Deaths by unintentional illicit drug overdose in Italy, 1984-2000

A Scientometric Visualization Analysis for Molecular Mechanisms of Substance Abuse and Its Neurotoxicity From 1997 to 2021

Substance abuse has become a global problem due to drug-induced addiction and neurotoxicity, which causes a huge physical, social, and financial burden. Various kinds of drugs can hijack the users’/abusers’ behavior and associated neurocircuitry. To summarize recent scientific advances on drug abuse, we reviewed relevant publications to analyze research progress and such trends through bibliometric ways. Based on retrieval strategies, a total of 681 scientific records published from 1997 to 2021 were screened and included in the Web of Science (WoS) database. Further scientometric analysis revealed that annual publication output increased across this period, with the United States of America (USA) contributing a significant number of reasons. Research has focused on neurotransmitter, oxidative stress, mitochondrial system injury, and other neurotoxic mechanisms. Neuroimmune, neurotoxic targets, and new psychoactive substances have been hot topics in recent years, which deserve continued research in the future. Specific research on molecular mechanisms has progressed across this period, with an emphasis on the root cause of toxicity and molecular targets for therapy. Moreover, collaborations of international multi-disciplinary research teams have been efficient and need to be encouraged for addiction research and the development of appropriate therapeutic processes.

Similarities and changes between 15- and 24-year survival and retention rates of patients in a large medical-affiliated methadone maintenance treatment (MMT) center

BACKGROUND

Environmental and social trends and patients' characteristics may affect predictors for methadone maintenance treatment (MMT) outcome.

METHODS

We have expanded our previous study of predictors for MMT outcome (from 619 to 890 patients) and the study period (from 15 to 24 years). Survival and retention in MMT since admission to the MMT clinic (6/1993-6/2016) and until death or study closure (6/2017) were compiled and analyzed.

RESULTS

Of 890 patients ever admitted (10,146.9 person-years (py)), 237 passed away (116 while in MMT). The mortality rate did not differ between those who stayed or left (2.6 vs. 2.1 per 100 py, p = 0.1), but it was lower among those who stayed ≥1 year during any admission (2.1 vs. 3.3 per 100 py, respectively, p = 0.004). Age <40 years, no hepatitis C or B, no HIV, and no benzodiazepine abuse after one year predicted longer survival (multivariate analyses). No opiate or benzodiazepine abuse after one year, methadone dose ≥100 mg/d, no DSM-IV-TR Axis II diagnosis only, and no direct hospital referral predicted longer retention. Cocaine abuse predicted poor retention and survival among 271 patients admitted during the extended part of the study period.

CONCLUSIONS

Predictors for retention (associated with MMT outcome) and mortality (associated with pre-treatment comorbidity) after 24 years were similar to those after 15 years. Cocaine abuse as a predictor of both poor retention and poor survival in the later period may reflect the escalating trend for cocaine abuse and should be studied if related to other unmonitored substances.

Mortality trends among heroin users treated between 1975 and 2013 in Northern Italy: Results of a longitudinal study

BACKGROUND

The aim of this study was to examine heroin mortality trends and changes in causes of death, across time and age, in a cohort of the heroin population of treated.

METHODS

5899 subjects attending twelve centers for addiction treatment (SERT) in north Italy following problems due to heroin abuse between 1975 and 2013 were recruited.

RESULTS

This study documented elevated mortality among subjects with primary heroin abuse, with an elevated death risk in all the classes of age, declining until 2009 ad increasing starting from 2010. AIDS was the first cause of death, followed by overdose and liver-related diseases. In the course of time mortality for AIDS and for drug-related deaths has declined, whereas liver mortality and all tumors mortality have risen over time, becoming the most common causes of death by the end of the follow up. As compared with the general population, the excess mortality (SMR) observed for all causes in either sex was 13.2, higher in females (SMR=21.5) as compared with males (SMR=12.1). Higher SMRs were found in 25/34 age-group patients, with a progressive decrease in subjects with age >34years.

CONCLUSIONS

In the course of time, among heroin users, mortality and the causes of death have changed; for SERT clients special attention should be paid to the prevention and treatment of liver-related diseases.

Non-fatal overdose as a risk factor for subsequent fatal overdose among people who inject drugs

OBJECTIVES

To examine the relationship between non-fatal overdose and risk of subsequent fatal overdose.

METHODS

We assessed risk factors for overdose death among two prospective cohorts of persons who inject drugs (PWID) in Vancouver, Canada. Extended Cox regression was used to examine if reports of non-fatal overdose were associated with the time to fatal overdose while adjusting for other behavioral, social and structural confounders.

