Hair morphine concentrations of fatal heroin overdose cases and living heroin users

Ethanol Reversal of Tolerance to the Respiratory Depressant Effects of Morphine

Opioids are the most common drugs associated with unintentional drug overdose. Death results from respiratory depression. Prolonged use of opioids results in the development of tolerance but the degree of tolerance is thought to vary between different effects of the drugs. Many opioid addicts regularly consume alcohol (ethanol), and post-mortem analyses of opioid overdose deaths have revealed an inverse correlation between blood morphine and ethanol levels. In the present study, we determined whether ethanol reduced tolerance to the respiratory depressant effects of opioids. Mice were treated with opioids (morphine, methadone, or buprenorphine) for up to 6 days. Respiration was measured in freely moving animals breathing 5% CO2 in air in plethysmograph chambers. Antinociception (analgesia) was measured as the latency to remove the tail from a thermal stimulus. Opioid tolerance was assessed by measuring the response to a challenge dose of morphine (10 mg/kg i.p.). Tolerance developed to the respiratory depressant effect of morphine but at a slower rate than tolerance to its antinociceptive effect. A low dose of ethanol (0.3 mg/kg) alone did not depress respiration but in prolonged morphine-treated animals respiratory depression was observed when ethanol was co-administered with the morphine challenge. Ethanol did not alter the brain levels of morphine. In contrast, in methadone- or buprenorphine-treated animals no respiratory depression was observed when ethanol was co-administered along with the morphine challenge. As heroin is converted to morphine in man, selective reversal of morphine tolerance by ethanol may be a contributory factor in heroin overdose deaths.

Heroin-related overdose: The unexplored influences of markets, marketing and source-types in the United States

Heroin overdose, more accurately termed 'heroin-related overdose' due to the frequent involvement of other drugs, is the leading cause of mortality among regular heroin users. (Degenhardt et al., 2010) Heroin injectors are at greater risk of hospital admission for heroin-related overdose (HOD) in the eastern United States where Colombian-sourced powder heroin is sold than in the western US where black 'tar' heroin predominates. (Unick et al., 2014) This paper examines under-researched influences on HOD, both fatal and non-fatal, using data from a qualitative study of injecting drug users of black tar heroin in San Francisco and powder heroin in Philadelphia Data were collected through in-depth, semi-structured interviews carried out in 2012 that were conducted against a background of longer-term participant-observation, ethnographic studies of drug users and dealers in Philadelphia (2007-12) and of users in San Francisco (1994-2007, 2012). Our findings suggest three types of previously unconsidered influences on overdose risk that arise both from structural socio-economic factors and from the physical properties of the heroin source-types: 1) retail market structure including information flow between users; 2) marketing techniques such as branding, free samples and pricing and 3) differences in the physical characteristics of the two major heroin source forms and how they affect injecting techniques and vascular health. Although chosen for their contrasting source-forms, we found that the two cities have contrasting dominant models of drug retailing: San Francisco respondents tended to buy through private dealers and Philadelphia respondents frequented an open-air street market where heroin is branded and free samples are distributed, although each city included both types of drug sales. These market structures and marketing techniques shape the availability of information regarding heroin potency and its dissemination among users who tend to seek out the strongest heroin available on a given day. The physical characteristics of these two source-types, the way they are prepared for injecting and their effects on vein health also differ markedly. The purpose of this paper is to examine some of the unexplored factors that may lead to heroin-related overdose in the United States and to generate hypotheses for further study.

Segmental analysis of amphetamines in hair using a sensitive UHPLC-MS/MS method

A sensitive and robust ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxy methamphetamine in hair samples. Segmented hair (10 mg) was incubated in 2M sodium hydroxide (80°C, 10 min) before liquid-liquid extraction with isooctane followed by centrifugation and evaporation of the organic phase to dryness. The residue was reconstituted in methanol:formate buffer pH 3 (20:80). The total run time was 4 min and after optimization of UHPLC-MS/MS-parameters validation included selectivity, matrix effects, recovery, process efficiency, calibration model and range, lower limit of quantification, precision and bias. The calibration curve ranged from 0.02 to 12.5 ng/mg, and the recovery was between 62 and 83%. During validation the bias was less than ±7% and the imprecision was less than 5% for all analytes. In routine analysis, fortified control samples demonstrated an imprecision <13% and control samples made from authentic hair demonstrated an imprecision <26%. The method was applied to samples from a controlled study of amphetamine intake as well as forensic hair samples previously analyzed with an ultra high performance liquid chromatography time of flight mass spectrometry (UHPLC-TOF-MS) screening method. The proposed method was suitable for quantification of these drugs in forensic cases including violent crimes, autopsy cases, drug testing and re-granting of driving licences. This study also demonstrated that if hair samples are divided into several short segments, the time point for intake of a small dose of amphetamine can be estimated, which might be useful when drug facilitated crimes are investigated.

