There is concern that hydroxyzine exacerbates delirium, but a recent preliminary study suggested that the combination of haloperidol and hydroxyzine was effective against delirium. This study examined whether the concomitant use of hydroxyzine and haloperidol worsened delirium in patients with cancer.

This retrospective, observational study was conducted at 2 general hospitals in Japan. The medical records of patients with cancer who received haloperidol for delirium from July to December 2020 were reviewed. The treatments for delirium included haloperidol alone or haloperidol combined with hydroxyzine. The primary outcome was the duration from the first day of haloperidol administration to the resolution of delirium, defined as its absence for 2 consecutive days. The time to delirium resolution was analyzed to compare the haloperidol group and hydroxyzine combination group using the log-rank test with the Kaplan–Meier method. Secondary outcomes were (1) the total dose of antipsychotic medications, including those other than haloperidol (measured in chlorpromazine-equivalent doses), and (2) the frequencies of detrimental incidents during delirium, specifically falls and self-removal of drip infusion lines. The unpaired t-test and Fisher’s exact test were used to analyze secondary outcomes.

Of 497 patients who received haloperidol, 118 (23.7%) also received hydroxyzine. No significant difference in time to delirium resolution was found between the haloperidol group and the hydroxyzine combination group (log-rank test, P = 0.631). No significant difference between groups was found in either chlorpromazine-equivalent doses or the frequency of detrimental incidents.

This study showed that the concomitant use of hydroxyzine and haloperidol did not worsen delirium in patients with cancer.

We investigated the influence of oral cannabidiol (CBD) on vacuous chewing movements (VCM) and oxidative stress parameters induced by short- and long-term administration of haloperidol in a rat model of tardive dyskinesia (TD).

Haloperidol was administered either sub-chronically via the intraperitoneal (IP) route or chronically via the intramuscular (IM) route to six experimental groups only or in combination with CBD. VCM and oxidative stress parameters were assessed at different time points after the last dose of medication.

Oral CBD (5 mg/kg) attenuated the VCM produced by sub-chronic administration of haloperidol (5 mg/kg) but had minimal effects on the VCM produced by chronic administration of haloperidol (50 mg/kg). In both sub-chronic and chronic haloperidol groups, there were significant changes in brain antioxidant parameters compared with CBD only and the control groups. The sub-chronic haloperidol-only group had lower glutathione activity compared with sub-chronic haloperidol before CBD and the control groups; also, superoxide dismutase, catalase, and 2,2-diphenyl-1-picrylhydrazyl activities were increased in the sub-chronic (IP) haloperidol only group compared with the CBD only and control groups. Nitric oxide activity was increased in sub-chronic haloperidol-only group compared to the other groups; however, the chronic haloperidol group had increased malondialdehyde activity compared to the other groups.

Our findings indicate that CBD ameliorated VCM in the sub-chronic haloperidol group before CBD, but marginally in the chronic haloperidol group before CBD. There was increased antioxidant activity in the sub-chronic group compared to the chronic group.

Haloperidol is a first generation, high potency, low cost and widely used antipsychotic. There are inconsistencies in the literature about comparison of effectiveness between long-acting injectable haloperidol (HDLAI) with oral haloperidol (OH), as well as the combined use of both formulations (HDLAI+OH).

To verify whether HDLAI reduces the number of emergency visits and hospitalizations when compared to oral OH, or in combination therapy HDLAI+OH.

Retrospective observational study on a Psychiatric Emergency department, including patients aged 18 to 60 years, both genders, under continuous treatment for at least 5 months with Haloperidol for any psychiatric illness, divided into 3 groups of patients (HDLAI, OH, HDLAI+OH). Dependent variables: visits and admissions. Independent variables: sex and age. Data were checked for normality (Kolmogorov-Smirnov test) and homoscedasticity (Bartlett test). For comparison of average number of visits and hospitalizations of patients Kruskal-Wallis test followed by Dunn’s multiple comparison test was used. It was considered statistically significant if p < 0.05. This study was approved by the Ethics Committee of Maringá State University.

No statistical difference between groups HDLAI and OH was found. The HDLAI+OH group presented higher means of emergency visits and hospitalizations with statistical significance.

