Fatal poisoning with antipsychotic drugs, England and Wales 1993-2002

Acute Quetiapine Intoxication: Relationship Between Ingested Dose, Serum Concentration and Clinical Presentation-Structured Literature Review and Analysis

Over the past decade, quetiapine has become one of the most commonly used psychotropic drugs in acute intoxication events worldwide. A structured literature review and analysis were conducted to assess the relationship between the kinetic and dynamic profiles in acute quetiapine intoxication. The correlation between dose and peak serum concentration (cmax) was determined using Pearson's correlation coefficient. Binary logistic regression was used to evaluate dose and cmax as predictors of the most common clinical events, signs and symptoms. One hundred and thirty-four cases of acute quetiapine ingestion were included in the analysis, with a median ingested dose of 10 g and a median cmax of 4 mg/L. The typical half-life was estimated to be 16.5 h, significantly longer than at therapeutic doses. For the immediate-release formulation, a biphasic disposition could not be excluded. Dose and cmax demonstrated a weak but significant correlation (r = 0.256; N = 63; p = 0.043). Central nervous system depression and tachycardia were the most common clinical signs. Higher doses and concentrations increased the risk of severe intoxication and were good predictors of intubation, tachycardia, hypotension, QTc prolongation and seizures, but not QRS prolongation, arrhythmia, heart block, hypokalaemia or acidosis. The thresholds for dose and cmax that increased the risk for individual signs and symptoms varied widely. However, doses > 3 g or cmax > 2 mg/L can be considered as alert levels that represent a high risk for severe clinical course of acute quetiapine intoxication.

Antipsychotics as a method of suicide: population based follow-up study of suicide in Northern Finland

AIM

This study examined the trend and role of antipsychotics as a method of self-poisoning suicide.

MATERIALS AND METHODS

The basic data covered 483 poisoning suicides, occurring between the years 1988 and 2011, in Northern Finland, of which 178 (115 men, 63 women) were completed using antipsychotics.

RESULTS

During the 23-year follow-up period, second-generation antipsychotics (SGAs) overtook first-generation antipsychotics (FGAs) as a suicide method. Female victims, compared to males, had more commonly used quetiapine (17.5% vs. 6.1%, p = .016), while suicides using promazine were more common in males compared to females (36.5% vs. 22.2%, p = .049). People with unipolar depression had more frequently used SGAs (40.0%) or a combination of SGAs and FGAs (12.5%) than FGAs (19.2%) (p = .019) in their suicides.

CONCLUSION

The use of SGAs in suicides is becoming increasingly common, which calls for further studies.

The relative lethal toxicity of pharmaceutical and illicit substances: A 16-year study of the Greater Newcastle Hunter Area, Australia

AIMS

We aim to calculate 2 metrics of relative lethal toxicity; the fatal toxicity index (FTI; number of deaths per year of a daily dose) and the case fatality (CF; number of deaths per overdose) with a focus on opioids, antidepressants, antipsychotics, benzodiazepines and illicit drugs.

METHODS

This descriptive cohort study used the Australian National Coronial Information System (NCIS) to identify a population of individuals with drug-associated deaths in the Greater Newcastle Hunter Area between January 2002 and December 2016. This was combined with Australian medicine dispensing data and corresponding data from the Hunter Area Toxicology Service to calculate FTI and CF.

RESULTS

There were 444 drug-related deaths and 21,296 overdoses during the study period. FTI and CF were well correlated (Spearman's rho 0.64, P < .001). Of the classes of interest, opioids had the highest FTI (40.3 95% confidence interval [CI] 35.2-45.4 deaths per 100 years of use at the defined daily dose or deaths/DDD/100 years) and CF (12.4% 95%CI 11.0-13.9). Fentanyl, methadone and morphine had the highest relative fatal toxicity within this class. Tricyclic antidepressants had the highest relative fatal toxicity of all antidepressants (FTI 14.5 95%CI 9.7-19.3 deaths/DDD/100 years and CF 7.1% [95%CI 4.8-9.3]) and benzodiazepines appeared to be more associated with multiple agent deaths than single. Of the illicit drugs, heroin had the highest CF (26.4%, 95%CI 19.1-33.7).