Evaluation of poly-drug use in methadone-related fatalities using segmental hair analysis

In Denmark, fatal poisoning among drug addicts is often related to methadone. The primary mechanism contributing to fatal methadone overdose is respiratory depression. Concurrent use of other central nervous system (CNS) depressants is suggested to heighten the potential for fatal methadone toxicity. Reduced tolerance due to a short-time abstinence period is also proposed to determine a risk for fatal overdose. The primary aims of this study were to investigate if concurrent use of CNS depressants or reduced tolerance were significant risk factors in methadone-related fatalities using segmental hair analysis. The study included 99 methadone-related fatalities collected in Denmark from 2008 to 2011, where both blood and hair were available. The cases were divided into three subgroups based on the cause of death; methadone poisoning (N=64), poly-drug poisoning (N=28) or methadone poisoning combined with fatal diseases (N=7). No significant differences between methadone concentrations in the subgroups were obtained in both blood and hair. The methadone blood concentrations were highly variable (0.015-5.3, median: 0.52mg/kg) and mainly within the concentration range detected in living methadone users. In hair, methadone was detected in 97 fatalities with concentrations ranging from 0.061 to 211ng/mg (median: 11ng/mg). In the remaining two cases, methadone was detected in blood but absent in hair specimens, suggesting that these two subjects were methadone-naive users. Extensive poly-drug use was observed in all three subgroups, both recently and within the last months prior to death. Especially, concurrent use of multiple benzodiazepines was prevalent among the deceased followed by the abuse of morphine, codeine, amphetamine, cannabis, cocaine and ethanol. By including quantitative segmental hair analysis, additional information on poly-drug use was obtained. Especially, 6-acetylmorphine was detected more frequently in hair specimens, indicating that regular abuse of heroin was common among the deceased. In conclusion, continuous exposure of methadone provide by segmental hair analysis suggested that reduced tolerance of methadone was not a critical factor among methadone-related fatalities. In contrast, a high abundance of co-ingested CNS depressants suggested that adverse effects from drug-drug interactions were more important risk factors for fatal outcome in these deaths.

Patterns and correlates of non-fatal heroin overdose at 11-year follow-up: findings from the Australian Treatment Outcome Study

BACKGROUND

Overdose is a major cause of morbidity and mortality amongst opioid users. This paper reported recent non-fatal overdose amongst the Australian Treatment Outcome Study (ATOS) cohort at 11-year follow-up, and characteristics that predict recent overdose.

METHODS

Longitudinal cohort, with 431 (70.1%) of the original 615 participants interviewed. Participants were administered the ATOS structured interview, addressing demographics, treatment history, drug use, heroin overdose, criminality, health and psychopathology.

FINDINGS

Mean time since heroin initiation was 20.4 years. By 11-year follow-up, the proportion who had overdosed was 67.5%, and 24.4% had experienced five or more overdoses. In the 12 months preceding 11-year follow-up, 4.9% had overdosed (11.8% of those who had used heroin in that period). Of the 21 participants who had recently overdosed, 20 (95.2%) had overdosed previously, and 19 (90.5%) were not enrolled in a treatment programme at the time. Those who had recently overdosed reported higher levels of use of opiates other than heroin (57.1% vs 24.9%), benzodiazepines (61.9% vs 30.5%,), methamphetamine (38.1% vs 16.8%) and cocaine (19.0% vs 3.7%). They also had exhibited higher levels of heroin use and other drug use at baseline, 12 and 24 month follow-ups.

CONCLUSIONS

While the prevalence had declined, overdoses still occurred. A history of overdose and polydrug use patterns continued to provide strong markers for those at continued risk.

Would legalizing illicit opioids reduce overdose fatalities? Implications from a natural experiment

Overdose is the leading cause of premature mortality among heroin users. We examine whether the provision of regulated and quality-controlled heroin to users in specified doses would reduce heroin overdose rates. We also address this in the context of the epidemic of prescription opioid use and deaths seen in recent years in the United States and internationally. We explore the extent to which any change in legal access to heroin would affect overdose rates, and note that this depends upon the validity of the two main assumptions that variations in illicit drug purity and/or the presence of drug contaminants are major causes of overdose. Toxicological and demographic data from studies of heroin overdose deaths do not support these assumptions. The surge in the use of pharmaceutical opioids provides an example of the legal delivery of opioids of known dosage and free of contaminants, where overdose deaths can be examined to test these assumptions. Rates of fatal opioid overdose have escalated, with increased rates of prescribing of pharmaceutical opioids. On the basis of the experience with prescription opioids, unregulated legal heroin access would not reduce overdose rates.