RESULTS

Between May, 1996 and December, 2011, 2317 individuals were followed for a median of 60.8 months. In total, 134 fatal overdose deaths were identified for an incidence density of 8.94 (95% confidence interval [CI]: 7.55-10.59) deaths per 1000 person-years. During the study period there were 1795 reports of non-fatal overdose. In a multivariate model, recent non-fatal overdose was independently associated with the time to overdose mortality (adjusted hazard ratio [AHR]=1.95; 95% CI: 1.17-3.27). As well, there was a dose response effect of increasing cumulative reports of non-fatal overdose on subsequent fatal overdose.

CONCLUSION

Reports of recent non-fatal overdose were independently associated with subsequent overdose mortality in a dose-response relationship. These findings suggest that individuals reporting recent non-fatal overdose should be engaged with intensive overdose prevention interventions.

Community-based interventions to prevent fatal overdose from illegal drugs: a systematic review protocol

INTRODUCTION

Drug overdose is the most frequent cause of death among people who misuse illegal drugs. People who inject these drugs are 14-17 times more likely to die than their non-drug using peers. Various strategies to reduce drug-related deaths have failed to meet target reductions. Research into community-based interventions for preventing drug overdose deaths is promising. This review seeks to identify published studies describing community-based interventions and to evaluate their effectiveness at reducing drug overdose deaths.

METHODS AND ANALYSIS

We will systematically search key electronic databases using a search strategy which groups terms into four facets: (1) Overdose event, (2) Drug classification, (3) Intervention and (4) Setting. Searches will be limited where possible to international literature published in English between 1998 and 2014. Data will be extracted by two independent reviewers using a predefined table adapted from the Cochrane Collaboration handbook. The quality of included studies will be evaluated using the Cochrane Collaboration's tool for assessing risk of bias. We will conduct a meta-analysis for variables which can be compared across studies, using statistical methods to control for heterogeneity where appropriate. Where clinical or statistical heterogeneity prevents a valid numerical synthesis, we will employ a narrative synthesis to describe community-based interventions, their delivery and use and how effectively they prevent fatal overdoses.

ETHICS AND DISSEMINATION

We will publish findings from this systematic review in a peer-reviewed scientific journal and present results at national and international conferences. It will be disseminated electronically and in print.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42015017833.

Difficulties in recording mortality resulting from drug abuse

It is considered, according to statements from different sources, that data on the number of deaths in the population of a certain country or region are accurate and correct, but determining causes of death is, for different reasons, often incorrect. There is, therefore,a justified doubt that there are more inaccurately registered drug abuse-related deaths in state registries. Hence, this paper tends to show the most frequent difficulties encountered when recording mortality resulting from drug abuse.

High risk and little knowledge: overdose experiences and knowledge among young adult nonmedical prescription opioid users

BACKGROUND

Opioid-involved overdoses in the United States have dramatically increased in the last 15 years, largely due to a rise in prescription opioid (PO) use. Yet few studies have examined the overdose knowledge and experience of nonmedical PO users.

METHODS

In depth, semi-structured, audio-recorded interviews were conducted with 46 New York City young adults (ages 18-32) who reported using POs nonmedically within the past 30 days. Verbatim interview transcripts were coded for key themes in an analytic process informed by grounded theory.

RESULTS

Despite significant experience with overdose (including overdose deaths), either personally or within opioid-using networks, participants were relatively uninformed about overdose awareness, avoidance and response strategies, in particular the use of naloxone. Overdose experiences typically occurred when multiple pharmaceuticals were used (often in combination with alcohol) or after participants had transitioned to heroin injection. Participants tended to see themselves as distinct from traditional heroin users, and were often outside of the networks reached by traditional opioid safety/overdose prevention services. Consequently, they were unlikely to utilize harm reduction services, such as syringe exchange programs (SEPs), that address drug users' health and safety.

CONCLUSIONS

These findings suggest that many young adult nonmedical PO users are at high risk of both fatal and non-fatal overdose. There is a pressing need to develop innovative outreach strategies and overdose prevention programs to better reach and serve young PO users and their network contacts. Prevention efforts addressing risk for accidental overdose, including opioid safety/overdose reversal education and naloxone distribution, should be tailored for and targeted to this vulnerable group.

Making sense of differing overdose mortality: contributions to improved understanding of European patterns

The European Monitoring Centre for Drugs and Drug Addiction, EMCDDA, publishes statistics for overdose deaths giving a European mean number, and ranking nations in a national 'league table' for overdose deaths. The interpretation of differing national levels of mortality is more problematic and more complex than is usually recognised. Different systems are used to compile mortality data and this causes problems for cross-national comparisons. Addiction behaviour can only be properly understood within its specific social and environmental ecology. Risk factors for overdose, such as the type of drug consumed, and the route of administration, are known to differ across countries. This paper describes problems associated with ranking and suggests how mortality data might be used in high-level countries aiming at reduction in the number of overdose deaths.

