Co-producing Human and Animal Experimental Subjects: Exploring the Views of UK COVID-19 Vaccine Trial Participants on Animal Testing.

Preclinical (animal) testing and human testing of drugs and vaccines are rarely considered by social scientists side by side. Where this is done, it is typically for theoretically exploring the ethics of the two situations to compare relative treatment. In contrast, we empirically explore how human clinical trial participants understand the role of animal test subjects in vaccine development. Furthermore, social science research has only concentrated on broad public opinion and the views of patients about animal research, whereas we explore the views of a public group particularly implicated in pharmaceutical development: experimental subjects. We surveyed and interviewed COVID-19 vaccine trial participants in Oxford, UK, on their views about taking part in a vaccine trial and the role of animals in trials. We found that trial participants mirrored assumptions about legitimate reasons for animal testing embedded in regulation and provided insight into (i) the nuances of public opinion on animal research; (ii) the co-production of human and animal experimental subjects; (iii) how vaccine and medicine testing, and the motivations and demographics of clinical trial participants, change in an outbreak; and (iv) what public involvement can offer to science.

The effect of sodium-glucose co-transporter 2 inhibitors on outcomes after cardiac resynchronization therapy.

AIMS: The trials upon which recommendations for the use of cardiac resynchronization therapy (CRT) in heart failure used optimal medical therapy (OMT) before sodium-glucose co-transporter 2 inhibitors (SGLT2i). Moreover, the SGLT2i heart failure trials included only a small proportion of participants with CRT, and therefore, it remains uncertain whether SGLT2i should be considered part of OMT prior to CRT. METHODS AND RESULTS: We compared electrocardiogram (ECG) and echocardiographic responses to CRT as well as hospitalization and mortality rates in consecutive patients undergoing implantation at a large tertiary centre between January 2019 to June 2022 with and without SGLT2i treatment. Three hundred seventy-four participants were included aged 74.0 ± 11.5 years (mean ± standard deviation), with a left ventricular ejection fraction (LVEF) of 31.8 ± 9.9% and QRS duration of 161 ± 29 ms. The majority had non-ischaemic cardiomyopathy (58%) and were in NYHA Class II/III (83.6%). These characteristics were similar between patients with (n = 66) and without (n = 308) prior SGLT2i treatment. Both groups demonstrated similar evidence of response to CRT in terms of QRS duration shortening, and improvements in LVEF, left ventricular end-diastolic inner-dimension (LVIDd) and diastolic function (E/A and e/e'). While there was no difference in rates of hospitalization (for heart failure or overall), mortality was significantly lower in patients treated with SGLT2i compared with those who were not (6.5 vs. 16.6%, P = 0.049). CONCLUSIONS: We observed an improvement in mortality in patients undergoing CRT prescribed SGLT2i compared with those not prescribed SGLT2i, despite similar degrees of reverse remodelling. The authors recommend starting SGLT2i prior to CRT implantation, where it does not delay implantation.

Comparison of troponin and natriuretic peptides in Takotsubo syndrome and acute coronary syndrome: a meta-analysis.

OBJECTIVE: Takotsubo syndrome (TTS) is an acute heart failure syndrome which resembles acute coronary syndrome (ACS) at presentation. Differentiation requires coronary angiography, but where this does not occur immediately, cardiac biomarkers may provide additional utility. We performed a meta-analysis to compare troponin and natriuretic peptides (NPs) in TTS and ACS to determine if differences in biomarker profile can aid diagnosis. METHODS: We searched five literature databases for studies reporting NPs (Brain NP (BNP)/NT-pro-BNP) or troponin I/T in TTS and ACS, identifying 28 studies for troponin/NPs (5618 and 1145 patients, respectively). RESULTS: Troponin was significantly lower in TTS than ACS (standardised mean difference (SMD) -0.86; 95% CI, -1.08 to -0.64; p<0.00001), with an absolute difference of 75 times the upper limit of normal (×ULN) higher in ACS than TTS. Conversely, NPs were significantly higher in TTS (SMD 0.62; 95% CI, 0.44 to 0.80; p<0.00001) and 5.8×ULN greater absolutely. Area under the curve (AUC) for troponin in ACS versus TTS was 0.82 (95% CI, 0.70 to 0.93), and 0.92 (95% CI, 0.80 to 1.00) for ST-segment elevation myocardial infarction versus TTS. For NPs, AUC was 0.69 (95% CI, 0.48 to 0.89). Combination of troponin and NPs with logistic regression did not improve AUC. Recursive Partitioning and Regression Tree analysis calculated a troponin threshold ≥26×ULN that identified 95% cases as ACS where and specificity for ACS were 85.71% and 53.57%, respectively, with 94.32% positive predictive value and 29.40% negative predictive value. CONCLUSIONS: Troponin is lower and NPs higher in TTS versus ACS. Troponin had greater power than NPs at discriminating TTS and ACS, and with troponin ≥26×ULN patients are far more likely to have ACS.

