Deaths from methadone use

Prescribed and Diverted Methadone Toxicity in South Australia: An Update

ABSTRACT

Methadone is one of the most common medications currently prescribed for the treatment of opioid use disorders (OUDs). While methadone maintenance programs (MMPs) have been highly successful in the management and treatment of OUDs resulting in a reduced number of fatalities, the risk of overdose/toxicity remains. The current study was undertaken to analyze trends in overdoses attributed to prescribed and diverted methadone in South Australia (SA) between 2000 and 2019. Over the 20-year period, 344 methadone-related deaths occurred in SA with a significant increase in deaths over the study period ( P = 0.03). The mean age of decedents was 42.5 years with a male to female ratio of 1.8:1, with approximately 20% of decedents enrolled in a MMP at the time of death. Overall, only 5.2% of cases demonstrated methadone diversion, which was associated with methadone prescribed for chronic pain and was most likely to be diverted from a friend/housemate or a partner. However, the source of methadone in more than half of cases was unknown, so this is likely a significant underestimate of actual MMP methadone diversion and total methadone diversion.

Characteristics of methadone-related fatalities in Norway

There are currently over 7000 patients enrolled in opioid maintenance treatment (OMT) programs in Norway. A rise in methadone-related deaths proportional to increasing methadone sales over the period 2000-2006 has been observed, but the causative factors for these fatalities have been elusive. In the present study, individual characteristics, methadone concentrations and additional toxicological findings were analyzed. Methadone intoxication deaths (n = 264) were divided into 3 groups according to toxicological findings in whole blood: group 1 - methadone detected alone, or together with one additional drug at low or therapeutic levels, or a low concentration of ethanol (<1 g/L) (n = 21); group 2 - multiple additional drugs/substances detected below lethal levels (n = 175); group 3 - one or more additional drugs/substances detected at lethal levels, or ethanol >3 g/L (n = 55). Methadone blood concentrations in decedents who had been enrolled in OMT were higher than for decedents not in treatment, in all groups. Blood methadone concentrations around 1 mg/L were present in fatal multi-drug intoxications in OMT patients. Results suggest that some patients may be at risk of dying when combining therapeutic concentrations of methadone with other psychoactive substances. Somatic disease was a common finding among deceased OMT patients. Concentrations in methadone users not enrolled in OMT were predominantly between 0.3 and 0.4 mg/L and were not related to the presence of other drugs. However, methadone concentrations below 0.1 mg/L may be associated with intoxication following methadone use, both alone and in combination with other drugs. Younger male users (mean age 34 years) seemed to have a higher susceptibility to methadone intoxication.

Use of hair testing to determine methadone exposure in pediatric deaths

A case of death attributed to methadone acute poisoning in an infant aged 11 months is reported. A sudden infant death syndrome (SIDS) was suspected, whereas a traumatic cause of death was excluded regarding autopsy findings. Specimens were submitted to a large toxicological analysis, which included ethanol measurement by HS-GC-FID, a targeted screening for drugs of abuse and various prescription drug classes followed by quantification using UPLC-MS/MS methods. Methadone and its metabolite (EDDP) were detected in all the tested fluids, as well as in hair, with a blood concentration of methadone considered as lethal for children (73 ng/mL). The cause of death was determined to be acute "methadone poisoning", and the manner of death was "accidental". A discussion of the case circumstances, the difficulties with the interpretation of toxicological findings in children (blood concentration and hair testing), and the origin of exposure are discussed.

Parental substance abuse and accidental death in children

In this report, the authors present two cases of accidental death in children of addicted parents. In the first case, the child was left unattended at home while the mother went out to buy cocaine. She was arrested and detained with no mention of the unsupervised child. The cause of death in this case was determined to be starvation and dehydration. In the second case, a child mistakenly received a methadone suppository by her father instead of an antipyretic suppository. Toxicological analysis of the femoral blood revealed methadone at a concentration of 1.2 mg/L. The cause of death was determined to be methadone intoxication. The literature is reviewed and discussed. We report these cases to illustrate the risk of harm to children from illicit drugs and prescription medications at home and because there is no mention of accidental death in children following a methadone suppository administration in the current literature.

