Changes in Fatalities Due to Overdose of Anxiolytic and Sedative Drugs in the UK (1983???1999)

Alprazolam-related deaths in Scotland, 2004-2020

BACKGROUND

The benzodiazepine drug alprazolam, a fast-acting tranquiliser, cannot be prescribed on the National Health Service in the United Kingdom. Illicit alprazolam supply and consumption have increased. Concern about increasing numbers of alprazolam-related fatalities started circulating in 2018. However, statistics on this issue are very limited. This study examined patterns in such mortality in Scotland.

METHODS

Statistics on deaths where alprazolam was mentioned in the 'cause of death' were obtained from official mortality registers. Anonymised Scottish case-level data were obtained. Data were examined in respect of the characteristics of decedents and deaths using descriptive statistics.

RESULTS

Scotland registered 370 deaths in 2004-2020; 366 of these occurred in 2015-2020: most involved males (77.1%); mean age 39.0 (SD 12.6) years. The principal underlying cause of death was accidental poisoning: opiates/opioids (77.9%); sedatives/hypnotics (15.0%). Two deaths involved alprazolam alone. Main drug groups implicated: opiates/opioids (94.8%), 'other benzodiazepines' (67.2%), gabapentinoids (42.9%), stimulants (30.1%), antidepressants (15.0%). Two-thirds (64.2%) involved combinations of central nervous system (CNS) depressants.

DISCUSSION

Alprazolam-related deaths are likely due to an increasing illicit supply. The fall in deaths in 2019-2020 is partially due to increased use of designer benzodiazepines. Treatment for alprazolam dependence is growing. Clinicians need to be aware of continuing recreational alprazolam use. When such consumption occurs with CNS depressants, overdose and death risks increase.

CONCLUSIONS

More awareness of alprazolam contributing to deaths, especially in conjunction with other CNS depressants, is needed by consumers and clinicians. Improved monitoring of illicit supplies could identify emerging issues of medicines' abuse.

Alprazolam and lorazepam overdose and the absence of brainstem reflexes

Benzodiazepines (BZDs) rarely cause respiratory depression and death. On the other hand, high-dose BZDs may lead to profound sedation and diminished brainstem functions that mimic other structural brain lesions as described in our case: a 70-year-old unresponsive woman. She was hypothermic and had rapid shallow breathing. Her Glasgow Coma Scale score was E1V1M4, with pinpoint pupils and absent corneal, oculocephalic and oculovestibular reflexes. Other physical exams, laboratory testing and brain imaging were unremarkable. After two doses of 0.4 mg naloxone and intravenous thrombolytics were given, there were no significant responses, and the diagnosis remained a mystery. The cause of her unconsciousness was uncovered when her husband found empty bags of 80 tablets of alprazolam and lorazepam. Her consciousness and brainstem reflexes improved dramatically after 0.25 mg of intravenous flumazenil. The blood for BZDs concentration showed alprazolam 268 ng/mL (20-40 ng/mL), lorazepam 861 ng/mL (20-250 ng/mL) and their metabolites.

From the clinic to the street: the changing role of benzodiazepines in the Scottish overdose epidemic

Drug-related deaths in Scotland increased for seven years in a row between 2014 and 2020 consolidating Scotland's place at the top of the United Kingdom and European drug-related mortality charts. One of the defining features of this recent and rapid rise has been the role of benzodiazepines which are now involved in two-thirds of all cases. Policy decisions over four decades have contributed to the supply and demand drivers of this unique element of the Scottish overdose crisis. An illicit market once populated by diverted prescription medications is now dominated by a toxic supply of NPS-type benzodiazepines or so-called 'street benzos' which have increased the risk environment for people who use drugs. In response, Scotland needs to urgently expand its harm reduction infrastructure and implement safer supply, drug testing and drug consumption rooms. Such a response should be made in parallel to addressing the socioeconomic inequalities which are fuelling an epidemic of global significance.

The Risk of Overdose With Concomitant Use of Z-Drugs and Prescription Opioids: A Population-Based Cohort Study

OBJECTIVE

The Z-drugs (zolpidem, zopiclone, zaleplon) are widely used to treat insomnia in patients receiving prescription opioids, and the risk of overdose resulting from this coprescription has not been explored. The authors compared the rates of overdose among patients using opioids plus Z-drugs and patients using opioids alone.