Opioid agonist treatments and heroin overdose deaths in Baltimore, Maryland, 1995-2009

OBJECTIVES

We examined the association between the expansion of methadone and buprenorphine treatment and the prevalence of heroin overdose deaths in Baltimore, Maryland from 1995 to 2009.

METHODS

We conducted a longitudinal time series analysis of archival data using linear regression with the Newey-West method to correct SEs for heteroscedasticity and autocorrelation, adjusting for average heroin purity.

RESULTS

Overdose deaths attributed to heroin ranged from a high of 312 in 1999 to a low of 106 in 2008. While mean heroin purity rose sharply (1995-1999), the increasing number of patients treated with methadone was not associated with a change in the number of overdose deaths, but starting in 2000 expansion of opioid agonist treatment was associated with a decline in overdose deaths. Adjusting for heroin purity and the number of methadone patients, there was a statistically significant inverse relationship between heroin overdose deaths and patients treated with buprenorphine (P = .002).

CONCLUSIONS

Increased access to opioid agonist treatment was associated with a reduction in heroin overdose deaths. Implementing policies that support evidence-based medication treatment of opiate dependence may decrease heroin overdose deaths.

A response to the opioid overdose epidemic: naloxone nasal spray

Opioid overdose morbidity and mortality is recognized to have epidemic proportions. Medical and public health agencies are adopting opioid harm reduction strategies to reduce the morbidity and mortality associated with overdose. One strategy developed by emergency medical services and public health agencies is to deliver the opioid antidote naloxone injection intranasally to reverse the effects of opioids. Paramedics have used this route to quickly administer naloxone in a needle-free system and avoiding needle-stick injuries and contracting a blood-born pathogen disease such as hepatitis or human immunodeficiency virus. Public health officials advocate broader lay person access since civilians are likely witnesses or first responders to an opioid overdose in a time-acute setting. The barrier to greater use of naloxone is that a suitable and optimized needlefree drug delivery system is unavailable. The scientific basis for design and study of an intranasal naloxone product is described. Lessons from nasal delivery of opioid analgesics are applied to the consideration of naloxone nasal spray.

Influence of war on quantitative and qualitative changes in drug-induced mortality in Split-Dalmatia County, Croatia

Aim

To study drug-induced mortality and characteristics of overdose deaths in the war (1991-1995), pre-war (1986-1990), and post-war period (1996-2000) in Split-Dalmatia County.

Methods

We retrospectively searched through Databases of the Department of Forensic Medicine, University Hospital Split, the national register of death records, the archives of the Split-Dalmatia County Police, and the Register of Treated Drug Addicts of the Croatian National Institute of Public Health, covering the period from 1986 to 2000, according to drug poisoning codes IX and X of the International Classification of Diseases. The indicators were statistically analyzed.

Results

There were 146 registered drug-induced deaths, with 136 (93%) deceased being men. The median age of all cases was 27 years (interquartile range 8). Most of them were single (70.6%), unemployed (44.6%), and secondary school graduates (69.2%). In the war period, there were 4.8 times more deaths than in the pre-war period (P = 0.014), and in the post-war period there were 5.2 times more deaths than in the pre-war period (P = 0.008). The most common site of death was the deceased person’s home. The toxicological analyses showed that 59 (61%) deaths were heroin related, alcohol use was found in 62 cases (42.5%), and multi-substance use was found in more than a half of the cases. In 133 (91.1%) cases, deaths were classified as unintentional, whereas 13 (8.9%) were classified as suicides.

Conclusion

The war, along with other risk factors, contributed to unfavorable developments related to drug abuse in Split-Dalmatia County, including the increase in the drug-induced mortality rate.

Mortality among drug users after discharge from inpatient treatment: an 8-year prospective study

BACKGROUND

Drug users who are leaving/completing inpatient medication-free treatment may, like drug users released from prison, have an elevated risk of dying from fatal overdoses. This is mainly explained by their low drug tolerance.

METHODS

Two hundred and seventy-six drug users who had been admitted to 11 inpatient facilities in Norway, were followed prospectively after discharge from treatment during an 8-year period (1998-2006). The following instruments were used: EuropASI, SCL-25 and MCMI II. Information on deaths and causes of death were obtained from the National Death Register.

RESULTS

A total of 36 deaths were registered after discharge from treatment during the observation period, of which 24 were classified as overdose deaths. During the first 4 weeks after discharge six persons died, yielding an unadjusted excess mortality of 15.7 (rate ratio) in this period (CI 5.3-38.3). All were dropouts and all deaths were classified as opiate overdoses. There was no significant association between time in index treatment and mortality after discharge, nor did any background characteristics correlate significantly with elevated mortality shortly after discharge.