Hepatitis infection in the treatment of opioid dependence and abuse

Many new and existing cases of viral hepatitis infections are related to injection drug use. Transmission of these infections can result directly from the use of injection equipment that is contaminated with blood containing the hepatitis B or C virus or through sexual contact with an infected individual. In the latter case, drug use can indirectly contribute to hepatitis transmission through the dis-inhibited at-risk behavior, that is, unprotected sex with an infected partner. Individuals who inject drugs are at-risk for infection from different hepatitis viruses, hepatitis A, B, or C. Those with chronic hepatitis B virus infection also face additional risk should they become co-infected with hepatitis D virus. Protection from the transmission of hepatitis viruses A and B is best achieved by vaccination. For those with a history of or who currently inject drugs, the medical management of viral hepatitis infection comprising screening, testing, counseling and providing care and treatment is evolving. Components of the medical management of hepatitis infection, for persons considering, initiating, or receiving pharmacologic therapy for opioid addiction include: testing for hepatitis B and C infections; education and counseling regarding at-risk behavior and hepatitis transmission, acute and chronic hepatitis infection, liver disease and its care and treatment; vaccination against hepatitis A and B infection; and integrative primary care as part of the comprehensive treatment approach for recovery from opioid abuse and dependence. In addition, participation in a peer support group as part of integrated medical care enhances treatment outcomes. Liver disease is highly prevalent in patient populations seeking recovery from opioid addiction or who are currently receiving pharmacotherapy for opioid addiction. Pharmacotherapy for opioid addiction is not a contraindication to evaluation, care, or treatment of liver disease due to hepatitis virus infection. Successful pharmacotherapy for opioid addiction stabilizes patients and improves patient compliance to care and treatment regimens as well as promotes good patient outcomes. Implementation and integration of effective hepatitis prevention programs, care programs, and treatment regimens in concert with the pharmacological therapy of opioid addiction can reduce the public health burdens of hepatitis and injection drug use.

Interpretation of lesions of the cardiac conduction system in cocaine-related fatalities

This study examines cases of chronic drug users who died suddenly after drug administration. Victims were young subjects, aged from 19 to 35 from Switzerland and known to the police as long-term drug users. The circumstances of death suggested the occurrence of a sudden, unexpected death. Some victims were undergoing methadone treatment. In each case, a forensic autopsy and toxicological analyses were performed at the Institute of Forensic Medicine in Lausanne in Switzerland between 2002 and 2004, including hair analysis as a means to establish chronic drug use in general, and cocaine use in particular. The conduction system was examined histologically and cases showing potentially lethal changes were chosen for this report. The most frequent lesions found were severe thickening of the atrioventricular node artery, intranodal and perinodal fibrosis, and microscopic foci of chronic inflammatory infiltration. The authors conclude that pathological lesions in the conduction tissue may play a role in the occurrence of death attributed to intoxication consecutive to cocaine ingestion.

The role of methadone in drug-related deaths in the west of Scotland

AIMS

To determine the incidence of methadone as either the principal cause of death or as a contributing factor in drug related deaths in the Strathclyde Police region of Scotland and to assess the impact of supervised consumption of methadone on the number of deaths that occurred within each health board area within this region.

DESIGN

Retrospective analysis of records held within the Department of Forensic Medicine and Science based at the University of Glasgow over the 11-year period 1991-2001.

SETTING

The Strathclyde Police region of Scotland (population approximately 2.25 million).

FINDINGS

In 1991, there was one death recorded which was attributable to methadone. Following the introduction of the methadone maintenance programme (MMP) in Glasgow during 1994, there was a 100% increase in these deaths compared to the previous year, a trend which continued over the subsequent 2 years. Following a confidential enquiry into these deaths and a greater compliance from pharmacies supervising methadone consumption, deaths involving methadone had decreased by 48% in 1997. This was particularly evident in the Greater Glasgow Health Board Area, where methadone prescribing has continued to rise annually. However, some difficulties still exist. Multiple take home doses are sometimes prescribed when a pharmacy is closed, which may lead to inadvertent overdose or facilitate diversion of legitimate supplies. In addition, continued use of heroin was found in approximately one-fifth of MMP patients, suggesting possible underdosing.