METHODS

All individuals 15 to 85 years of age receiving prescription opioids, regardless of underlying indication and without evidence of cancer, were identified in the IBM MarketScan database (2004-2017). Patients with concomitant exposure to Z-drugs were matched 1:1 to patients with exposure to prescription opioids alone based on opioid prescribed, morphine equivalents, number of days' supply, and hospitalization within the past 30 days. The primary outcome was any hospitalization or emergency department visit due to an overdose within 30 days, using an intention-to-treat approach. Fine stratification on the propensity score was used to control for confounding.

RESULTS

A total of 510,529 exposed patients and an equal number of matched reference patients were analyzed. There were 217 overdose events among the exposed patients (52.5 events per 10,000 person-years) and 57 events among the reference patients (14.4 events per 10,000 person-years), corresponding to an unadjusted hazard ratio of 3.67 (95% CI=2.75, 4.90). Using fine stratification on the propensity score (c-statistic: 0.66), the adjusted hazard ratio was 2.29 (95% CI=1.79, 2.91). Results were consistent across sensitivity analyses.

CONCLUSIONS

Among patients receiving prescription opioids, after controlling for all confounding factors, concomitant treatment with Z-drugs was associated with a substantial relative increase in the risk of overdose. The potential implications are significant given the large number of opioid-treated patients receiving Z-drugs.

Recent trends in barbiturate detection in medicolegal deaths

A study was undertaken of 51 cases where barbiturates were detected in post-mortem blood samples from 2000 to 2019 at Forensic Science South Australia, Adelaide, Australia. The cause of death was drug toxicity in only 27 (53%) (M:F = 19:8; age range 19-74yrs, mean 46yrs). In 17 cases, barbiturate toxicity was the primary cause of death, 14 due to pentobarbitone and 3 to phenobarbitone. All were suicides. Barbiturates were obtained by online purchase from overseas sources in 9 cases (33%), and through veterinary practice in 2 cases (7%). Drug toxicity deaths where barbiturates were detected rose from 1 in 2000-2004 to 11 in 2015-2019, and those where deaths were primarily due to barbiturate toxicity rose from 1 in 2000-2004 to 9 in 2015-2019. However, the mere detection of barbiturates in post mortem samples did not equate with illicit use, as 23 of the deaths (45%) were due to natural causes in individuals prescribed barbiturates for epilepsy. The usefulness of examining subset populations separate from accrued national data is also demonstrated in the significantly younger age of decedents in South Australia dying from deliberately administered barbiturates (46 yrs) compared to the national average of 57.9 yrs. The reasons for this difference will require further investigation as this may impact upon local suicide prevention strategies.

'Z-trip'? A Comprehensive Overview and a Case-series of Zolpidem Misuse

Although believed safer compared to short-acting benzodiazepines (BZD), in the past few years a growing concern has developed relating to the abuse of Z-drugs, and specifically of zolpidem. Here we aim to review the evidence for the misuse of zolpidem and describe several related cases collected in Italy. A comprehensive overview is here carried by using several databases, and by combining the search strategy of free text terms and exploding a range of MESH headings relating to the topics of Zolpidem and Abuse and/or Misuse as follows: ((Zolpidem[Title/Abstract]) AND (Abuse[Title/Abstract]) OR (Misuse[Title/Abstract])), without time and/or language restrictions. Furthermore, a case series of 8 cases of zolpidem misuse and/or abuse, collected in different Italian psychiatric settings (psychiatric public hospital, psychiatric private rehabilitation clinic, and private practice), have been here described. According to our findings, zolpidem should be prescribed with the same caution as BZDs, especially in patients with a history of drug abuse or in the elderly. Behavioural modifications, including bizarre behaviours, psychomotor agitation, sleep-related complex behaviours have been reported. Monitoring of zolpidem use in selected populations is warranted. Psychiatrists and physicians should be aware of the misuse potential of zolpidem and adopt measures restricting its use.

Protective effect of flumazenil infusion in severe acute benzodiazepine toxicity: a pilot randomized trial

OBJECTIVE

We aimed to investigate the efficacy of flumazenil infusion in the maintenance of arousal and prevention of development of complications in severe benzodiazepine poisoning.

MATERIALS AND METHOD

Sixty severely poisoned patients (intubated due to loss of consciousness) intoxicated by sole benzodiazepines referred to Loghman Hakim hospital between May 2018 and August 2019 were considered to be included in the current study. All were evaluated for possible contraindications of flumazenil administration. If there were no contraindications, we continued supportive care in one group and supportive care plus flumazenil infusion in the second group. Following response to the stat dose of flumazenil, complications, hospital stay, and outcome were compared between these two groups.