Evaluation of metabolite/drug ratios in blood and urine as a tool for confirmation of a reduced tolerance in methadone-related deaths in Denmark

BACKGROUND

Methadone blood concentrations in fatal cases are highly variable and there is an appreciable overlap between therapeutic methadone concentrations and the concentrations detected in fatalities. As with other opioids, the background of these methadone-related deaths is unclear. The aim of this study was to investigate if short-time abstinence was contributing to the cause of death in methadone-related deaths by evaluation of the EDDP/methadone ratio in blood and urine.

METHODS

Samples of blood and urine were collected from 103 autopsy cases and analysed for the concentrations of methadone and its main metabolite EDDP. The cases were divided into three groups according to the cause of death: cases where methadone was the cause of death (N=67), cases where poly-drug poisoning including methadone was the cause of death (N=24) and cases where death were caused by other factors (N=12). Urine samples from 11 living persons receiving methadone were also included.

RESULTS

In general, a substantial overlap of the methadone concentrations in blood and urine was seen between the groups. There was a tendency of lower median EDDP/methadone urinary ratios in the methadone poisoning group (median: 1.0), poly-drug poisoning group (median: 0.94) and in the fatalities not related to methadone (median: 1.1) compared to the living subjects in methadone treatment (median: 1.6), although the differences were not significant.

CONCLUSION

It was not possible to reveal a possible abstinence period prior to death by using the EDDP/methadone ratio in blood and urine in methadone-related deaths.

Ethanol reversal of cellular tolerance to morphine in rat locus coeruleus neurons

Consumption of ethanol is a considerable risk factor for death in heroin overdose. We sought to determine whether a mildly intoxicating concentration of ethanol could alter morphine tolerance at the cellular level. In rat locus coeruleus (LC) neurons, tolerance to morphine was reversed by acute exposure of the brain slice to ethanol (20 mM). Tolerance to the opioid peptide [d-Ala(2),N-MePhe(4),Gly-ol]-enkephalin was not reversed by ethanol. Previous studies in LC neurons have revealed a role for protein kinase C (PKC)α in μ-opioid receptor (MOPr) desensitization by morphine and in the induction and maintenance of morphine tolerance, but we have been unable to demonstrate that 20 mM ethanol produces significant inhibition of PKCα. The ability of ethanol to reverse cellular tolerance to morphine in LC neurons was absent in the presence of the phosphatase inhibitor okadaic acid, indicating that dephosphorylation is involved. In human embryonic kidney 293 cells expressing the MOPr, ethanol reduced the level of MOPr phosphorylation induced by morphine. Ethanol reversal of tolerance did not appear to result from a direct effect on MOPr since acute exposure to ethanol (20 mM) did not modify the affinity of binding of morphine to the MOPr or the efficacy of morphine for G-protein activation as measured by guanosine 5'-O-(3-[(35)S]thio)triphosphate binding. Similarly, ethanol did not affect MOPr trafficking. We conclude that acute exposure to ethanol enhances the effects of morphine by reversing the processes underlying morphine cellular tolerance.

Reversal of morphine analgesic tolerance by ethanol in the mouse

The chronic use of opioids in humans, accompanied by the development of tolerance, is a dangerous phenomenon in its own right. However, chronic opioid use is often made more dangerous by the coconsumption of other substances. It has been observed that the blood level of opioids in postmortem analyses of addicts, who consumed ethanol along with the opioid, was much less than that observed in individuals who died from opioids alone. This relationship between ethanol and opioids led us to investigate the hypothesis that ethanol alters tolerance to opioids. In the present study, we report that ethanol significantly and dose-dependently reduced the antinociceptive tolerance produced by morphine and the cross-tolerance between [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin (DAMGO) and morphine in the mouse tail-flick test. The reversal of morphine tolerance was partially blocked by both the gamma receptor blocker bicuculline and by the γ-aminobutyric acid (GABA)(B) receptor blocker phaclofen and the administration of both inhibitors completely reversed the effects of ethanol on morphine tolerance. Diazepam, like ethanol, decreased morphine tolerance. However, this inhibition was reversed by the GABA(A) antagonist bicuculline but not by the GABA(B) antagonist phaclofen. These findings have important implications for individuals who abuse opioids and ethanol as well as suggest a mechanism to reduce the amount of opioid needed in chronic pain treatment.