CONCLUSIONS

The elevated risk of dying from overdose within the first 4 weeks of leaving medication-free inpatient treatment is so dramatic that preventive measures should be taken. More studies from similar inpatient programmes are needed in order to obtain systematic knowledge about determinants of overdose deaths shortly after leaving treatment, and possible preventive measures.

Problem drug use the public health imperative: what some of the literature says

Background

With more than 200,000 problem drug users is contact with structured treatment services in England the public health imperative behind drug treatment is great. Problem drug use for many is a chronic and relapsing condition, where "cure" is often neither a reasonable or appropriate expectation and it can further be argued that in these circumstances problem drug use is no different from any number of chronic and enduring health conditions that are managed in the health care system and therefore should be conceptualised as such.

Discussion

A public health approach to drug treatment emphasises the need for drug users in or accessing treatment, to reduce their harmful drug use, reduce drug use related risks such as sepsis and overdose and stay alive for longer. However a public health perspective in relation to problem drug use isn't always either apparent or readily understood and to that end there is still a significant need to continue the arguments and debate that treatment and interventions for problem and dependent drug users need to extend beyond an individualistic approach. For the purposes of discussion in this article public and population health will be used interchangeably.

Summary

A recognition and acceptance that a public and population health approach to the management of problem drug users is sound public health policy also then requires a long term commitment in terms of staffing and resources where service delivery mirrors that of chronic condition management.

Randomized controlled trial comparing the effectiveness and safety of intranasal and intramuscular naloxone for the treatment of suspected heroin overdose

AIMS

Traditionally, the opiate antagonist naloxone has been administered parenterally; however, intranasal (i.n.) administration has the potential to reduce the risk of needlestick injury. This is important when working with populations known to have a high prevalence of blood-borne viruses. Preliminary research suggests that i.n. administration might be effective, but suboptimal naloxone solutions were used. This study compared the effectiveness of concentrated (2 mg/ml) i.n. naloxone to intramuscular (i.m.) naloxone for suspected opiate overdose.

METHODS

This randomized controlled trial included patients treated for suspected opiate overdose in the pre-hospital setting. Patients received 2 mg of either i.n. or i.m. naloxone. The primary outcome was the proportion of patients who responded within 10 minutes of naloxone treatment. Secondary outcomes included time to adequate response and requirement for supplementary naloxone. Data were analysed using multivariate statistical techniques.

RESULTS

A total of 172 patients were enrolled into the study. Median age was 29 years and 74% were male. Rates of response within 10 minutes were similar: i.n. naloxone (60/83, 72.3%) compared with i.m. naloxone (69/89, 77.5%) [difference: -5.2%, 95% confidence interval (CI) -18.2 to 7.7]. No difference was observed in mean response time (i.n.: 8.0, i.m.: 7.9 minutes; difference 0.1, 95% CI -1.3 to 1.5). Supplementary naloxone was administered to fewer patients who received i.m. naloxone (i.n.: 18.1%; i.m.: 4.5%) (difference: 13.6%, 95% CI 4.2-22.9).

CONCLUSIONS

Concentrated intranasal naloxone reversed heroin overdose successfully in 82% of patients. Time to adequate response was the same for both routes, suggesting that the i.n. route of administration is of similar effectiveness to the i.m. route as a first-line treatment for heroin overdose.

Patterns of care in patients discharged from acute psychiatric inpatient facilities: a national survey in Italy

OBJECTIVE

To analyze the characteristics of patients scheduled for discharge from acute psychiatric inpatient facilities in Italy, and their pattern of care.

METHODS

Socio-demographic and clinical characteristics, and patterns of care of 1,330 patients discharged from public and private inpatient facilities in Italy were assessed with a standardized methodology during an index period in the year 2004.

RESULTS

About one half of the sample had schizophrenia or bipolar disorder. However, the case-mix differed between public and private facilities, where in-patients had more frequently mood and anxiety disorders. The use of two or more drugs was very common, involving more than 90% of patients and including typically benzodiazepines and antipsychotics. Structured psychosocial treatments were rarely initiated during the hospital stay. Increasing age, male gender, long stay in the facility (>60 days), personality disorder and type of facility were associated with a higher likelihood of being discharged to a community residential facility. Predictors of discharge to another psychiatric facility were increasing age, being single, schizophrenia, personality disorder and organic mental disorder. Families were not involved in decisions about patients' discharge in a significant proportion of cases. University psychiatric clinics and private facilities were less coordinated with the community system of care than General Hospital Psychiatric Units. Referral of patients with substance use disorder to drug addiction services occurred in just 30% of subjects.