RESULTS

A total of 60 benzodiazepine-poisoned patients aged between 16 and 84 years old (37 males and 23 females) were enrolled. There was no statistically significant difference between these two groups regarding the period of hospital stay. Need for intubation significantly decreased in the infusion group. None of the patients experienced seizure or dysrhythmia. One patient died in the control group which received only a stat dose of flumazenil.

CONCLUSIONS

Administration of flumazenil is safe in benzodiazepine-poisoned patients with appropriate indications. Flumazenil infusion can significantly decrease the need for intubation and subsequent ICU admission. Even though flumazenil is an expensive antidote, its administration may decrease the need for ICU beds in the setting of acute poisoning.

An Insight into Z-Drug Abuse and Dependence: An Examination of Reports to the European Medicines Agency Database of Suspected Adverse Drug Reactions

BACKGROUND

Although originally marketed as safe alternatives to the habit-forming benzodiazepines, growing numbers of zaleplon, zolpidem, and zopiclone ("Z-drugs") clinical concerns relating to their potential of abuse, dependence, and withdrawal have been reported over time. We aimed here at assessing these issues analyzing datasets of adverse drug reactions provided by the European Medicines Agency through the EudraVigilance system.

METHODS

Analyzing the adverse drug reactions databases of each Z-drug, descriptive analyses have been performed on cases and proportional reporting ratios (PRRs) computed.

RESULTS

An overall number of 33 240 (e.g., 23 420 zolpidem; 9283 zopiclone; and 537 zaleplon) misuse-, abuse-, dependence-, and withdrawal-related adverse drug reactions, corresponding to some 6246 unique patients given Z-drugs, were here identified. Cases were studied and described, including demographic characteristics and clinical data such as concomitant drugs, doses, routes of administration, and outcomes of the reactions (being fatalities recorded). Considering PRR values and in comparison with zopiclone, zolpidem was more frequently involved in both misuse/abuse and withdrawal issues. Zolpidem and zopiclone presented with the same dependence risk, but zopiclone was most involved in overdose adverse drug reactions. Compared with zaleplon, zopiclone presented higher dependence and overdose-related issues but slightly lower misuse/abuse and withdrawal PRR values.

CONCLUSION

Current data may only represent a gross underestimate of the real prevalence of Z-drug misuse. Caution should be exercised when prescribing those molecules, especially for patients with psychiatric illnesses and/or history of drug abuse. We recommend the need to invest in proactive pharmacovigilance activities to better and promptly detect, understand, and prevent any possible misuse potential of prescribed medications.

Benzodiazepines and Z-Drugs: An Updated Review of Major Adverse Outcomes Reported on in Epidemiologic Research

Various adverse events resulting from, or associated with, benzodiazepine and/or Z-drug use have been extensively reported on and discussed in great detail within the biomedical literature. It is widely accepted that motor vehicle accidents and falls leading to fractures in older adults are major adverse events that have been shown to occur more frequently in users of sedative-hypnotic medication, especially of the benzodiazepine and related Z-drug variety. However, the last few years have seen increasing reports in the literature raising the issue of benzodiazepine and Z-drug exposure in the development of other serious medical issues including dementia, infections, respiratory disease exacerbation, pancreatitis, and cancer. This article provides an overview and interpretation on the current state of evidence regarding each of these associations and proposes what gaps in the evidence for drug-exposure–harm associations need to be addressed in the future for the purpose of evaluating causality of harm as it relates to these drugs.

Relative toxicity of benzodiazepines and hypnotics commonly used for self-poisoning: An epidemiological study of fatal toxicity and case fatality

The relative toxicity of anxiolytic and hypnotic drugs commonly used for self-poisoning was assessed using data on suicides, prescriptions and non-fatal self-poisonings in England, 2005-2012. Data on suicide by self-poisoning were obtained from the Office for National Statistics, information on intentional non-fatal self-poisoning was derived from the Multicentre Study of Self-harm in England and data on prescriptions in general practice from the Clinical Practice Research Datalink. We used two indices of relative toxicity: fatal toxicity (the number of fatal self-poisonings relative to the number of individuals prescribed each drug) and case fatality (the number of fatal relative to non-fatal self-poisonings). Diazepam was the reference drug in all analyses. Temazepam was 10 times (95% confidence interval 5.48-18.99) and zopiclone/zolpidem nine times (95% confidence interval 5.01-16.65) more toxic in overdose than diazepam (fatal-toxicity index). Temazepam and zopiclone/zolpidem were 13 (95% confidence interval 6.97-24.41) and 12 (95% confidence interval 6.62-22.17) times more toxic than diazepam, respectively (case-fatality index). Differences in alcohol involvement between the drugs were unlikely to account for the findings. Overdoses of temazepam and zopiclone/zolpidem are considerably more likely to result in death than overdoses of diazepam. Practitioners need to exercise caution when prescribing these drugs, especially for individuals who may be at risk of self-harm, and also consider non-pharmacological options.