CONCLUSION

Knowledge of relative lethal toxicity is useful to prescribers and medicines and public health policy makers in restricting access to more toxic drugs and may also assist coroners in determining cause of death.

Extended-release quetiapine overdose is associated with delayed onset of toxicity compared to immediate-release quetiapine overdose

OBJECTIVES

There are currently no studies comparing toxicity after extended-release (XR) and immediate-release (IR) quetiapine overdose. To compare the time course of toxicity of XR and IR quetiapine overdose.

METHODS

Retrospective analysis of toxicology unit consultations from July 2013 to April 2016. Information extracted included demographics, type of ingestion (IR, XR, mixed formulation, dose, tablet count, time to presentation, sedative co-ingestants), lowest Glasgow coma score (GCS), time to lowest GCS, fastest pulse, lowest systolic blood pressure, and time to recovery from sedation.

RESULTS

There were 256 presentations in 210 patients. Females 86% (n = 181), median age 30.5 years (IQR 23-43). Median quetiapine dose for the whole cohort was 2 g (IQR 1-5). Sedating co-ingestants were seen in 61% of presentations. Comparison of IR (n = 43) and XR quetiapine (n = 23) ingestions without sedating co-ingestants revealed a larger median ingested dose for XR formulation: 5.7 g versus 1.75 g (P = 0.004) and larger median tablet strength (XR 200 mg vs IR 100 mg, P < 0.001). Median time to lowest GCS: XR 7 h (IQR 4.9-11) versus IR 3.8 h (IQR 2.4-5.7), P < 0.001. Median time to peak pulse: XR 9 h (IQR 3-12) versus IR 2.5 h (IQR 1.5-5), P = 0.01. Median time to recovery from sedation: XR quetiapine 20 h (IQR 12-39) versus 12 h (IQR 5.5-22), P < 0.05. Median duration of intubation: XR 47 h versus 17 h for IR, P = 0.04).

CONCLUSION

XR quetiapine overdoses without sedating co-ingestants were associated with a doubling of time to peak sedation and pulse, and had longer recovery from sedation. The absence of sedation or tachycardia 12 h post-overdose of XR quetiapine seems a reasonable timeframe to rule out significant poisoning.

Sudden cardiac death and antipsychotics Part 2: Monitoring and prevention

Cardiac safety of antipsychotic drugs continues to be a concern for both typical and atypical antipsychotics. Risk appears greatest in those with pre-existing cardiac disease but many patients may have occult cardiovascular disease. In addition, several drugs appear to increase the likelihood of diabetes and weight gain, which may have an additive adverse effect. On the basis of risk of sudden cardiac death and risk of QTc prolongation we suggest considering antipsychotics in two categories – higher and lower risk. Of most concern is the use of large cumulative doses of antipsychotics that are sometimes given inadvertently by different prescribers. Clinicians need to be aware how to read an ECG, and how to monitor physical parameters and interpret the significance of QTc prolongation in relation to antipsychotic prescribing. We suggest provisional guidance on antipsychotic monitoring in relation to cardiac safety but acknowledge that future studies will help clarify which antipsychotic drugs and which concomitant risk factors are most important for those with and without established cardiac disease.

Antipsychotic-related fatal poisoning, England and Wales, 1993-2013: impact of the withdrawal of thioridazine

CONTEXT

Use of second generation antipsychotics in England and Wales has increased in recent years whilst prescription of first generation antipsychotics has decreased.