CONCLUSIONS

A growing prevalence of heroin misuse has resulted in an increase in the number of individuals entering the MMP. Despite a continuing increase in the amount of methadone prescribed, methadone deaths in Strathclyde have decreased since 1996 due possibly to changes in both prescribing and clinical care. With efficient management to establish that the patient is complying with the guidelines of the programme and has stopped heroin misuse, methadone can be a safe drug for substitution therapy.

Methadone and its role in drug-related fatalities in Cologne 1989-2000

All drug-associated deaths from 1989 to 2000 were analysed at the Institute of Forensic Medicine in Cologne. Information concerning sex, gender, drug consumption, time, place and circumstances of death were analysed. A number of 605 cases were recorded; in 518 cases a toxicological analysis was possible and in 171 an autopsy was performed. When it was possible to determine the cause of death form the information available, acute drug intoxication was recorded in 65%. Heroin head the list of identified substances. Sixty-three percent of the specimens showed a combination of several substances, especially a combination of morphine, benzodiazepines, other medications and alcohol. In comparison with other studies the percentage of methadone-positive specimens is low, even though the proportion of specimens positive for methadone increased from 1989 to 2000. This analysis is discussed using background information concerning the management of substitution therapy and the available literature.

Trends in drug overdose deaths in England and Wales 1993-98: methadone does not kill more people than heroin

AIMS

To test the hypothesis that methadone is responsible for a greater increase in overdose deaths than heroin, and causes proportionally more overdose deaths than heroin at weekends.

DESIGN AND SETTING

Multivariate analysis of 3961 death certificates mentioning heroin, morphine and/or methadone held on the Office for National Statistics drug-related poisoning mortality database from 1993 to 1998 in England and Wales.

MEASUREMENTS

Percentage increase in deaths by year by drug, odds ratio (OR) of dying at the weekend from methadone-related overdose compared to dying from heroin/morphine overdose.

FINDINGS

From 1993 to 1998, annual opiate overdose deaths increased from 378 to 909. There was a 24.7% (95% confidence interval (CI) 22-28%) yearly increase in heroin deaths compared to 9.4% (95% CI 6-13%) for methadone only. This difference was significant (P < 0.001 by test of interaction) after adjustment for sex, age group, polydrug use, area of residence and underlying cause of death. The largest number of deaths occurred on Saturday (673). The OR of death from methadone overdose on Saturday and Sunday was 1.48 (95% CI 1.29-1.71) for methadone-only deaths compared to dying from heroin/morphine at the weekend after adjustment for other covariates, but the OR was not significant (1.09, 95% CI 0.95-1.25) if the weekend was defined as Friday and Saturday.

CONCLUSIONS

There was no evidence that the threefold increase in deaths over time was due to methadone. There was equivocal support only for the hypothesis that there was an excess of deaths from methadone at weekends. Increased interventions to prevent overdose among injectors in England and Wales are long overdue.

Methadone dose and post-mortem blood concentration

The relationship of methadone dose with post-mortem blood concentration was investigated using data collected from 1994 coronial cases in the Australian state of New South Wales. Data on 31 subjects were summarized using linear regression. The weight-adjusted methadone dose, gender, methadone maintenance treatment status and its interaction with adjusted-dose were all significant predictors of post-mortem blood methadone concentration. Data on the death of a young man from the toxic effects of three daily doses of 30 mg methadone are used to give an example of a pair of observed (0.74 mg/l) and predicted (0.48 mg/l) post-mortem blood concentrations. The estimated post-mortem blood concentration for male maintenance patients is at least twice the trough plasma levels estimated from previously published studies of living maintenance patients. The estimated post-mortem blood concentration for female maintenance patients is at least three times the estimated trough level of living subjects. We conclude that post-mortem methadone redistribution is probably the principal cause of the observed differences between males and females in post-mortem blood concentrations and the differences between estimated concentrations for living and deceased subjects.