Substance misuse-related poisoning deaths, England and Wales, 1993–2016

Context

In recent years there has been an increase in the availability of ‘novel psychoactive substances (NPS)’ or ‘legal highs’. In turn, there is concern as to the risks these compounds pose as compared to those posed by traditionally misused substances such as illicit diamorphine (heroin), methadone, cocaine, and amfetamines.

Methods

We reviewed deaths where opiates/opioids, stimulants, hypnosedatives, hallucinogens, or volatile substances were mentioned on the death certificate in England and Wales, 1993–2016 as recorded on the Office for National Statistics drug poisoning deaths database. Deaths were analysed by year of registration of death, age, sex, intent, drug(s) involved, and the presence of alcohol (ethanol).

Results

There were 68,347 drug-related deaths in England and Wales (includes both licit and illicit substances), of which 15,457 were either coded as, or had mention of, drug dependent/non-dependent substance abuse on the death certificate. Opioids, particularly diamorphine/morphine and methadone, featured in most deaths. Diamorphine/morphine-related deaths (17,402) increased from 155 in 1993 to 981 in 2001, and then remained relatively stable until 2010 (791). Thereafter, annual numbers of deaths fell to 579 in 2012, but have since increased to 1,209 (2016). Deaths in the age group 20–29 years declined from 46% (1993), to 13% (2016), whereas in those aged 40–49 years the percentage of deaths increased from 13% (1993) to 33% (2016). Methadone was mentioned in 7,894 deaths (1993–2016). Annual numbers of such deaths increased from 206 to 437, 1993–7, then declined, but have since increased, reaching 413 in 2016. As to age, a similar pattern as to diamorphine/morphine-related deaths is apparent. Annual numbers of deaths involving cocaine (1993–2016: 3,342), reached 235 in 2008, declined, but have since increased (2011: 112, 2016: 371). Annual numbers of deaths involving methylenedioxyamfetamine/ methylenedioxyethamfetamine/ methylenedioxymetamfetamine (‘ecstasy’) (1993–2016: 853), have also increased steadily in recent years (2010; 8, 2016: 65). There were relatively few mentions of ‘novel stimulants’ (1993–2016: 386) on death certificates and such deaths have declined in recent years (2015: 88, 2016: 57). Mephedrone was most frequently mentioned (122), as was para-methoxyamfetamine/ para-methoxymetamfetamine (88). Conversely, although synthetic cannabinoids were mentioned infrequently (1993–2016: 37), such deaths have increased recently (2015: 8, 2016: 26).

Conclusions

Illicit diamorphine (heroin) and methadone continue to be the principal drugs of abuse involved in fatal poisonings in England and Wales. The increase in such deaths in recent years has been largely due to an increase in deaths amongst older users, although the role of potent synthetic opioids such as carfentanil is a cause for concern. Overall, stimulants and related compounds have been implicated in an increasing number of deaths annually. The impact of the plethora of NPS that have appeared in recent years on fatal poisonings may have been mitigated by legislation.

Risk markers for fatal and non-fatal prescription drug overdose: a meta-analysis

BACKGROUND

Drug overdose is a public health crisis in the United States, due in part to the unintended consequences of increases in prescribing of opioid analgesics. Many clinicians evaluate risk markers for opioid-related harms when prescribing opioids for chronic pain; however, more data on predictive risk markers are needed. Risk markers are attributes (modifiable and non-modifiable) that are associated with increased probability of an outcome. This review aims to identify risk markers associated with fatal and non-fatal prescription drug overdose by synthesizing findings in the existing peer-reviewed and grey literature. Eligible cohort, case-control, cross-sectional, and case-cohort studies were reviewed and data were extracted for qualitative and quantitative synthesis.

