychotic timing, dose, and duration for the prevention and treatment of ICU delirium and specifically evaluate the impact in special populations, particularly patients with ARDS.