CONCLUSIONS

This study provides information on the characteristics and the pattern of care of patients discharged from inpatient facilities in a country that has closed down all its mental hospitals. This information may be relevant for those countries that are affording now the downsizing of MHs, and the expansion of community-based models of care.

Unintentional drug overdose death trends in New Mexico, USA, 1990-2005: combinations of heroin, cocaine, prescription opioids and alcohol

AIMS

To determine the contribution of heroin, prescription opioids, cocaine and alcohol/drug combinations to the total overdose death rate and identify changes in drug overdose patterns among New Mexico subpopulations.

DESIGN

We analyzed medical examiner data for all unintentional drug overdose deaths in New Mexico during 1990-2005. Age-adjusted drug overdose death rates were calculated by sex and race/ethnicity; we modeled overall drug overdose death adjusting for age and region.

FINDINGS

The total unintentional drug overdose death rate in New Mexico increased from 5.6 per 100 000 in 1990 to 15.5 per 100 000 in 2005. Deaths caused by heroin, prescription opioids, cocaine and alcohol/drug combinations together ranged from 89% to 98% of the total. Heroin caused the most deaths during 1990-2005, with a notable rate increase in prescription opioid overdose death during 1998-2005 (58%). During 1990-2005, the 196% increase in single drug category overdose death was driven by prescription opioids alone and heroin alone; the 148% increase in multi-drug category overdose death was driven by heroin/alcohol and heroin/cocaine. Hispanic males had the highest overdose death rate, followed by white males, white females, Hispanic females and American Indians. The most common categories causing death were heroin alone and heroin/alcohol among Hispanic males, heroin/alcohol among American Indian males and prescription opioids alone among white males and all female subpopulations.

CONCLUSIONS

Interventions to prevent drug overdose death should be targeted according to use patterns among at-risk subpopulations. A comprehensive approach addressing both illicit and prescription drug users, and people who use these drugs concurrently, is needed to reduce overdose death.

Comparative toxicology of fatal heroin overdose cases and morphine positive homicide victims

AIMS

To compare the blood toxicology of heroin overdose cases and morphine positive homicide victims.

DESIGN

Analysis of coronial cases.

SETTING

Sydney, Australia. Cases A total of 705 cases of death due to opioid toxicity and 28 morphine positive homicide cases (1 January 1998-31 December 2002).

FINDINGS

There was no significant difference between the median morphine concentrations of the overdose and homicide groups (0.50 versus 0.45 mg/l). The overdose group was more likely to have blood alcohol (OR 3.21) present, but less likely to have methadone (OR 0.26) and cannabis (OR 0.04). There was a significant negative correlation between blood morphine and alcohol concentrations among the overdose group (rho = -0.32), but not among the homicide group (rho = -0.03). Independent predictors of a higher blood morphine concentration were a lower alcohol concentration and a higher methadone concentration.

CONCLUSIONS

Morphine concentrations per se are not diagnostic of overdose. The study confirms the salience of concomitant alcohol consumption in such events.

Cause of death and drug use pattern in deceased drug addicts in Sweden, 2002–2003

Compared with their contemporaries, individuals abusing illicit drugs suffer a higher risk of premature death. In Sweden, a simple protocol for registration of fatalities among abusers of alcohol, pharmaceuticals, illicit drugs, or other substances, has been used by the forensic pathologists since 2001. This routine was introduced to allow for an evaluation of the cause and manner of death, and patterns of abuse among different groups of abusers. We explored the data on drug abusers (i.e. abusers of illicit drugs) subjected to a forensic autopsy 2002-2003. The Swedish forensic pathologists examined 10,273 dead victims during the study period and 7% (743/10,273) of the cases were classified as drug abusers. Toxicological analyses were carried out in 99% (736/743) and illicit drugs were detected in 70% (514/736) of these. On average, 3.8 substances (legal or illegal) were found per case. The most common substances were ethanol and morphine, detected in 43 and 35% of the cases, respectively. When exploring the importance of the different substances for the cause of death, we found that the detection of some substances, such as fentanyl and morphine, strongly indicated a poisoning, whereas certain other substances, such as benzodiazepines more often were incidental findings. In total, 50% (372/743) died of poisoning, whereas only 22% (161/743) died of natural causes. Death was considered to be directly or indirectly due to drug abuse in 47% (346/743), whereas evidence of drug abuse was an incidental finding in 21% (153/743) or based on case history alone in 33% (244/743). We believe that this strategy to prospectively categorize deaths among drug addicts constitutes a simple means of standardizing the surveillance of the death toll among drug addicts that could allow for comparisons over time and between countries.