FINDINGS

Summary odds ratios (SOR) were estimated from 29 studies for six risk markers: sex, age, race, psychiatric disorders, substance use disorder (SUD), and urban/rural residence. Heterogeneity was assessed and effect estimates were stratified by study characteristics. Of the six risk markers identified, SUD had the strongest association with drug overdose death (SOR = 5.24, 95% confidence interval (CI) = 3.53 - 7.76), followed by psychiatric disorders (SOR = 3.94, 95% CI = 3.09 - 5.01), white race (SOR = 2.28, 95% CI = 1.93 - 2.70), the 35-44 year age group relative to the 25-34 year reference group (SOR = 1.52, 95% CI = 1.31 - 1.76), and male sex (SOR = 1.33, 95% CI = 1.17 - 1.51).

CONCLUSIONS

This review highlights fatal and non-fatal prescription drug risk markers most frequently assessed in peer-reviewed and grey literature. There is a need to better understand modifiable risk markers and underlying reasons for drug misuse in order to inform interventions that may prevent future drug overdoses.

The antipsychotic story: changes in prescriptions and overdose without better safety

AIMS

Morbidity and mortality from drug overdose has decreased over three decades. This is credited to safer drugs and therefore better outcomes in overdose. We aimed to investigate changing prescriptions of antipsychotic medications and associated changes in antipsychotic overdoses over a 26-year period.

METHODS

All antipsychotic poisoning presentations to a tertiary referral toxicology unit between 1987 and 2012 were reviewed. Data were collected prospectively on demographics, ingestion information, clinical effects, complications and treatment. Rates of antipsychotic drug use in Australia were obtained from Australian government publications for 1990-2011 and linked to overdose admissions by postcode.

RESULTS

There were 3180 antipsychotic overdoses: 1235 first generation antipsychotics, 1695 'atypical' second generation antipsychotics and 250 lithium overdoses. Over 26 years, antipsychotic overdoses increased 1.8-fold, with first generation antipsychotics decreasing to one-fifth of their peak (≈80/year to 16) and second generation antipsychotics increasing to double this (≈160/year), olanzapine and quetiapine accounting for 78%. All antipsychotic overdoses had a median length of stay of 18.6 h, 15.7% admitted to intensive care unit, 10.4% ventilated and 0.13% died in hospital, which was the same for first generation compared to second generation antipsychotics. There was a 2.3-fold increase in antipsychotic prescriptions over the same period; first generation antipsychotics declined whereas there was a dramatic rise in second generation antipsychotics, mainly olanzapine, quetiapine and risperidone (79%).

CONCLUSION

Over 26 years there was an increase in antipsychotic prescribing associated with an increase in antipsychotic overdoses. Although the type of antipsychotics changed, the morbidity and mortality remained the same, so that antipsychotics are an increasing proportion of overdose admissions.

Conscious Intravenous Sedation in Dentistry: A Review of Current Therapy

Several sedation options are used to minimize pain, anxiety, and discomfort during oral surgery procedures. Minimizing or eliminating pain and anxiety for dental care is the primary goal for conscious sedation. Intravenous conscious sedation is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands. No interventions are required to maintain a patent airway, and spontaneous ventilation is adequate as well as cardiovascular function. Patients must retain their protective airway reflexes, and respond to and understand verbal communication. The drugs and techniques used must therefore carry a broad margin of safety.

Characteristics and trends of emergency patients with drug overdose in Osaka

Aim

Drug overdose is an important issue in emergency medicine. However, studies covering overdose patients transported by ambulance have not been sufficiently carried out. We attempted to clarify problems of suspected drug overdose patients transported by ambulance.

Methods

This is a prospective population-based cohort study. Data were collected by emergency medical service crews in Osaka City, Japan, between January 1998 and December 2010.

Results

Drug overdose cases increased annually from 1,136 in 1998 to 1,822 in 2010 (P < 0.0001 for trend). In these cases, the dominant age range was between 16 and 40 years and the age distribution did not change over time. The age of non-overdose cases increased (P < 0.0001 for trend), with patients aged ≥66 years becoming most common in recent years, reflecting the aging of society. Males comprised most non-overdose patients, but the percentage of females increased annually (P < 0.0001 in trend). Females comprised approximately 70% in overdose cases annually throughout the study period. The duration from the emergency call to the arrival at the hospital for overdose patients has increased markedly in recent years. It also takes more time to obtain acceptance from hospitals to care for patients of suspected overdose.

Conclusion

The characteristics of drug overdose patients are clearly different from those of non-overdose patients. Recent trends of drug overdose patients indicate the accelerated burden on emergency medical services system.