Cardiovascular risk in a contemporary cohort of patients with myeloproliferative neoplasms'.

BACKGROUND: Myeloproliferative neoplasms (MPNs) are a group of disorders of clonal haemopoiesis associated with an inherent risk of arterial and venous thrombotic complications. The prevalence of thrombotic complications and the impact of cardiovascular risk factors (CVRFs) in contemporary patient cohorts within the current era of MPN treatments have not been completely defined. OBJECTIVES: We aim to characterise the cardiovascular risk of patients with MPN by identifying the prevalence of CVRFs and describing the pattern of thrombotic events. We also aim to utilise the QRISK3 algorithm, which is a validated model used to estimate an individual's risk of developing cardiovascular disease, to further phenotype this cohort of patients. METHODS: We perform a retrospective analysis on a single-centre cohort of 438 patients with MPN. RESULTS: MPN patients continue to carry a high burden of vascular morbidity with a prevalence of arterial thrombotic events in 15.8 % (69/438) and venous thrombotic events in 13.2 % (58/438) of the cohort. The novel use of the QRISK3 algorithm, which showed a mean score of 13.7 % across the MPN population, provides further evidence to suggest an increased cardiovascular risk in MPN patients. CONCLUSION: With an increased risk of cardiovascular disease in patients with MPN, we propose an integrated approach between primary and specialised healthcare services using risk stratification tools such as QRISK3, which will allow aggressive optimisation of CVRFs to prevent thrombosis and reduce the overall morbidity and mortality in patients with MPN.

Lifestyle advice for hypertension or diabetes: trend analysis from 2002 to 2017 in England.

BACKGROUND: Guidelines recommend that GPs give patients lifestyle advice to manage hypertension and diabetes. Increasing evidence shows that this is an effective and practical treatment for these conditions, but it is unclear whether GPs offer this support. AIM: To investigate trends in the percentage of patients with hypertension/diabetes receiving lifestyle advice versus medication. DESIGN AND SETTING: This was a trend analysis of self-reported data from the annual Health Survey for England (HSE) (2003-2017) and GP-recorded data from the QResearch database (2002-2016). METHOD: The percentage of patients with hypertension or diabetes who received lifestyle advice or medication was calculated in each year. Associations between likelihood of receiving lifestyle advice and characteristics were assessed using multivariable logistic regression. RESULTS: The percentage of patients receiving lifestyle advice was consistently lower than those receiving medication in both self-reported and medical records. There was consistent evidence of increasing trends in the percentage of patients with hypertension receiving lifestyle advice (HSE 13.8% to 20.1%; Ptrend <0.001; QResearch 11.0% to 22.7%; Ptrend <0.001). For diabetes, there was a non-significant decline in self-reported receipt of lifestyle advice (45.0% to 27.9%; Ptrend = 0.111) and a significant increase in medically recorded delivery of this advice (20.7% to 40.5%; Ptrend <0.001). Patients with hypertension who were overweight or obese were more likely to receive lifestyle advice than those of a healthy weight, whereas the opposite was true for diabetes. CONCLUSION: Only a minority of patients with diabetes or hypertension report receiving lifestyle advice or have this recorded in their medical records. Interventions beyond guidelines are needed to increase the delivery of behavioural interventions to treat these conditions.

What proportion of people have a follow-up biopsy in randomized trials of treatments for non-alcoholic steatohepatitis?: A systematic review and meta-analysis.