Seasonality and suicide in Italy: amplitude is positively related to suicide rates

BACKGROUND

Recent studies have reported changes in the time patterns of suicide, with conflicting findings regarding the direction of these changes: data from Italy were investigated to evaluate the influence of recent social and medicine-related changes on the seasonality of suicides in the country.

METHODS

A total of 71,227 male suicides and 26,466 female suicides occurring in Italy from 1974 to 2003 were investigated with harmonic spectral analysis to extract their monthly seasonal dispersion by five-year intervals.

RESULTS

The suicide rates of both males and females showed a rising trend, with an evident peak in the 1987-1994 period and a decrease thereafter. Seasonality of suicides, with a clear peak in spring as against the other seasons, accounted for a statistically significant proportion of total variance: around 40% among males and 39% among females. Seasonality did not change across time in a relevant way; however, an anticipation of the peak was observed in both males and females over time, with amplitude increasing or decreasing as a function of yearly suicide rates.

LIMITATIONS

Data could not be analysed according to age or to the method of suicide, since this information was not available across the whole time interval.

CONCLUSION

The seasonal effect on mortality by suicide is positively related to suicide rates, so much that changes in suicide rates over time correspond to changes in suicide seasonality.

Prescribing naloxone to actively injecting heroin users: a program to reduce heroin overdose deaths

Heroin overdose deaths have increased alarmingly in Chicago over the past decade. Naloxone, an opioid antagonist with no abuse potential, has been used to reverse opiate overdose in emergency medical settings for decades. We describe here a program to educate opiate users in the prevention of opiate overdose and its reversal with intramuscular naloxone. Participant education and naloxone prescription are accomplished within a large comprehensive harm reduction program network. Since institution of the program in January 2001, more than 3,500 10 ml (0.4 mg/ml) vials of naloxone have been prescribed and 319 reports of peer reversals received. The Medical Examiner of Cook County reported a steady increase in heroin overdose deaths since 1991, with a four-fold increase between 1996 and 2000. This trend reversed in 2001, with a 20% decrease in 2001 and 10% decreases in 2002 and 2003.

Variations in respiratory distress characterize the acute agonal period during heroin overdose death: Relevance to postmortem mRNA studies

AIMS

To determine whether there are factors during apparent rapid heroin overdose death that affect agonal state and thus brain pH (index of hypoxia) that can influence neurobiological systems linked to drug abuse.

DESIGN AND METHODS

Brain specimens and autopsy/medical reports were investigated in subjects dying from heroin overdose (n=70) and compared to normal controls (n=45) as well as suicide victims (n=31) with a documented rapid cause of death. Detailed autopsy material was characterized as to positive and negative respiratory distress in relation to brain pH; drug toxicity and other demographic information was also evaluated. In situ hybridization histochemistry was used to study mRNA expression levels of dopamine (e.g., D2 receptor, dopamine transporter) and opioid (e.g., proenkephalin) related markers in various structures in relation to brain pH.

FINDINGS

Brain pH was generally reduced in heroin overdose cases versus normal and suicide subjects. There was, however, significant variation in heroin overdose deaths related to differences in respiratory distress that differentially altered brain pH levels. Various factors such as vomit inhalation, resuscitation, pulmonary embolism and suffocation contributed to positive respiratory distress. Elevated brain pH was observed in heroin overdose with positive alcohol toxicity suggesting potentiated alcohol-induced rapidity of heroin deaths. mRNA expression levels of the dopamine-related genes and proenkephalin were positively correlated with brain pH.

CONCLUSIONS

Respiratory distress contributes to variations in the acute agonal state during heroin overdose death that differentially alters brain pH levels and significantly impacts mRNA levels. Such findings should be considered for postmortem molecular/neurochemical neurobiological studies of opiate abusers.

Recent trends in narcotic deaths

The prevalence of overdose deaths from opioids is still generally increasing throughout the world. Heroin is still the predominant illicit opioid of interest to toxicology laboratories because of its continuing widespread availability and its ability to elicit respiratory depression and coma. In many countries methadone continues to play a major role in cases of drug toxicity because of its large-scale use to treat opioid dependency and its high potency and long duration of action. Increasingly, buprenorphine is being used as an alternative pharmacotherapy, and although apparently safer than methadone, it still has an inherent risk of toxicity when used with CNS depressants such as benzodiazepines or when injected. Morphine continues to be the dominant analgesic; however, oxycodone, hydromorphone, hydrocodone, and fentanyl are increasingly being used and will require increasing efforts by toxicology laboratories to ensure that these substances are adequately covered by testing programs.

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.

Take-home naloxone to reduce heroin death

BACKGROUND

This paper reviews the relevant literature related to the distribution of take-home naloxone.