Hair analysis underestimates heroin use in prisoners

The value of hair analysis in measuring treatment outcome was examined in a randomised controlled trial (RCT) of an Australian state prison-based methadone programme between 1997 and 1998 (n = 382 male prisoners). Hair samples were analysed for morphine using immunoassay techniques. Agreement between hair analysis and self-report was tested using kappa, McNemar's test of symmetry and Pearson's correlation coefficient r. Hair analysis based on immunoassay was inadequate as the primary outcome measure for the RCT but had value in supplementing self-reported heroin use. There was a modest correlation (r = 0.31, p < 0.001) between self-reported frequency of heroin use and morphine concentrations in hair. Sectional hair analysis, a reflection of duration of drug use, was uninformative and generally impractical due to the length of hair sections needed.

Withdrawal symptoms as a predictor of mortality in patients HIV-infected through drug use and receiving highly active antiretroviral therapy (HAART)

Even in the highly active antiretroviral therapy (HAART) era, individuals HIV-infected through injecting drug use (IDUs) are at increased risk of death due to the burden of competing events such as liver disease, overdose and suicide. The objective of this study was to explore the role which life events' experience, in particular drug-related events such as detoxification or withdrawal symptoms, may play on the risk of death in HIV-infected IDUs. Our analysis was based on longitudinal data of 296 HIV-infected IDUs from when they started HAART. Data collection included medical records and patient's self-reports detailing, among other information, life events including drug-related problems. Multiple imputations for missing data in the explanatory variables together with Cox models were used to identify predictors of death. During HAART follow-up, 26 deaths occurred, corresponding to 1.8 deaths per 100 person-years. The majority (N=8) were attributable to liver disease while 5 were from unknown causes (found deceased at home or in a car). After adjustment for age and time-dependent viral load (>10,000 cp/ml) individuals experiencing withdrawal symptoms had a fivefold increased risk of death with respect to the others. Withdrawal symptoms in IDUs living with HIV reflect physicians' difficulties in managing their patients' opioid dependence. Early detection and increasing substitution dosages or switching to a more adequate treatment could prevent possible drug-related deaths.

Experience of road and other trauma by the opiate dependent patient: a survey report

Background

Trauma plays an important role in the experience of many patients with substance use disorder, but is relatively under-studied particularly in Australia. The present survey examined the lifetime prevalence of various forms of trauma including driving careers in the context of relevant medical conditions.

Methods

A survey was undertaken in a family medicine practice with a special interest in addiction medicine in Brisbane, Australia.

Results

Of 350 patients surveyed, 220 were substance dependent, and 130 were general medical patients. Addicted patients were younger (mean ± S.D. 33.72 ± 8.14 vs. 44.24 ± 16.91 years, P < 0.0001) and had shorter driving histories (15.96 ± 8.50 vs. 25.54 ± 15.03 years, P < 0.0001). They had less driving related medical problems (vision, spectacle use, diabetes) but more fractures, surgical operations, dental trauma and assaults. Addicted patients also had significantly worse driving histories on most parameters measured including percent with driving suspensions (O.R. = 7.70, C.I. 4.38–13.63), duration of suspensions (1.71 ± 3.60 vs. 0.11 ± 0.31 years, P < 0.0001), number of motor vehicle collisions (2.00 ± 3.30 vs. 1.10 ± 1.32, P = 0.01), numbers of cars repaired (1.73 ± 3.59 vs. 1.08 ± 1.60, P = 0.042), rear end collisions (O.R. = 1.90, CI 1.13–3.25), running away after car crashes (O.R. = 26.37, CI 4.31–1077.48), other people hospitalized (O.R. = 2.00, C.I. 0.93–4.37, P = 0.037) and people killed (17 vs. 0 P = 0.0005). Upon multivariate analysis group membership was shown to be a significant determinant of both cars repaired and cars hit when controlled for length of driving history. Hence use of all types of drugs (O.R. = 10.07, C.I. 8.80–14.72) was more common in addicted patients as were general (O.R. = 3.64, C.I. 2.99–4.80) and road (O.R.= 2.73, C.I. 2.36–3.15) trauma.

Conclusion

This study shows that despite shorter driving histories, addicted patients have worse driving careers and general trauma experience than the comparison group which is not explained by associated medical conditions. Trauma is relevant to addiction management at both the patient and policy levels. Substance dependence policies which focus largely on prevention of virus transmission likely have too narrow a public health focus, and tend to engender an unrealistically simplistic and trivialized view of the addiction syndrome. Reduction of drug driving and drug related trauma likely require policies which reduce drug use per se, and are not limited to harm reduction measures alone.