BACKGROUND AND AIM: Trials of treatments for non-alcoholic steatohepatitis require endpoint assessment with liver biopsies. Previous large-scale trials have calculated their sample size expecting high retention but on average did not achieve this. We aimed to quantify the proportion of participants with a valid follow-up biopsy. METHODS: We conducted a systematic review of MEDLINE and Embase until May 2020 and included randomized clinical trials of any intervention in non-alcoholic steatohepatitis with at least 1-year follow-up. We were guided by Cochrane methods to run a meta-analysis with generalized linear mixed models with random effects. RESULTS: Forty-one trials (n = 6,695) were included. The proportion of participants with a valid follow-up biopsy was 82% (95%CI: 78%-86%, I2 = 92%). There was no evidence of a difference by location, trial length, or by allocated treatment group. Reasons for missing follow-up biopsies were, in ranked order, related to participants (95 per 1,000 participants (95%CI: 69-129, I2 = 92%), medical factors, protocol, trial conduct, and other/unclear. Biopsy-related serious adverse events occurred in 16 per 1,000 participants (95% CI: 8-33, I2 = 54%). No biopsy-related deaths were reported. CONCLUSIONS: The proportion of participants with a valid follow-up biopsy in therapeutic trials in non-alcoholic steatohepatitis is on average 82%, with around 1 in 10 participants declining a follow-up biopsy. These findings can inform adequately-powered trials.

The effect of the magnitude of weight loss on non-alcoholic fatty liver disease: A systematic review and meta-analysis.

BACKGROUND: Trials show that weight loss interventions improve biomarkers of non-alcoholic fatty liver disease (NAFLD), but it is unclear if a dose-response relationship exists. OBJECTIVE: We aimed to quantify the dose-response relationship between the magnitude of weight loss and improvements in NAFLD. METHODS: Nine databases and trial registries were searched until October 2020. Single-arm, non-randomized comparative, or randomized trials of weight loss interventions (behavioral weight loss programs [BWLPs], pharmacotherapy, or bariatric surgery) in people with NAFLD were eligible for inclusion if they reported an association between changes in weight and changes in blood, radiological, or histological biomarkers of liver disease. The review followed Cochrane methods and the risk of bias was assessed using the Newcastle-Ottawa scale. Pooled unstandardized b coefficients were calculated using random-effect meta-analyses. RESULTS: Forty-three studies (BWMPs: 26, pharmacotherapy: 9, surgery: 8) with 2809 participants were included. The median follow-up was 6 (interquartile range: 6) months. The direction of effect was generally consistent but the estimates imprecise. Every 1 kg of weight lost was associated with a 0.83-unit (95% CI: 0.53 to 1.14, p < 0.0001, I2 = 92%, n = 18) reduction in alanine aminotransferase (U/L), a 0.56-unit (95% CI: 0.32 to 0.79, p < 0.0001, I2 = 68%, n = 11) reduction in aspartate transaminase (U/L), and a 0.77 percentage point (95% CI: 0.51 to 1.03, p < 0.0001, I2 = 72%, n = 11) reduction in steatosis assessed by radiology or histology. There was evidence of a dose-response relationship with liver inflammation, ballooning, and resolution of NAFLD or NASH, but limited evidence of a dose-response relationship with fibrosis or NAFLD activity score. On average, the risk of bias for selection and outcome was medium and low, respectively. CONCLUSION: Clinically significant improvements in NAFLD are achieved even with modest weight loss, but greater weight loss is associated with greater improvements. Embedding support for formal weight loss programs as part of the care pathway for the treatment of NAFLD could reduce the burden of disease. PROSPERO: CRD42018093676.

Early detection of doxorubicin-induced cardiotoxicity in rats by its cardiac metabolic signature assessed with hyperpolarized MRI.

Doxorubicin (DOX) is a widely used chemotherapeutic agent that can cause serious cardiotoxic side effects culminating in congestive heart failure (HF). There are currently no clinical imaging techniques or biomarkers available to detect DOX-cardiotoxicity before functional decline. Mitochondrial dysfunction is thought to be a key factor driving functional decline, though real-time metabolic fluxes have never been assessed in DOX-cardiotoxicity. Hyperpolarized magnetic resonance imaging (MRI) can assess real-time metabolic fluxes in vivo. Here we show that cardiac functional decline in a clinically relevant rat-model of DOX-HF is preceded by a change in oxidative mitochondrial carbohydrate metabolism, measured by hyperpolarized MRI. The decreased metabolic fluxes were predominantly due to mitochondrial loss and additional mitochondrial dysfunction, and not, as widely assumed hitherto, to oxidative stress. Since hyperpolarized MRI has been successfully translated into clinical trials this opens up the potential to test cancer patients receiving DOX for early signs of cardiotoxicity.

Why do medical graduates choose rural careers?