METHODS

A Medline search was conducted on articles published between January 1990 and June 2004 to identify scientific literature relevant to this subject. Those publications were reviewed, and from them other literature was identified and reviewed.

RESULTS

The prevalence, pathophysiology and circumstances of heroin overdose, and also bystander response are included in this review. Naloxone peer distribution has been instituted to varying degrees in the United States, Italy, Spain, Germany and the United Kingdom.

CONCLUSION

At this point the evidence supporting naloxone distribution is primarily anecdotal, although promising. Although the distribution of naloxone holds promise for further reducing heroin overdose mortality, problems remain. Naloxone alone may be insufficient in some cases to revive the victim, and cardiopulmonary resuscitation (CPR), especially rescue breathing, may also be needed. A second dose of naloxone might be necessary. Complications following resuscitation from overdose may infrequently need in-hospital care. Mortality from injecting without anyone else present will be unaffected by take-home naloxone. Take-home naloxone should be studied in a rigorous scientific manner.

Patterns of opioid and cocaine co-use: a descriptive study in a Canadian sample of untreated opioid-dependent individuals

This study examined prevalence and patterns of co-use of opioids and cocaine in regular users of illicit opioids (N = 729) recruited from 5 Canadian cities. Fifty-seven percent (n = 417) reported having used both opioids and cocaine in the month and week preceding the interview; of these, 73% (n = 304) were able to identify a typical pattern of daily co-use. In a typical day, injectors of opioids and cocaine (n = 119) and injectors of opioids who inhaled cocaine (n = 111) showed stable opioid use but variable cocaine use, which peaked at 21 hr. Overall, 30% of the individuals used both drugs exclusively in a sequential fashion, 35% reported taking opioids and cocaine within the same hour, and 35% reported taking them together at the same time or mixing them. These findings indicate that different individuals display different patterns of opioids and cocaine co-use.

Alterations of the vascular basal lamina in the cerebral cortex in drug abuse: a combined morphometric and immunohistochemical investigation

In drug abusers, white matter hyperintensities, perfusion deficits, and metabolic disturbances are detected by neuroimaging analyses in different brain regions. A specific pattern of involvement or a predominance of a specific brain region cannot be drawn. To examine changes of the cerebral microvasculature as a possible morphological substrate of the neuroimaging findings, brain specimens of 12 polydrug abusers and 8 controls were obtained at autopsy. The basal lamina of blood vessels from the frontal, temporal, parietal, and occipital lobes was analysed by means of immunohistochemistry for collagen type IV. The numerical density of vessels was determined in the gray and white matter, and their staining intensity was rated using a three-point scale. In the gray and white matter of polydrug abusers, the number of vessels showing strong immunoreactivity for collagen type IV was significantly reduced, whereas the number of vessels with mild and moderate immunoreactivity was increased as compared to controls. The total numerical density of vessels was not significantly changed. Our results show a significant reduction in immunoreactivity for collagen type IV in the brains from polydrug abusers compared to controls, which may be due to a thinning of the basal lamina of cerebral vessels. The data of the present study show morphological changes of the basal lamina in the brain of polydrug abusers, which might represent the morphological substrate of a disturbed blood-brain barrier. However, it remains yet to be established if the observed changes are responsible for the alterations seen in different neuroimaging analyses and which drug might be of major pathogenetic significance.

The effect of HIV infection on overdose mortality

OBJECTIVES

To quantify the association of HIV infection with overdose mortality and explore the potential mechanisms.

DESIGN

A prospective cohort study.

METHODS

A total of 1927 actively injecting drug users who were HIV seronegative at baseline, of whom 308 later HIV seroconverted, were followed semi-annually for death from 1988 to 2001. Survival analyses using marginal structural and standard Cox models were used to evaluate the effect of HIV infection on the risk of overdose mortality.

RESULTS

Overdose death rates were higher in HIV-seropositive than HIV-seronegative drug users: 13.9 and 5.6 per 1000 person-years, respectively (P < 0.01). The hazard ratio (HR) was 2.54 [95% confidence interval (CI) 1.47, 4.38] for the marginal structural model and 2.06 (95% CI 1.25, 3.38) for the standard Cox model, both adjusted for demographics, drug injection characteristics, alcohol abuse, substance abuse treatment, and sexual orientation. Adjusting for possible time-varying mediators (i.e. drug use, medical conditions and healthcare access) in extended marginal structural models reduced the effect of HIV on overdose mortality by 30% (HR 1.82, 95% CI 1.01, 3.30). Abnormal liver function was associated with a higher risk of overdose mortality (HR 2.00, 95% CI 1.05, 3.84); adjustment for this further reduced the effect of HIV on overdose mortality.