The clinical and forensic toxicology of Z-drugs

The Z-drugs zolpidem, zopiclone, and zaleplon were hailed as the innovative hypnotics of the new millennium, an improvement to traditional benzodiazepines in the management of insomnia. Increasing reports of adverse events including bizarre behavior and falls in the elderly have prompted calls for caution and regulation. Z-drugs have significant hypnotic effects by reducing sleep latency and improving sleep quality, though duration of sleep may not be significantly increased. Z-drugs exert their effects through increased γ-aminobutyric acid (GABA) transmission at the same GABA-type A receptor as benzodiazepines. Their pharmacokinetics approach those of the ideal hypnotic with rapid onset within 30 min and short half-life (1-7 h). Zopiclone with the longest duration of action has the greatest residual effect, similar to short-acting benzodiazepines. Neuropsychiatric adverse events have been reported with zolpidem including hallucinations, amnesia, and parasomnia. Poisoning with Z-drugs involves predominantly sedation and coma with supportive management being adequate in the majority. Flumazenil has been reported to reverse sedation from all three Z-drugs. Deaths from Z-drugs are rare and more likely to occur with polydrug overdose. Z-drugs can be detected in blood, urine, oral fluid, and postmortem specimens, predominantly with liquid chromatography-mass spectrometry techniques. Zolpidem and zaleplon exhibit significant postmortem redistribution. Zaleplon with its ultra-short half-life has been detected in few clinical or forensic cases possibly due to assay unavailability, low frequency of use, and short window of detection. Though Z-drugs have improved pharmacokinetic profiles, their adverse effects, neuropsychiatric sequelae, and incidence of poisoning and death may prove to be similar to older hypnotics.

[Delirium in elderly patients]

BACKGROUND

Delirium, «acute confusional state», is a frequent and serious complication of acute illness, particularly in the elderly. The strain on the patient, the next of kin and the health service is considerable. The purpose of the article is to provide healthcare personnel who deal with delirium with updated information about the condition.

METHOD

The article is based on a literature search in PubMed combined with articles from the author's own archives and own clinical experience.

RESULTS

Delirium is a serious acute medical condition that is often overlooked in the elderly. The prevalence is estimated to be between 11% and 42% for elderly patients on medical wards and close to 50% in patients with hip fractures. The prevalence is probably also high in nursing homes, but this is less well surveyed. Advanced age and dementia are the most important risk factors. Traumas, infections, stroke and metabolic disturbances are the most common triggering factors. The pathophysiology is poorly surveyed and the possibilities for drug treatment are few and are little studied. Delirium is associated with increased risk of dementia, loss of function and mortality. Short-term use of low-dosage antipsychotics is the first-line choice, but is contraindicated for patients with Parkinsonian symptoms.

INTERPRETATION

Detection and treatment of triggering causes must have high priority in case of delirium. Non-drug interventions are most important to prevent and treat the condition.

Enhanced elimination in acute barbiturate poisoning - a systematic review

CONTEXT

Despite a worldwide decline in barbiturate use, cases of acute poisoning with severe toxicity are still noted, particularly in developing countries. Severe poisonings often require prolonged admission to an intensive care unit, so enhanced elimination might be useful to hasten recovery. Information regarding the efficacy of these techniques for individual barbiturates is not available in standard textbooks.

OBJECTIVE

To determine the evidence supporting the effect of enhanced elimination and its role in the management of acute barbiturate poisoning.

METHODS

A systematic review was conducted using broad search criteria in three databases. All potentially relevant articles were obtained, and reference lists were manually reviewed. Ninety-four publications fulfilling inclusion criteria were located. Studies were classified as controlled or uncontrolled, and clinical and pharmacokinetic end points were manually extracted. If not directly stated, standard pharmacokinetic methods were used to calculate the clearance and efficiency of enhanced elimination techniques for each barbiturate and tabulated for direct comparison. PROSPECTIVE CONTROLLED CLINICAL TRIALS: Two of the 94 publications were prospective controlled studies (only one stated that allocation was via blinded randomisation), and both assessed the effect of multiple-dose activated charcoal for acute phenobarbital poisoning. These studies demonstrated enhanced elimination with a decrease in elimination of half-life from approximately 80 to 40?h, but only one study reported clinical benefits. UNCONTROLLED SERIES AND SINGLE CASE REPORTS: Sufficient data to determine the clearance due to enhanced elimination were available in only 52 of these papers. Barbiturate clearances by enhanced elimination varied markedly among studies. While extracorporeal modalities appeared to increase the direct clearance of many barbiturates, there was insufficient information to confirm a clinical benefit.