INTRODUCTION: This study is based on the metaphor of the 'rural pipeline' into medical practice. The four stages of the rural pipeline are: (1) contact between rural secondary schools and the medical profession; (2) selection of rural students into medical programs; (3) rural exposure during medical training; and (4) measures to address retention of the rural medical workforce. METHODS: Using the rural pipeline template we conducted a literature review, analysed the selection methods of Australian graduate entry medical schools and interviewed 17 interns about their medical career aspirations. LITERATURE REVIEW: The literature was reviewed to assess the effectiveness of selection practices to predict successful gradation and the impact of rural pipeline components on eventual rural practice. Undergraduate academic performance is the strongest predictor of medical course academic performance. The predictive power of interviews is modest. There are limited data on the predictive power of other measures of non-cognitive performance or the content of the undergraduate degree. Prior rural residence is the strongest predictor of choice of a rural career but extended rural exposure during medical training also has a significant impact. The most significant influencing factors are: professional support at national, state and local levels; career pathway opportunities; contentedness of the practitioner's spouse in rural communities; preparedness to adopt a rural lifestyle; educational opportunities for children; and proximity to extended family and social circle. Analysis of selection methods: Staff involved in student selection into 9 Australian graduate entry medical schools were interviewed. Four themes were identified: (1) rurality as a factor in student selection; (2) rurality as a factor in student selection interviews; (3) rural representation on student selection interview panels; (4) rural experience during the medical course. Interns' career intentions: Three themes were identified: (1) the efficacy of the rural pipeline; (2) community connectedness through the rural pipeline; (3) impediments to the effect of the rural pipeline, the most significant being a partner who was not committed to rural life CONCLUSION: Based on the literature review and interviews, 11 strategies are suggested to increase the number of graduates choosing a career in rural medicine, and one strategy for maintaining practitioners in rural health settings after graduation.

Association of Weight Loss Interventions With Changes in Biomarkers of Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis.

IMPORTANCE: Nonalcoholic fatty liver disease (NAFLD) affects about 25% of adults worldwide and is associated with obesity. Weight loss may improve biomarkers of liver disease, but its implications have not been systematically reviewed and quantified. OBJECTIVE: To estimate the association of weight loss interventions with biomarkers of liver disease in NAFLD. DATA SOURCES: MEDLINE, Embase, PsycINFO, CINAHL, Cochrane, and Web of Science databases along with 3 trial registries were searched from inception through January 2019. STUDY SELECTION: Randomized clinical trials of people with NAFLD were included if they compared any intervention aiming to reduce weight (behavioral weight loss programs [BWLPs], pharmacotherapy, and surgical procedures) with no or lower-intensity weight loss intervention. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers screened the studies, extracted the data, and assessed the risk of bias using the Cochrane tool. Pooled mean differences or odds ratios (ORs) were obtained from random-effects meta-analyses. MAIN OUTCOMES AND MEASURES: Blood, radiologic, and histologic biomarkers of liver disease. RESULTS: Twenty-two studies with 2588 participants (with a mean [SD] age of 45 [14] years and with approximately 66% male) were included. Fifteen studies tested BWLPs, 6 tested pharmacotherapy, and 1 tested a surgical procedure. The median (interquartile range) intervention duration was 6 (3-8) months. Compared with no or lower-intensity weight loss interventions, more-intensive weight loss interventions were statistically significantly associated with greater weight change (-3.61 kg; 95% CI, -5.11 to -2.12; I2 = 95%). Weight loss interventions were statistically significantly associated with improvements in biomarkers, including alanine aminotransferase (-9.81 U/L; 95% CI, -13.12 to -6.50; I2 = 97%), histologically or radiologically measured liver steatosis (standardized mean difference: -1.48; 95% CI, -2.27 to -0.70; I2 = 94%), histologic NAFLD activity score (-0.92; 95% CI, -1.75 to -0.09; I2 = 95%), and presence of nonalcoholic steatohepatitis (OR, 0.14; 95% CI, 0.04-0.49; I2 = 0%). No statistically significant change in histologic liver fibrosis was found (-0.13; 95% CI, -0.54 to 0.27; I2 = 68%). Twelve studies were at high risk of bias in at least 1 domain. In a sensitivity analysis of the 3 trials at low risk of bias, the estimates and precision of most outcomes did not materially change. CONCLUSIONS AND RELEVANCE: The trials, despite some heterogeneity, consistently showed evidence of the association between weight loss interventions and improved biomarkers of liver disease in NAFLD in the short to medium term, although evidence on long-term health outcomes was limited. These findings appear to support the need to change the clinical guidelines and to recommend formal weight loss programs for people with NAFLD.