METHODS

To evaluate the impact of this change and of the withdrawal of thioridazine in 2000 on antipsychotic-related fatal poisoning, we reviewed all such deaths in England and Wales 1993-2013 recorded on the Office for National Statistics drug poisoning deaths database. We also reviewed antipsychotic prescribing in the community, England and Wales, 2001-2013. Use of routine mortality data: When an antipsychotic was recorded with other drug(s), the death certificate does not normally say if the antipsychotic caused the death rather than the other substance(s). A second consideration concerns intent. A record of "undetermined intent" is likely to have been intentional self-poisoning, the evidence being insufficient to be certain that the individual intended to kill. A record of drug abuse/dependence, on the other hand, is likely to have been associated with an unintentional death. Accuracy of the diagnosis of poisoning: When investigating a death in someone prescribed antipsychotics, toxicological analysis of biological samples collected post-mortem is usually performed. However, prolonged attempts at resuscitation, or diffusion from tissues into blood as autolysis proceeds, may serve to alter the composition of blood sampled after death from that circulating at death. With chlorpromazine and with olanzapine a further factor is that these compounds are notoriously unstable in post-mortem blood. Deaths from antipsychotics: There were 1544 antipsychotic-related poisoning deaths. Deaths in males (N = 948) were almost twice those in females. For most antipsychotics, the proportion of deaths in which a specific antipsychotic featured either alone, or only with alcohol was 30-40%, but for clozapine (193 deaths) such mentions totalled 66%. For clozapine, the proportion of deaths attributed to either intentional self-harm, or undetermined intent was 44%, but for all other drugs except haloperidol (20 deaths) the proportion was 56% or more. The annual number of antipsychotic-related deaths increased from some 55 per year (1.0 per million population) between 1993 and 1998 to 74 (1.5 per million population) in 2000, and then after falling slightly in 2002 increased steadily to reach 109 (1.9 per million population) in 2013. Intent: The annual number of intentional and unascertained intent poisoning deaths remained relatively constant throughout the study period (1993: 35 deaths, 2013: 38 deaths) hence the increase in antipsychotic-related deaths since 2002 was almost entirely in unintentional poisoning involving second generation antipsychotics. Clozapine, olanzapine, and quetiapine were the second generation antipsychotics mentioned most frequently in unintentional poisonings (99, 136, and 99 deaths, respectively). Mentions of diamorphine/morphine and methadone (67 and 99 deaths, respectively) together with an antipsychotic were mainly (84 and 90%, respectively) in either unintentional or drug abuse-related deaths. Deaths and community prescriptions: Deaths involving antipsychotics (10 or more deaths) were in the range 11.3-17.1 deaths per million community prescriptions in England and Wales, 2001-2013. Almost all (96%) such deaths now involve second generation antipsychotics. This is keeping with the increase in annual numbers of prescriptions of these drugs overall (<1 million in 2000, 7 million in 2013), largely driven by increases in prescriptions for olanzapine and quetiapine. In contrast, deaths involving thioridazine declined markedly (from 40 in 2000 to 10 in 2003-2013) in line with the fall in prescriptions for thioridazine from 2001.

CONCLUSIONS

The removal of thioridazine has had no apparent effect on the incidence of antipsychotic-related fatal poisoning in England and Wales. That such deaths have increased steadily since 2001 is in large part attributable to an increase in unintentional deaths related to (i) clozapine, and (ii) co-exposure to opioids, principally diamorphine and methadone.

Fatal toxicity index of medicinal drugs based on a comprehensive toxicology database