CONCLUSIONS

There is limited evidence to support the use of enhanced elimination in the treatment of poisoning with most barbiturates. There is no role for urine alkalinisation, while multiple-dose activated charcoal may be useful for most phenobarbital and possibly primidone poisonings. Extracorporeal techniques appear to enhance elimination, but the clinical benefits, relative to the potential complications and cost, are poorly defined. Extracorporeal techniques such as haemodialysis and haemoperfusion can be considered for patients with life-threatening barbiturate toxicity such as refractory hypotension.

Long-term misuse of zopiclone in an alcohol dependent woman with a history of anorexia nervosa: a case report

INTRODUCTION

The Z-drugs, zaleplon, zopiclone and zolpidem, are short-acting hypnotics which act at the same receptor as the benzodiazepines, but seemingly without the potential for misuse and the development of dependence of the older benzodiazepines. However, with increased prescribing of Z-drugs, reports of misuse and possible dependence began to appear in the literature, particularly in people with a history of substance misuse and comorbid psychiatric illness. Here we report the case of a woman with a history of chronic zopiclone use and anorexia nervosa, admitted for alcohol detoxification.

CASE PRESENTATION

A 31-year old Caucasian British woman with a history of long-term zopiclone use and anorexia nervosa was admitted as an inpatient for a ten-day alcohol detoxification. Her weekly (four days out of seven) intake of alcohol was 180 units and her daily intake of zopiclone, 30 mg. Apart from a short period five years ago, she had been taking zopiclone for 13 years at daily doses of up to 90 mg. She admitted to using 'on top' of her prescribed medication, purchasing extra tablets from friends or receiving them gratis from her partner. After detoxification from alcohol and zopiclone, she was prescribed diazepam which she found ineffectual and voiced her intention of returning to zopiclone on leaving the hospital.

CONCLUSION

Zopiclone is generally regarded as safer than benzodiazepines, however, this particular individual, who was using high doses of zopiclone over many years, may provide further evidence of a risk of dependency when this drug is prescribed for substance users with a comorbid psychiatric illness.

A systematic review of research examining benzodiazepine-related mortality

PURPOSE

This paper will review literature examining the association of benzodiazepine use and mortality.

METHODS

An extensive literature review was undertaken to locate all English-language published articles that examine mortality risk associated with use of benzodiazepines from 1990 onwards.

RESULTS

Six cohort studies meeting the criteria above were identified. The results were mixed. Three of the studies assessed elderly populations and did not find an increased risk of death associated with benzodiazepine use, whereas another study of the general population did find an increased risk, particularly for older age groups. A study of a middle aged population found that regular benzodiazepine use was associated with an increased mortality risk, and a study of 'drug misusers' found a significant relationship between regular use of non-prescribed benzodiazepines and fatal overdose. Three retrospective population-based registry studies were also identified. The first unveiled a high relative risk (RR) of death due to benzodiazepine poisoning versus other outcomes in patients 60 or older when compared to those under 60. A positive but non-significant association between benzodiazepine use and driver-responsible fatalities in on-road motor vehicle accidents was reported. Drug poisoning deaths in England showed benzodiazepines caused 3.8% of all deaths caused by poisoning from a single drug.

CONCLUSION

On the basis of existing research there is limited data examining independent effects of illicit benzodiazepine use upon mortality. Future research is needed to carefully examine risks of use in accordance with doctors' prescriptions and extra-medical use.

beta-Adrenergic blockers: a 50-year historical perspective

The development and subsequent clinical application of the beta-adrenergic receptor blocking drugs over the past 50 years represent one of the major advances in human pharmacotherapy. No other class of synthetic drugs has demonstrated such widespread therapeutic utility for the treatment of so many cardiovascular and noncardiovascular diseases. In addition, these drugs have proven to be molecular probes that have contributed to our understanding of disease, and on the molecular level, both the structure and the function of the 7 transmembrane G protein receptors, which mediate the actions of many different hormones, neurotransmitters, and drugs. The evolution of beta-blocker drug development has led to refinements in their pharmacodynamic actions that include agents with relative beta1-selectivity, partial agonist activity, concomitant alpha-adrenergic blockers activity, and direct vasodilator activity. In addition, long-acting and ultra-short-acting formulations of beta-blockers have also demonstrated a remarkable record of clinical safety in patients of all ages. Indeed, the beta-adrenergic blockers have provided us with a great clinical legacy for now and in years to come.