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.

Patterns of sustained heroin abstinence amongst long-term, dependent heroin users: 36 months findings from the Australian Treatment Outcome Study (ATOS)

AIMS

To determine patterns of past month, 12 month and sustained 36 month heroin abstinence.

METHODS

As part of a longitudinal cohort study, 429 heroin users re-interviewed at 36 month follow-up for the Australian Treatment Outcome Study (ATOS).

RESULTS

The proportion who had sustained heroin abstinence since baseline declined from 14% at 12 months to 8% at 36 months. The proportion who reported abstinence over the preceding 12 months, however, increased significantly from 14% at 12 months to 40% at 36 months. There were no significant gender differences in the proportions reporting sustained 36 month abstinence. Females, however, were significantly more likely to have maintained abstinence over the 12 months preceding 36 month follow-up. Independent predictors of sustained abstinence over 36 months were fewer treatment episodes since baseline, not committing crime at baseline and higher levels of global psychological distress.

CONCLUSIONS

Despite a decline in the proportion who had maintained complete heroin abstinence over 36 months, there were substantial increases in 12 month abstinence patterns. The results illustrate the importance of stable treatment retention.

Morphine and 6-acetylmorphine concentrations in blood, brain, spinal cord, bone marrow and bone after lethal acute or chronic diacetylmorphine administration to mice

The aim of this study was to evaluate postmortem incorporation of opiates in bone and bone marrow after diacetylmorphine (heroin) administration to mice. Mice were given acute (lethal dose of 300 mg/kg) or chronic (10 and 20 mg/kg/24 h for 20 days) intraperitoneal administration of diacetylmorphine. The two metabolites of diacetylmorphine, 6-acetylmorphine (6-AM) and morphine, were extracted from whole blood, brain, spinal cord, bone marrow and bone (after hydrolysis) using a liquid/liquid method. Quantification was performed by gas chromatography-mass spectrometry (GC/MS). Results showed that after acute administration, opiates were present in all studied tissues. Morphine concentrations appeared to be higher than those of 6-AM in blood (52.4 microg/mL versus 27.7 microg/mL, n=12), bone marrow (87.8 ng/mg versus 8.9 ng/mg, n=6) and bone (0.85 ng/mg versus 0.43 ng/mg, n=6), but 6-AM concentrations were higher than those of morphine in brain (14.0 ng/mg versus 7.4 ng/mg, n=12) and spinal cord (27.8 ng/mg versus 20.8 ng/mg, n=12). No correlation was found for both compounds between blood concentrations and either brain, spinal cord, bone or bone marrow concentrations while a significant one was found between brain and spinal cord concentrations either for morphine (r=0.89, n=12, p<0.001) or 6-AM (r=0.93, n=12, p<0.001), the concentration being higher in spinal cord than in brain. When bones were stored for 2 months, only 6-AM remained in bone marrow but not in bone. After chronic administration, mice being sacrificed by cervical dislocation 24 h after the last injection, no opiate was detected in any studied tissues. Further studies are required, in particular in human bones, but these results seem to show that 6-AM could be detect in bone marrow several weeks after the death and could be an alternative tissue for forensic toxicologist to detect a fatal diacetylmorphine overdose, even if no correlation between blood and bone marrow was observed. On the other hand, neither bone tissue nor bone marrow will allow the confirmation of a chronic diacetylmorphine use.

Heroin and cocaine dependence and the risk of accidental non-fatal drug overdose

The relation between illicit drug dependence and the likelihood of drug overdose is unclear. We recruited 1,066 habitual drug users for this analysis through street-based outreach in New York City. In this sample, 99.3% of respondents used heroin in the past year and 87.1% of respondents used cocaine; 819 (77.5%) heroin users and 735 (79.2%) cocaine users were severely dependent on either drug respectively. In multivariable models, among heroin users, persons who were severely heroin dependent were less likely (OR = 0.6; 95% CI = 0.4-0.9) to have overdosed on any drug in the past year; among cocaine users, those who were severely cocaine dependent were more likely (OR = 1.6; 95% CI = 1.0-2.6) to have overdosed in the past year. The relation between illicit drug dependence and risk of overdose may vary for different patterns of drug dependence. These observations suggest that overdose prevention interventions, perhaps even those specifically targeting opiate overdose, may be more efficiently directed at individuals exhibiting cocaine dependence.