It suggests the use of HDLAI can be considered an alternative as effective as oral intake. Prolonged use of associated HDLAI and oral supplementation leads to worst outcomes.

No significant relationships.

Schizophrenia is one of the most severe mental disorders. Haloperidol and other first-generation antipsychotics are widely used for schizophrenia treatment, but have prominent side effects, primarily extrapyramidal symptoms (EPS). The EPS severity is highly variable and may be underlied by genetic factors.

We performed a prospective study to test the association of DRD2/ANKK1 Taq1A polymorphism (rs18000497) and CYP2D6 phenotype, predicted from genotypes using 8 CYP2D6 alleles (*3, *4, *5, *6,*9, *10,*41, xN) with EPS severity during haloperidol treatment in schizophrenia spectrum disorders patients.

57 inpatients with schizophrenia spectrum disorders (42,1% females; mean age - 46,7±11,8 y.o (M±SD) of European ancestry were enrolled in the study. Abnormal Involuntary Movement Scale (AIMS), Barnes Akathisia Rating Scale (BARS), Simpson-Angus Scale (SAS) were used to assess EPS on two timepoints: day 1 and day 21 of haloperidol treatment.

TaqIA T-allele carriers in contrast to wild-type allele homozygous patients had higher scores of BARS (p=0.029) and SAS (p=0.024) on day 21. After stratification by CYP2D6 phenotype, these differences were observed only in extensive metabolizers (p=0.006 and p=0.001 respectively), although the CYP2D6 phenotype itself was not associated with EPS severity. The combined effect of TaqIA T allele with CYP2D6 extensive phenotype on BARS score on day 21 was confirmed by General Linear Model (p=0.013).

Our results show that minor TaqIA T-allele is associated with the severity of EPS after 3 weeks of haloperidol treatment only in CYP2D6 extensive metabolizers. That highlights the importance of using both pharmacokinetic and pharmacodynamic genetic markers in pharmacogenetic EPS risk assessment.

No significant relationships.

Haloperidol is a high-potency first generation antipsychotic and one of the most frequently used antipsychotic medications. It is a potent central antagonist of type 2 dopamine receptors, with low alpha 1 adrenergic activity and has no antihistamine or anti-cholinergic activity. It is a widely used drug with proven efficacy. Angioedema is a very rare side effect, occurring in <1% of cases.

Case report and reflection on its etiology

A Pubmed search was performed with the MeSH terms “haloperidol” and “Anaphylactic reactions”. Relevant articles obtained from the respective bibliographic references were also consulted.

The following case describes the development of angioedema in a patient with an acute confusional syndrome on the second haloperidol IM administration for symptomatic control of agitation. Angioedema has been reported as an adverse effect of various antipsychotics such as clozapine, risperidone, ziprazidone and chlorpromazine, however, resulting from haloperidol administration is rare.

In long-term formulations sensitization testing is especially important but a single prior administration is not sufficient, a second controlled administration is essential to avoid this kind of fatal reactions.

From case reports, haloperidol administration has been associated with QTc prolongation, torsades de pointes, and sudden cardiac death. In a vulnerable population of critically ill patients after cardiac surgery, however, it is unclear whether haloperidol administration affects the QTc interval. Thus, the aim of this study is to explore the effect of haloperidol in low doses on this interval.

This retrospective cohort study was performed on a cardio-surgical intensive care unit (ICU), screened 2,216 patients and eventually included 68 patients with delirium managed with oral and intravenous haloperidol. In this retrospective analysis, electrocardiograms were taken prior and within 24 h after haloperidol administration. The effect of haloperidol on QTc was determined with a Person correlation, and inter-group differences were measured with new long QT comparisons.

In total, 68 patients were included, the median age was 71 (64–79) years and predominantly male (77%). Haloperidol administration followed ICU admission by three days and the cumulative dose was 4 (2–9) mg. As a result, haloperidol administration did not affect the QTc (r = 0.144, p = 0.23). In total, 31% (21/68 patients) had a long QT before and 27.9% (19/68 patients) after haloperidol administration. Only 12% (8/68 patients) developed a newly onset long QT. These patients were not different in the route of administration, cumulative haloperidol doses, comorbidities, laboratory findings, or medications.

These results indicated that low-dose intravenous haloperidol was safe and not clinically relevant for the development of a newly onset long QT syndrome or adverse outcomes and support recent findings inside and outside the ICU setting.