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.

Unintentional prescription drug overdose deaths in New Mexico, 1994-2003

BACKGROUND

New Mexico has the highest rate of drug-induced mortality in the United States. The contribution of prescription drugs to the total overdose death rate has not been adequately described.

METHODS

A total of 1,906 unintentional drug overdose deaths occurring in 1994 to 2003 in New Mexico were analyzed. Unintentional drug overdose death was defined as death caused by prescription, illicit, or a combination of drugs, as determined by a pathologist. Deaths were investigated annually by the medical examiner and data were analyzed in 2004-2005. Rates and trends of total and prescription drug overdose death were calculated, decedent characteristics were analyzed, and common drug combinations causing death were described.

RESULTS

The rate of unintentional prescription drug overdose death increased by 179% (1.9 to 5.3/100,000) from 1994 to 2003. A high percentage of prescription drug overdose decedents were white non-Hispanic (63.2%) and female (43.9%). These decedents were older and less frequently had alcohol listed as an additional cause of death than decedents of other drug overdose categories. Of all deaths caused by prescription drug(s) (n =765), 590 (77.1%) were caused by opioid painkillers, 263 (34.4%) by tranquilizers, and 196 (25.6%) by antidepressants.

CONCLUSIONS

The rate of prescription drug overdose death in New Mexico increased significantly over the 10-year study period. Comprehensive surveillance of drug overdose deaths is recommended to describe their occurrence in the context of both medical and diverted use of prescription drugs. Understanding decedent profiles and the potential risk factors for prescription drug overdose death is crucial for effective drug overdose prevention education among healthcare providers.

Cerebral and plasma kinetics of a high dose of midazolam and correlations with its respiratory effects in rats

Benzodiazepine poisoning causes coma and respiratory depression. Our objective was to determine whether, and to what extent, arterial blood gas disturbances correlated with blood or cerebral kinetics of midazolam. A 160 mgkg(-1) single dose of midazolam was infused intravenously over 20 min in catheterized male Sprague-Dawley rats. Midazolam kinetics was simultaneously determined in plasma and brain using striatal microdialysis. Midazolam concentrations were measured using a high-performance liquid chromatographic assay with ultraviolet detection. Midazolam (160 mgkg(-1)) reproducibly induced deep coma with respiratory acidosis. Plasma midazolam kinetics was well described by a bi-exponential model, with an elimination half-life of 6.4+/-1.8 h. The striatal dialysate concentration peaked at 50.0+/-8.9 min after the end of infusion, with a significant delay to peak concentration compared to plasma. Respiratory depression, assessed by the elevation in PaCO2, was more closely correlated with midazolam striatal dialysate rather than plasma kinetics. These results suggest a central mechanism for midazolam respiratory effects at toxic doses in rats. In conclusion, our study showed a delayed onset in peak PaCO2 and pH effects after the slow infusion of a toxic dose of midazolam in rats. The effects on arterial blood gases were better correlated with midazolam striatal concentrations than with plasma concentrations. This study may contribute to better understanding of benzodiazepine-induced respiratory depression in poisonings.

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

Prescription of atypical antipsychotics has increased in recent years. There have also been changes in the guidance on using older drugs, particularly the restriction in the use of thioridazine. We analysed deaths due to poisoning involving antipsychotics in England and Wales, 1993-2002, by age, sex, intent, and agents involved. We also studied antipsychotic prescribing in the community and poisoning deaths in England. Deaths attributed to adverse reactions in the course of normal treatment were not studied because these deaths are not classified as 'poisonings'. The number of deaths involving antipsychotics increased from around 55 per year 1993-1998 to 74 in 2000, and then fell to 53 in 2002. Around 25% of deaths had a verdict of accidental death and in about 60% of deaths a verdict of suicide or an open verdict was recorded. There were no deaths involving thioridazine in 2002, following its removal from use in 2001. However, the number of deaths associated with atypicals, most notably olanzapine and clozapine, has increased. Age-specific death rates were highest in those aged 30-39 and 40-49 years, and were very low in those aged under 20 and 70 or over. Death rates in males were greater than in females. For many drugs the proportion mentions either alone or with ethanol, was 25-45%, but for clozapine and olanzapine such mentions totalled 65-69%. Deaths per million prescriptions (clozapine excluded) were highest for quetiapine (31.3 per million), chlorpromazine (29.4 per million) and thioridazine (15.5 per million).