Clinical review: Major consequences of illicit drug consumption.

Because illicit drugs are now widely consumed, every doctor needs to know their acute medical consequences and complications. Here, we review the problems associated with the different drugs from a systems-based viewpoint. Apart from the respiratory depressant effect of opioids, crack cocaine is the most common cause of respiratory complications, mainly linked with its mode of use, with airway burns, pneumothorax, pneumomediastinum, and lung syndromes being well-recognised sequelae. Because of its marked cardiovascular effects, cocaine is also a major cause of coronary syndromes and myocardial infarction. Amphetamines may produce similar effects less commonly. Hyperthermia may occur with cocaine toxicity or with 3,4-methylenedioxymethamphetamine (MDMA) due to exertion or from serotonin syndrome. Cerebral haemorrhage may result from the use of amphetamines or cocaine. Hallucinations may follow consumption of LSD, amphetamines, or cocaine. MDMA is a major cause of acute severe hyponatraemia and also has been linked with hepatic syndromes. Collapse, convulsions, or coma may be caused in different circumstances by opioids, MDMA, or gamma hydroxybutyrate and may be aggravated by other sedatives, especially alcohol and benzodiazepines. Recognition of these acute complications is urgent, and treatment must be based on an understanding of the likely underlying problem as well as on basic principles of supportive care.

Cardiac applications of hyperpolarised magnetic resonance.

Cardiovascular disease is the leading cause of death world-wide. It is increasingly recognised that cardiac pathologies show, or may even be caused by, changes in metabolism, leading to impaired cardiac energetics. The heart turns over 15 times its own weight in ATP every day and thus relies heavily on the availability of substrates and on efficient oxidation to generate this ATP. A number of old and emerging drugs that target different aspects of metabolism are showing promising results with regard to improved cardiac outcomes in patients. A non-invasive imaging technique that could assess the role of different aspects of metabolism in heart disease, as well as measure changes in cardiac energetics due to treatment, would be valuable in the routine clinical care of cardiac patients. Hyperpolarised magnetic resonance spectroscopy and imaging have revolutionised metabolic imaging, allowing real-time metabolic flux assessment in vivo for the first time. In this review we summarise metabolism in the healthy and diseased heart, give an introduction to the hyperpolarisation technique, 'dynamic nuclear polarisation' (DNP), and review the preclinical studies that have thus far explored healthy cardiac metabolism and different models of human heart disease. We furthermore show what advances have been made to translate this technique into the clinic, what technical challenges still remain and what unmet clinical needs and unexplored metabolic substrates still need to be assessed by researchers in this exciting and fast-moving field.

Cost-effectiveness of screening and referral to an alcohol health worker in alcohol misusing patients attending an accident and emergency department: a decision-making approach.

We present the cost and cost-effectiveness of referral to an alcohol health worker (AHW) and information only control in alcohol misusing patients. The study was a pragmatic randomised controlled trial conducted from April 2001 to March 2003 in an accident and emergency department (AED) in a general hospital in London, England. A total of 599 adults identified as drinking hazardously according to the Paddington Alcohol Test were randomised to referral to an alcohol health worker who delivered a brief intervention (n = 287) or to an information only control (n = 312). Total societal costs, including health and social services costs, criminal justice costs and productivity losses, and clinical measures of alcohol consumption were measured. Levels of drinking were observably lower in those referred to an AHW at 12 months follow-up and statistically significantly lower at 6 months follow-up. Total costs were not significantly different at either follow-up. Referral to AHWs in an AED produces favourable clinical outcomes and does not generate a significant increase in cost. A decision-making approach revealed that there is at least a 65% probability that referral to an AHW is more cost-effective than the information only control in reducing alcohol consumption among AED attendees with a hazardous level of drinking.

Alpha 1-acid glycoprotein reverses cocaine-induced sodium channel blockade in cardiac myocytes.