The fatal toxicity index (FTI) is the absolute number of fatal poisonings caused by a particular drug divided by its consumption figure. Consequently, it is a useful measure in evaluating toxicity of the drug and its relevance in fatal poisonings. In this study, we assessed the FTI of medicinal drugs in 3 years (2005, 2009, and 2013) in Finland. As the measure of drug consumption, we used the number of defined daily doses (DDD) per population in each year. There were 70 medicinal drugs in Finland for which the mean FTI expressed as the number of deaths per million DDD over the three study years was higher or equal to 0.1. The Anatomical Therapeutic Chemical (ATC) classification system was used for the classification of the active ingredients of medicinal drugs according to the organ or system which they act on. Of these 70 drugs, 55 drugs (78.6 %) acted on the nervous system (denoted by ATC code N), 11 (15.7 %) on the cardiovascular system (C), three (4.3 %) on the alimentary tract and metabolism (A), and one (1.4 %) on the musculoskeletal system (M). The nervous system drugs consisted of 20 psycholeptics, (ATC code N05), 20 psychoanaleptics (N06), eight analgesics (N02), six antiepileptics (N03), and one other nervous system drug (N07). The highest individual FTIs were associated with the opioids methadone, dextropropoxyphene, oxycodone, tramadol, and morphine; the antipsychotics levomepromazine and chlorprothixene; and the antidepressants doxepin, amitriptyline, trimipramine, and bupropion. Buprenorphine was not included in the study, because most of the fatal buprenorphine poisonings were due to smuggled tablets. A clearly increasing trend in FTI was observed with pregabalin and possibly with bupropion, both drugs emerging as abused substances.

Coma After Quetiapine Fumarate Intentional Overdose in a 71-year-old Man: A Case Report

A 71-year-old man developed coma with severe respiratory failure, hypotension, and tachycardia induced by the intentional ingestion of quetiapine fumarate extended release (XR) 20 g. At the time, he had been treated for bipolar depression with venlafaxine 75 mg/day, lamotrigine 100 mg/day, pregabalin 75 mg/day, and quetiapine XR 400 mg/day for approximately 1 year. Comorbidities were hypertension treated with metoprolol, diabetes mellitus type 2 treated with metformin, and benign prostatic hyperplasia treated with silodosin. In the emergency room, about 4 h after ingestion of quetiapine fumarate XR, the presenting symptomatology was characterized by coma (Glasgow Coma Scale score 3), hypotension (blood pressure [BP] 90/60 mmHg), tachycardia (electrocardiogram [ECG] showed sinus tachycardia with heart rate 120 beats per minute and a QTc of 499 ms). A gastric lavage was performed and activated charcoal 50 g and magnesium sulfate 30 g was administered. About 6 h after ingestion, he developed marked desaturation and underwent mechanical ventilation; 13 h after ingestion, a severe hypotensive episode followed (BP 70/40), which was treated with an infusion of ringer lactate 500 cc. On the 3rd day after intentional overdose, an episode of agitation occurred; 4 days after ingestion, the quetiapine plasma level was found to be 42 ng/ml (within therapeutic range). At 5 days after ingestion, the patient developed septicemia caused by staphylococci (probably originating from the central vein catheter), which was treated with antibiotic therapy. On days 10 and 18 after the suicide attempt, two episodes of paroxysmal supraventricular tachycardia (PSVT) occurred and were successfully treated with intravenous adenosine triphosphate. The patient recovered completely without residual symptoms. In line with literature data, in this case report, symptoms of quetiapine overdose were tachycardia, agitation, hypotension, QT interval prolongation, and coma. A causal relationship between PSVT and quetiapine intoxication seems quite unlikely due to the drug level.

Suicidal behaviours during treatment for first-episode psychosis: towards a comprehensive approach to service-based prevention

AIM

Suicidal behaviours (suicide attempts and suicides) are common among individuals experiencing, or having recently experienced, a first-episode psychosis (FEP). Current interventions for suicidal behaviours are crisis driven and focused on hospital admission of patients at imminent risk of ending their lives. This paper aims to describe ideas for universal, selective and indicated strategies that may complement existing practices to suicide risk management in first-episode patients.

METHODS

Key findings from the Suicidal Behaviours in FEP Project were used to develop suggested interventions. The project examined the temporal course of suicide risk, common characteristics of suicidal behaviours and predictors of suicidal behaviours in 699 patients with FEP.

RESULTS

Key findings included: (i) 12% of FEP cohort engaged in suicidal behaviours during treatment (up to 3 years); (ii) first month of treatment conferred the highest suicide risk; (iii) 64% of suicidal behaviours were overdoses, usually on antipsychotics; (iv) 20% of suicidal behaviours occurred on psychiatric units and all involved hanging/strangulation; (v) most suicidal behaviours were impulsive, precipitated by psychosocial stressors and with serious intent; and (vi) proximal non-suicidal self-injurious behaviour and proximal negative life events were the strongest predictors.