This Schizophrenia Outcome Survey compared medical costs, psychopathology and adverse events in outpatients for 2 years following hospitalisation for an acute schizophrenic episode.

Adults stabilised with haloperidol, olanzapine or risperidone entered this observational study ≤1 month after discharge and were assessed at baseline, 3, 6, 12, 18 and 24 months using Brief Psychiatric Rating Scale (BPRS), Clinical Global Impression (CGI), Global Assessment of Functioning and adverse events reporting.

Among 323 patients (haloperidol 32, olanzapine 149, risperidone 142), baseline characteristics were similar in the olanzapine and risperidone groups, except for more first episodes in the risperidone group (p = 0.01). Haloperidol patients were more often single and institutionalised, less educated, had more residual schizophrenia, were longer hospitalised in the previous year, took more corrective and psychotropic drugs and had more extrapyramidal symptoms (EPS) and gynaecomastia (all significantly). Sixty-eight percent of patients completed a 2-year follow-up. In all groups, CGI and GAF improved during the first 3 months (both p < 0.0001) while BPRS deteriorated in the first year (all within group changes p < 0.05, between group changes NS) before it stabilised. There were no significant differences in hospitalisations and no change in social profile. At the last visit, 66% of haloperidol (p < 0.01), 35% of olanzapine (NS) and 39% (NS) of risperidone patients had ≥1 EPS; 69% (p < 0.013), 40 and 44%, respectively, had ≥1 sexual problem (NS). Mean weight gain was 0.4 (NS), 2.6 (p < 0.05) and 2.6 kg (p < 0.05), respectively.

In this naturalistic study, treatment allocation might have introduced a bias in the interpretation of efficiency results, but olanzapine and risperidone caused less EPS than haloperidol during 2 years of outpatient follow-up.

• • Recognise the role of brain transmitter pathways leading to arousal and to agitation

• • Be aware of mechanisms of action of benzodiazepines, antipsychotics and antihistamines and distinguishing sedation from calming effects

• • Know the recommendations of NICE guidelines for rapid tranquillisation and the findings of the national POMH-UK audit and be able to contribute to local policies

None.

The brainstem-derived neuropeptide S (NPS) has a multidirectional regulatory activity, especially as a potent anxiolytic factor. Accumulating data suggests that neuroleptics affect peptidergic signalling in various brain structures. However, there is no information regarding the influence of haloperidol on NPS and NPS receptor (NPSR) expression.

We assessed NPS and NPSR mRNA levels in brains of rats treated with haloperidol using quantitative real-time polymerase chain reaction.

Chronic haloperidol treatment (4 weeks) led to a striking upregulation of NPS and NPSR expression in the rat brainstem. Conversely, the NPSR mRNA expression was decreased in the hippocampus and striatum.

This stark increase of NPS in response to haloperidol treatment supports the hypothesis that this neuropeptide is involved in the dopamine-dependent anxiolytic actions of neuroleptics and possibly also in the pathophysiology of mental disorders. Furthermore, our findings underline the complex nature of potential interactions between dopamine receptors and brain peptidergic pathways, which has potential clinical applications.

It has been reported that lithium may inhibit lipid peroxidation and protein oxidation. Lithium salts also appear to stimulate cell proliferation, increase neurogenesis, and delay cell death. Oxidative stress and neurodegeneration may play an important role in the pathophysiology of bipolar disorder and the disease course thereof. The aim of this research is to estimate the influence of lithium (alone and in combination with haloperidol) on the parameters of oxidative stress and viability of SH-SY5Y cell lines in neutral and pro-oxidative conditions.

The evaluated oxidative stress parameter was lipid peroxidation. The viability of the cell lines was measured utilising the MTT test.

In neutral conditions, higher levels of thiobarbituric acid reactive substances were observed in those samples which contained both haloperidol and lithium than in other samples. However, these differences were not statistically significant. Cell viability was significantly higher in therapeutic lithium samples than in the controls; samples of haloperidol alone as well as those of haloperidol with lithium did not differ from controls.

The results of our study may indicate that lithium possess neuroprotective properties that may be partly due to antioxidative effects. The combination of lithium and haloperidol may generate increased oxidative stress.