CONCLUSION

HIV infection was associated with a higher risk of overdose mortality. Drug use behavior, systematic disease and liver damage associated with HIV infection appeared to account for a substantial portion of this association. The data suggest a group to target with interventions to reduce overdose mortality rates.

Unintentional methadone-related overdose death in New Mexico (USA) and implications for surveillance, 1998-2002

AIMS

To determine death rates from methadone over time, to characterize methadone-related death and to discuss public health surveillance of methadone-related death.

DESIGN

We analyzed medical examiner data for all unintentional drug overdose deaths in New Mexico, USA, between 1998 and 2002.

MEASUREMENTS

Age-adjusted death rates for methadone-related death, logistic regression models for likelihood of methadone-related death among all unintentional drug overdose deaths and bivariate comparisons within methadone-related death.

FINDINGS

Of 1120 drug overdose deaths during this period, there were 143 (12.8%) methadone-related deaths; the death rate decreased over the time period, averaging 1.6 per 100,000. Of 143 methadone-related deaths, 22.4% were due to methadone alone, 23.8% were due to methadone/prescription drugs (no illicit drugs), 50.3% were due to methadone/illicit drugs and 3.5% were due to methadone/alcohol. These groups were significantly different in demographics, health history and circumstances of death. Of 79 decedents (55.2%) with a known source of methadone, 68 obtained methadone through a physician prescription (31 for methadone maintenance treatment (MMT), 27 for managing pain and 10 had unknown reason for prescription).

CONCLUSIONS

Methadone-related death rates and the proportion of methadone-related death among all drug overdose deaths decreased in New Mexico from 1998 to 2002. It is important for surveillance of methadone-related death to assess multiple drug causes, not just underlying cause. Also, methadone for pain management must be examined alongside MMT and when possible, methadone co-intoxication should be described in the context of other drugs causing death.

Determinants of overdose incidents among illicit opioid users in 5 Canadian cities

BACKGROUND

Drug overdose is a major cause of death and illness among illicit drug users. Previous research has indicated that most illicit drug users experience nonfatal overdoses and has suggested a variety of factors that are associated with risk of overdose. In this study, we examined the occurrence of and the factors associated with nonfatal overdoses within a Canadian sample of illicit opioid users not enrolled in treatment at the time of study recruitment.

METHODS

Interviewers used a standard questionnaire to collect data on sociodemographic characteristics, drug use, health and health care, experience in the criminal justice system and treatment for drug problems; they also performed standard assessments for mental health and infectious disease. The association between overdose and sociodemographic and drug-use factors was examined with chi(2) and t test analyses; marginally significant variables were examined with logistic regression to determine independent effects.

RESULTS

A total of 679 subjects were interviewed; 651 provided answers sufficient for this analysis. One hundred and twelve (17.2%) of the 651 respondents reported an overdose episode in the previous 6 months. In the logistic regression analysis (after adjustment for sociodemographic factors), homelessness, noninjection use of hydromorphone in the past 30 days and involvement in drug treatment in the past 12 months were predictors of overdose (p < 0.05).

INTERPRETATION

Overdose poses a considerable health risk for illicit opioid users. We found that a diverse set of factors was associated with overdose episodes. Prevention efforts will likely be more effective if they can be directed to specific causal factors.

Distribution of deaths by unintentional illicit drug overdose in Italy based on periodicity over time, 1984-2000

AIM

To assess whether substance-abusing people have a higher risk of dying from unintentional acute intoxication in specific periods of the year.

METHODS

A total of 15,792 deaths (males=14,259; females=1533) were ascertained to be due to unintentional acute intoxication by illicit drugs in Italy in the study period (1984-2000). Distribution of deaths by month was studied with circular statistics techniques, based on the maximization of mean vector length (MMVL) method. The Rayleigh test was used to verify the hypothesis of uniform distribution of the events across some relevant periods. Density estimates for significant periodicities were derived with the kernel method for circular variables.

RESULTS

Over the study period there was a steady increase in the number of deaths by overdose in Italy, affecting both genders, but more evident among males. The monthly distribution of deaths over the study period followed an uneven trend, with a slightly higher risk in the period between December and January, and in August, in both genders. The monthly distribution of deaths due to unintentional acute intoxication by illicit drugs appears influenced by non-casual oscillations following a thrice-yearly cycle, interlaced with a significantly more evident 6-monthly recurrence.

CONCLUSIONS

There does seem to be a higher risk of dying from unintentional overdose in specific periods of the year. Better knowledge of the factors affecting the risk of mortality among substance-abusing people--due to changes in environmental or biological rhythms--could allow prediction of negative events, hence their prevention.