Reductions in heroin use are not associated with increases in other drug use: 2-year findings from the Australian Treatment Outcome Study

AIMS

To determine whether reductions in frequency of heroin use were associated with reductions in the use of other drugs over a 24-month period.

DESIGN

Longitudinal cohort, with follow-up at 3, 12 and 24 months.

PARTICIPANTS

Six hundred and fifteen heroin users recruited for the Australian Treatment Outcome Study.

SETTING

New South Wales, Australia.

FINDINGS

The proportion reporting weekly heroin use declined significantly at 3, 12 and 24 months. Reductions in heroin use were associated with longer periods in both residential rehabilitation (RR) and maintenance treatment (MT). Less frequent use of other opioids, cocaine, amphetamine, cannabis and benzodiazepines were noted over follow-up, with alcohol use remaining stable. Across follow-up, lower frequency heroin use was associated with reduced likelihood of frequent use of other opioids, cocaine, amphetamine and benzodiazepines. Alcohol and cannabis use were unrelated to heroin use. Longer periods spent in RR were associated with declines in the use of all other drug classes, with MT associated with declines in other opioid and alcohol use.

CONCLUSIONS

There was no evidence for drug substitution in the face of reduced heroin use in this cohort of treatment seekers. The fear that a successful reduction in heroin use amongst treatment seekers will precipitate an increase in the use of other drugs appears ill-founded.

Systemic disease among cases of fatal opioid toxicity

AIMS

To determine levels of systemic disease among cases of death due to opioid toxicity.

DESIGN

Analysis of coronial cases.

SETTING

Sydney, Australia.

CASES

A total of 841 cases of death due to opioid toxicity (1 January 1998-31 December 2002).

FINDINGS

Ventricular hypertrophy was present in 5.9% of cases and severe coronary artery atherosclerosis in 5.7%. Severe coronary pathology was more pronounced among older cases. Pre-existing bronchopneumonia was present in 13.2% of cases. Hepatic pathology was the most common type of pathology, and was far more marked among older cases. Cirrhosis was present in 25.3% of those aged > 44 years. Levels of renal pathology were comparatively low, but were related significantly to increasing age. Systemic disease in more than one organ system was present in 24.4% of cases, and was related to increasing age (44% of those aged > 44 years). The only pathology for which gender was an independent predictor among opioid cases was ventricular hypertrophy, more common in males.

CONCLUSIONS

Systemic disease, most prominently liver disease, is common among fatal opioid toxicity cases, and may be a factor in understanding the dynamics and age demographics of opioid-related death.

Prescription naloxone: a novel approach to heroin overdose prevention

The mortality and morbidity from heroin overdose have increased in the United States and internationally in the last decade. The lipid solubility allows the rapid deposition of heroin and its metabolites into the central nervous system and accounts for the "rush" experienced by users and for the toxicity. Risk factors for fatal and nonfatal heroin overdoses such as recent abstinence, decreased opiate tolerance, and polydrug use have been identified. Opiate substitution treatment such as methadone or buprenorphine is the only proven method of heroin overdose prevention. Death from a heroin overdose most commonly occurs 1 to 3 hours after injection at home in the company of other people. Numerous communities have taken advantage of this opportunity for treatment by implementing overdose prevention education to active heroin users, as well as prescribing naloxone for home use. Naloxone is a specific opiate antagonist without agonist properties or potential for abuse. It is inexpensive and nonscheduled and readily reverses the respiratory depression and sedation caused by heroin, as well as causing transient withdrawal symptoms. Program implementation considerations, legal ramifications, and research needs for prescription naloxone are discussed.

Evaluation of the role of abstinence in heroin overdose deaths using segmental hair analysis

In the body heroin is rapidly metabolized to 6-acetylmorphine and morphine. Victims of lethal heroin overdose often present with fairly low blood concentrations of morphine. Reduced tolerance due to abstinence has been proposed to account for this finding. The aim of the present study was to examine the role of abstinence in drug-related deaths by comparing recent and past exposure to opioids using segmental hair analysis with the postmortem blood morphine concentrations in deceased heroin users. The study included 60 deceased drug addicts in the Stockholm area, Sweden. In 32 cases, death was not related to heroin intake. In 18 of the 28 heroin fatalities, opioids were absent in the most recent hair segment, suggesting a reduced tolerance to opioids. However, the blood morphine levels were similar to those found in the 10 subjects that showed continuous opioid use. Hair and blood analysis disclosed an extensive use of additional drugs that directly or indirectly may influence the opioid system. The results suggest that abstinence is not a critical factor for heroin overdose death. Obviously tolerant subjects die after intake of similar doses. Other factors, particularly polydrug use, seem to be more causally important for these deaths.