CONCLUSION

Comprehensive approach by mental health services to prevention of suicidal behaviours among first-episode patients could be facilitated by: delineating safe quantities of prescribed medications available to outpatients; regular audits of fixtures on inpatient units; enhancing risk recognition by family members; routinely monitoring suicide risk levels; developing crisis cards with all new FEP patients to facilitate help seeking during distress; and skills training programs targeting distress tolerance, interpersonal effectiveness and problem-solving.

Evaluating the effects and safety of intravenous lipid emulsion on haloperidol-induced neurotoxicity in rabbit

There are many reports on the effect of intravenous lipid emulsion (ILE) as an antidote in drugs related toxicities. We determined the effects of ILE on neurotoxicity of haloperidol (HA), a highly lipophilic antipsychotic, as a model of antipsychotics poisoning. We used six groups of five male rabbits. Two groups received distilled water intravenously followed by infusions of either 18 mL/kg of normal saline or ILE 20%, after 30 minutes. The third group received 18 mL/kg of normal saline after HA (2.6 mg/kg) administration. The three other groups received ILE 20% solution (6, 12, and 18 mL/kg) following HA injection. Catalepsy scores, temperature, pupil size, and mortality rate were measured at 0, 0.5, 1, 2, 3, 4, 8, and 24 hours after HA administration began. Blood and tissue samples were taken from all animals at 24 hours or at death time for biochemical, cell count, and pathological studies. ILE reversed cataleptic scores, miotic pupils, and hypothermia of HA intoxication much faster than normal saline (P < 0.001). Biochemical complications and mortality rate of the animals were significantly higher in the HA + 18 mL/Kg ILE group. ILE reversed sings of HA neurotoxicity; however, synergistic effect of high dose of ILE and HA increased complications and mortality.

Evaluation of intravenous lipid emulsion on haloperidol-induced hypotension in rabbits

There are many reports on the effects of intravenous lipid emulsion (ILE) as an antidote in drug toxicity. Haloperidol (HAL) is a butyrophenone antipsychotic agent which is highly lipophilic. Hypotension is an important adverse effect of HAL administration and overdose. The aim of this study was to investigate the beneficial hemodynamic effects of ILE on acute HAL poisoning. We used six groups of five male rabbits. Two groups received aseptic distilled water intravenously followed by infusion of 18.6 ml/kg normal saline, as negative control group, or ILE 20% after 0.5 h. The third group received 18.6 ml/kg normal saline after HAL infusion (2.6 mg/kg). The other three groups received ILE 20% solution (6, 12, and 18.6 ml/kg) following HAL (2.6 mg/kg) administration. We measured blood pressure at 0, 0.5, 1, 2, 3, 4, 8, and 24 h after starting HAL administration, from left forelimb using a noninvasive method that was carried out automatically with a neonatal intensive care unit bedside monitor. ILE 20% at the dose of 18 ml/kg could return the reduced mean arterial pressure and diastolic blood pressure sooner than the other doses and normal saline. In conclusion, ILE could reverse HAL-induced hypotension same as the other lipophilic drugs. However, the clinical use of ILE for this purpose needs more evaluation to determine its exact indication and safety.

Trends in quetiapine use and non-fatal quetiapine-related ambulance attendances

INTRODUCTION AND AIMS

Concern about the non-medical use of quetiapine and related acute harms is growing. Case series cite quetiapine as a potential drug of misuse, while recent research questions its relative safety in comparison with other atypical antipsychotic preparations. This paper explores population-level patterns of quetiapine-related ambulance attendances over time, identifying associated risk factors and potential subpopulations at-risk of acute harms.