UNLABELLED: Alpha 1-acid glycoprotein (AAG) is an acute phase protein capable of binding basic drugs. This action explains its reversal of sodium channel blockade by drugs such as amitriptyline and quinidine. We report here the reversal of cocaine-induced sodium channel blockade by AAG. The sodium channel blocking property of cocaine is a major mechanism behind cocaine-induced sudden cardiac death, since sodium channels play a key role in the initiation and regulation of the heart beat. Voltage-gated sodium current (I(Na)) was recorded using whole-cell patch-clamp techniques. Guinea-pig cardiac ventricular myocytes were isolated and continuously perfused at room temperature with physiological solutions. At concentrations ranging from 5 to 320 microM cocaine showed a dose-dependent and reversible blockade of I(Na) with an IC50 of 45.9 microM. The addition of equimolar amounts of AAG to cocaine produced almost complete reversal of cocaine's effects, suggesting a single binding site for cocaine on the AAG molecule. With changes of peak I(Na) normalized against control as 1, cocaine at 20 and 40 microM reduced I(Na) to 0.62+/-0.042 (n = 6) and 0.57+/-0.052 (n = 9), respectively, and the addition of an equimolar concentration of AAG reversed I(Na) to 0.86+/-0.022 and 0.91+/-0.060, respectively. IN CONCLUSION: AAG reverses cocaine-induced sodium channel blockade in a dose-dependent manner, indicating a therapeutic potential to reverse acute cocaine cardiac toxicity.

Screening and referral for brief intervention of alcohol-misusing patients in an emergency department: a pragmatic randomised controlled trial.

BACKGROUND: Alcohol misuse is highly prevalent among people attending emergency departments, but the effect of intervention by staff working in these departments is unclear. We investigated the effect of screening and referral of patients found to be misusing alcohol while attending an emergency department. METHODS: We undertook a single-blind pragmatic randomised controlled trial. Patients received either an information leaflet or an information leaflet plus an appointment with an alcohol health worker. Outcome data were collected by patient interview and examination of hospital records at 6 and 12 months. FINDINGS: 599 patients were randomised over a 12-month period. At 6 months, those referred to an alcohol health worker were consuming a mean of 59.7 units of alcohol per week compared with 83.1 units in the control group (t -2.4, p=0.02). At 12 months those referred were drinking 57.2 units per week compared with 70.8 in controls (t -1.7, p=0.09). Those referred to the alcohol health worker had a mean of 0.5 fewer visits to the emergency department over the following 12 months (1.2 compared with 1.7, t -2.0, p=0.046). Differences in quality of life were not found. INTERPRETATION: Opportunistic identification and referral for alcohol misuse in an emergency department is feasible, associated with lower levels of alcohol consumption over the following 6 months, and reduces reattendance at the department. Short-term reductions in alcohol consumption associated with referral for brief intervention for alcohol misuse benefit patients and reduce demand for accident and emergency department services.

Cannabis as a precipitant of cardiovascular emergencies.

Cannabis smoking is on the increase both in the United Kingdom and in the United States. For over three decades it has been known that cannabis has pathophysiological effects on the cardiovascular system, and previously an association with an increased risk of myocardial infarction has been reported. However, it is not yet known whether cannabis contributes directly to coronary artery disease. We describe two distinct cases; in the first cannabis use precipitated a malignant arrhythmia in a patient with critical ischaemia from longstanding coronary artery disease. In the second, a young patient presented with an acute myocardial infarction that had started whilst smoking marijuana; subsequently diffuse coronary artery disease was found at angiography despite the patient's low risk factor status. Patients who are known cannabis smokers and who have cardiovascular disease should be warned that it is likely to aggravate coronary ischaemia, and may even trigger myocardial infarction.

Overdose profiles of new antipsychotic agents.

Although the more recently introduced antipsychotic drugs are increasing in popularity, the pattern of symptomatology when taken in overdose is not well defined. We monitored all enquiries to the National Poisons Information Service, London (NPIS, London) concerning antipsychotic drugs over a 9-month period in 1997 and report our findings concerning four drugs (olanzapine, clozapine, risperidone and sulpiride). All overdoses involving a single agent were followed up by a letter to the enquirer requesting details and outcome of the case. Although a total of 574 enquiries involving the selected antipsychotic drugs were received, only 45 of these cases involved overdose with a single agent. There were no fatalities or cases of convulsions in the series. Cardiac arrhythmias were only noted with sulpiride. Symptoms were most marked with clozapine, with a majority of patients experiencing agitation, dystonia, central nervous system (CNS) depression and tachycardia. Olanzapine and sulpiride produced a range of different symptoms, while most patients who had taken risperidone were asymptomatic. Monitoring poisons centre enquiries is a useful way of comparing overdose toxicities. We conclude that at least two of the novel antipsychotic agents, olanzapine and risperidone, appear to have a favourable overdose profile, which suggests that they are safer in overdose than the phenothiazines and butyrophenones.