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.

Screening for drugs of abuse in hair with ion spray LC-MS-MS

Analyzing hair for many substances can be tedious and expensive, and a rapid screening method should prove helpful. Generally, screening has been performed using immunological tests, mainly in workplace drug testing, where the number of samples has been high. The aim of this study was to develop an LC-MS-MS method for the simultaneous analysis of several drugs of abuse in human hair as an alternative to immunological screening tests. In 75 randomly selected autopsy cases, hair was analyzed in addition to the usual specimens of blood and urine. The method included nicotine, cotinine, morphine, codeine, 6-acetylmorphine, ethylmorphine, amphetamine, methamphetamine, MDA, MDMA, benzoylecgonine, cocaine, 7-aminoflunitrazepam and diazepam. The LC-MS-MS analysis was performed on a SCIEX API 2000 MS-MS instrument equipped with an electrospray interface. To 20-50 mg of hair, 0.5 ml of mobile phase A (acetonitril:methanol:20 mM formate buffer, pH 3.0 (10:10:80)) and 25 microl of internal standard were added and the sample was incubated in a water bath at 37 degrees C during 18 h. Using a threshold of 20 ng/sample, equivalent to 1 ng/mg if 20mg hair is used, 26 positive results were found in 16 cases. Three of the 26 positive detections could not be confirmed by GC-MS. Two of the cases were not previously known as drug users. Of the 59 negative cases, only one case had a positive blood sample showing 0.01 and 0.07 microg/g femoral blood of 6-acetylmorphine and morphine, respectively. This might indicate drug abstinence resulting in decreased tolerance or even a "first time" use of heroin resulting in death. We conclude that the use of hair analysis in postmortem cases can reveal both unknown drug use, as well as confirm a period of drug abstinence prior to an acute fatal overdose. The proposed LC-MS-MS method showed high sensitivity, was very easy to perform and seemed appropriate for screening purposes.

Screening for drugs of abuse in hair with ion spray LC–MS–MS

Analyzing hair for many substances can be tedious and expensive, and a rapid screening method should prove helpful. Generally, screening has been performed using immunological tests, mainly in workplace drug testing, where the number of samples has been high. The aim of this study was to develop an LC-MS-MS method for the simultaneous analysis of several drugs of abuse in human hair as an alternative to immunological screening tests. In 75 randomly selected autopsy cases, hair was analyzed in addition to the usual specimens of blood and urine. The method included nicotine, cotinine, morphine, codeine, 6-acetylmorphine, ethylmorphine, amphetamine, methamphetamine, MDA, MDMA, benzoylecgonine, cocaine, 7-aminoflunitrazepam and diazepam. The LC-MS-MS analysis was performed on a SCIEX API 2000 MS-MS instrument equipped with an electrospray interface. To 20-50 mg of hair, 0.5 ml of mobile phase A (acetonitril:methanol:20 mM formate buffer, pH 3.0 (10:10:80)) and 25 microl of internal standard were added and the sample was incubated in a water bath at 37 degrees C during 18 h. Using a threshold of 20 ng/sample, equivalent to 1 ng/mg if 20mg hair is used, 26 positive results were found in 16 cases. Three of the 26 positive detections could not be confirmed by GC-MS. Two of the cases were not previously known as drug users. Of the 59 negative cases, only one case had a positive blood sample showing 0.01 and 0.07 microg/g femoral blood of 6-acetylmorphine and morphine, respectively. This might indicate drug abstinence resulting in decreased tolerance or even a "first time" use of heroin resulting in death. We conclude that the use of hair analysis in postmortem cases can reveal both unknown drug use, as well as confirm a period of drug abstinence prior to an acute fatal overdose. The proposed LC-MS-MS method showed high sensitivity, was very easy to perform and seemed appropriate for screening purposes.

Postmortem toxicology of drugs of abuse

Conducting toxicology on post-mortem specimens provides a number of very significant challenges to the scientist. The range of additional specimens include tissues such as decomposing blood and other tissues, hair, muscle, fat, lung, and even larvae feeding on the host require special techniques to isolate a foreign substance and allow detection without interference from the matrix. A number of drugs of abuse are unstable in the post-mortem environment that requires careful consideration when trying to interpret their significance. Heroin, morphine glucuronides, cocaine and the benzodiazepines are particularly prone to degradation. Moreover, redistributive process can significantly alter the concentration of drugs, particularly those with a higher tissue concentration than the surrounding blood. The designer amphetamines, methadone and other potent opioids will increase their concentration in blood post-mortem. These processes together with the development of tolerance means that no concentration of a drug of abuse can be interpreted in isolation without a thorough examination of the relevant circumstances and after the conduct of a post-mortem to eliminate or corroborate relevant factors that could impact on the drug concentration and the possible effect of a substance on the body. This article reviews particular toxicological issues associated with the more common drugs of abuse such as the amphetamines, cannabinoids, cocaine, opioids and the benzodiazepines.