DESIGN AND METHODS

A retrospective analysis of quetiapine-, olanzapine- and risperidone-related ambulance attendances in metropolitan Melbourne and prescription data in Victoria, Australia. Trends in ambulance attendance and prescription rates, attendance characteristics, and associated risk factors were explored from 2001 to 2010.

RESULTS

Quetiapine was consistently associated with substantially higher rates of ambulance attendances relative to prescription availability than olanzapine or risperidone. Quetiapine prescribing rates increased at a significantly greater magnitude than olanzapine or risperidone, leading to substantial increases in quetiapine attendances by population. Quetiapine-related attendances were associated with concurrent heroin and opioid replacement therapy toxicity, history of heroin and alcohol misuse, mood disorders, low Glasgow Coma Scale and women.

DISCUSSION AND CONCLUSIONS

Trends in quetiapine-related ambulance attendances indicate rising community-level harms and greater harm relative to other atypical antipsychotics, while prescription patterns suggest increasing quetiapine availability. The association of quetiapine-related attendances with concurrent heroin and opioid replacement therapy toxicity as well as previous heroin and alcohol misuse suggest illicit and poly-drug users are a subpopulation at greater risk of quetiapine-related harms, consistent with emerging evidence of the use, misuse and diversion of quetiapine.

Fatal toxicity of drugs used in psychiatry

Certified deaths from fatal poisoning (accidents, suicides and open verdicts) in England and Wales have declined steadily (from 3952 in 1979 to 2565 in 2004). There was also a small annual reduction in suicides in males and in females over this period. In 2004, self-poisoning accounted for 25% of suicides and open verdicts in males (n = 862) and 45% in females (n = 540). Poisoning death rates per million prescriptions were about 10 times higher for tricyclic antidepressants (TCAs) than for selective serotonin reuptake inhibitors (SSRIs), England and Wales, 1993-2004. However, despite the increased prescription of SSRIs and related compounds in recent years, there has been only a slight decrease (some 10%) in the annual number of antidepressant-related poisoning deaths, in line with the reduction in suicides (all methods) over this period. Citalopram appears to have higher overdose toxicity than other SSRIs. Of newer non-SSRI antidepressants, the overdose toxicity of venlafaxine, although lower than that of TCAs, appears to be higher than that of SSRIs, with seizures, serotonin syndrome, rhabdomyolysis, renal failure and hepatic failure having been reported. Poisoning deaths involving antipsychotics either alone, or with other drugs and/or alcohol are many fewer than those involving antidepressants (713 and 5602 deaths, respectively, England and Wales, 1993-2004). Following the restriction on thioridazine usage (2000), thioridazine-associated fatal poisoning fell to zero by 2002, but this was balanced by an increase in deaths associated with atypical antipsychotics, most notably clozapine, olanzapine and quetiapine. Antipsychotic-related poisoning deaths were higher in 2004 than at any time since 1993.

IMPACT OF LEGISLATIVE CHANGES ON PATTERNS OF ANTIPSYCHOTIC PRESCRIBING AND SELF-POISONING IN SCOTLAND: 2000-06

Recently, national guidelines have advocated greater use of atypical rather than typical antipsychotics in the treatment of schizophrenia. In addition, there have been safety concerns regarding the potential cardiotoxicity of certain antipsychotics taken in overdose. This has led regulatory authorities in the United Kingdom to restrict the use of thioridazine. The overall impact of these legislative changes on patterns of antipsychotic prescribing has received comparatively little attention. Therefore, we sought to examine the effects on community prescribing practices, and to determine whether this was accompanied by changes in patterns of antipsychotic poisoning. Between 2000-03, there was a rapid decline in the use of typical antipsychotics, whereas the use of atypical antipsychotics increased. The prevalence of atypical and typical antipsychotic prescribing has been approximately equal between 2003-06. During the same study period, hospital admissions due to typical antipsychotic poisoning also declined, however, the effects lagged behind changes in prescribing practice by 2-3 years. These data indicate that legislative changes that restrict the use of thioridazine and other typical antipsychotics are associated with a measurable reduction in the number of hospital admissions due to overdose with these agents.