Comparison of acute lethal toxicity of commonly abused psychoactive substances

AIMS

To determine the acute lethal toxicity of a range of psychoactive substances in terms of the dose customarily used as a single substance for non-medical purposes.

DESIGN AND METHOD

A structured English-language literature search was conducted to identify experimental studies and clinical reports that documented human and non-human lethal doses of 20 abused substances that are distributed widely in Europe and North America. Four inclusion criteria were specified for the reports, and approximately 3000 relevant records were retrieved from search engines at Biosis, Science Citation Index, Google and the National Library of Medicine's Gateway. In order to account for different drug potencies, a 'safety ratio' was computed for each substance by comparing its reported acute lethal dose with the dose most commonly used for non-medical purposes.

FINDINGS

The majority of published reports of acute lethal toxicity indicate that the decedent used a co-intoxicant (most often alcohol). The calculated safety ratios varied between substances by more than a factor of 100. Intravenous heroin appeared to have the greatest direct physiological toxicity; several hallucinogens appeared to have the least direct physiological toxicity.

CONCLUSIONS

Despite residual uncertainties, the substantial difference in safety ratios suggests that abused substances can be rank-ordered on the basis of their potential acute lethality.

Social network correlates of self-reported non-fatal overdose

The leading cause of death among heroin users is drug overdose. The present study examined the relationship between history of self-reported drug overdoses and social network characteristics among cocaine and opiate users. Data were from cross-sectional surveys administered from March 2001 through February 2003 as part of follow-up of an experimental network oriented HIV prevention intervention. A total of 838 participants with histories of cocaine and opiate use completed the survey. Several social network variables were found to be significantly associated with drug overdose in the prior 2 years, including larger number of network members who were injection drug users and a larger number of conflictual ties among the network members. Even after controlling for age, gender, frequency of injection drug and alcohol use, and health status, network variables continued to have a strong association with history of recent overdose. These data suggest that large drug networks should be targeted for drug overdose prevention interventions.

Alcohol and non-fatal drug overdoses

The purpose of this study was to explore to what extent alcohol is a factor in non-fatal overdoses on the basis of records of ambulance emergencies, and to what extent this varies across gender and age. Furthermore, we wanted to investigate whether alcohol intake, in relation to an overdose, is associated with the risk of recurrent overdoses, and if so, whether such an association varies across gender and age. To investigate the role of alcohol intake in non-fatal overdoses, analyses were conducted both at the event level and at the individual level. Bivariate associations were explored in table analyses and by comparisons of means. To determine whether alcohol intake was associated with experiencing recurrent overdoses, survival analyses were conducted applying Kaplan-Meier estimation and Cox regression models. Furthermore, a linear regression model was estimated to assess the impact of gender age and number of overdoses on the proportion of overdoses in which alcohol was involved. Between groups of clients who had overdosed once, several times or many times, we found that there was a U-shaped relationship. The proportion of overdoses with alcohol involved was highest among those who had overdosed once and those who had overdosed more than ten times. The probability for a recurrent overdose was higher among those who were reported with no alcohol intake in the first overdose. Being female and having alcohol involved in the first overdose registered during our observation period reduced the risk for a recurrent overdose. However, age seemed to be a gradient with respect to alcohol's association with recurrent overdoses. While alcohol was associated with a significantly lower risk for recurrence in the two youngest age groups, this is not the case in the oldest age group. A possible explanation might be that it is a change in the pattern of drug use as an effect of aging where infrequent heroin use in combination with frequent alcohol intake increases with increasing age. For this type of drug users the individual's risk of recurrent overdoses may be lower due to fewer events of heroin intake.

Heroin overdose: research and evidence-based intervention

Drug overdose is a major cause of premature death and morbidity among heroin users. This article examines recent research into heroin overdose to inform interventions that will reduce the rate of overdose death. The demographic characteristics of overdose cases are discussed, including factors associated with overdose: polydrug use, drug purity, drug tolerance, routes of administration, and suicide. Responses by heroin users at overdoses are also examined. Potential interventions to reduce the rate of overdose and overdose-related morbidity are examined in light of the emerging data in this field.