Flunitrazepam variably alters morphine, buprenorphine, and methadone lethality in the rat

Opiates and substitution products are frequently abused, alone and in association with benzodiazepines. While this combination may result in severe respiratory depression and death, the quantitative relationship remains uncertain. We performed randomized, blinded intravenous median lethal dose (MLD) studies in Sprague-Dawley rats of morphine, buprenorphine, and methadone, alone and in combination with intraperitoneal flunitrazepam pretreatment. We employed the up-and-down method, performed in quadruplicate, comparing time to death following opioid injection. Results are expressed as median of four series (extremes). The MLDs of morphine, buprenorphine, and methadone alone were 64.0 (33.6:79.5), 234.6 (168.6:284.4), and 22.5 (19.3:24.1) mg/kg, respectively, and 60.6 (35.2:88.2), 38.4 (30.6:54.0), and 13.0 (9.7:13.8) mg/kg, respectively, after pretreatment with 40 mg/kg flunitrazepam. Times to death for morphine, buprenorphine, and methadone alone were 2.5 (0.8:24), 0.02 (0.0:24), and 2.0 (0.0:24) hours, respectively, and 13.5 (0.0:144), 24.0 (0.0:120), and 0.0 (0.0:24) hours, respectively, after pretreatment with flunitrazepam 40 mg/kg, ip. Flunitrazepam significantly altered methadone (P=0.02) and buprenorphine (P=0.02) but not morphine lethality (P=0.77). Flunitrazepam significantly prolonged time to death only for buprenorphine (P<0.01). Flunitrazepam-opioid drug-drug interactions are more complex than is generally believed. Mechanistic studies of flunitrazepam-opioid lethal interactions are needed.

Toxicologic analysis in cases of possible sudden infant death syndrome: a worthwhile exercise?

The diagnosis of sudden infant death syndrome (SIDS) is one of exclusion. At the Department of Forensic Medicine, Westmead Hospital, toxicologic analysis is performed as part of the postmortem examination of all apparent SIDS deaths. The results for the 5-year period January 1, 1994, to December 31, 1999, were audited to determine whether such routine testing was worthwhile. During this time there were 117 cases with a history consistent with SIDS. Drugs were detected in 19 (16%) of these cases. In 1 case, death was attributed to the finding of methadone. The presence of methadone was regarded as a possible contributing factor to death in a further 2 cases. The presence of possible methadone toxicity had not been expected from the history given before the examination in these 3 cases. In 114 cases there was a suitable sample for alcohol testing; in no case was alcohol detected. In 13 cases the postmortem examination revealed an anatomic cause of death (including 3 cases consistent with whiplash/shaken baby/impact head injury), which excluded a diagnosis of SIDS. In conclusion, routine toxicologic testing in all possible cases of SIDS death supplements the postmortem examination in excluding cases of non-SIDS.

Methadone maintenance programs--a two-edged sword?

Retrospective review was undertaken of all autopsies in which methadone was detected at the Forensic Science Centre, South Australia, during a 3-year period from July 1996 to June 1999. Thirty-five cases were found in which methadone had either caused or contributed to death (age range = 14-54 years; average = 31 years; M:F = 3.4:1). Ten victims were participating in a methadone maintenance program, of whom four died within a week of enrollment. Eight victims (23%) not enrolled in a methadone maintenance program were found who had died after the use of "diverted" methadone (i.e., prescribed for someone else) (age range = 14-34 years; average = 25 years; M:F = 6:2). Deaths were directly attributable to methadone toxicity in seven of the eight cases, with additional drugs or alcohol being found in seven cases. Prevention of ongoing deaths caused by methadone diversion could be achieved by allowing only daily releases of methadone, with the addict having to consume the drug under close supervision.

Methadone deaths: a toxicological analysis

AIMS

To perform a toxicological analysis of deaths involving methadone and to determine the fatal concentration of methadone in such deaths.

METHODS

Deaths in which methadone was mentioned in the cause of death were identified. Deaths were divided into those associated with methadone only and deaths in which the cause of death was a combination of methadone and other drugs. Toxicological findings in these deaths were analysed and compared with previously published data.

RESULTS

One hundred and eleven cases were analysed. In 55 cases, methadone poisoning was given as the sole cause of death. Fifty victims were adults, age range 17-51 years (median, 23), with five victims under 14 years of age. The mean methadone concentration in the adult deaths was 584 micrograms/litre (median, 435; range, 84-2700). In 56 cases, age range 15-49 years, (median, 28), death was ascribed to a combination of methadone and other drugs. The mean methadone concentration in these deaths was 576 micrograms/litre (median, 294; range, 49-2440). In 26 cases, multiple site sampling was performed. This revealed that there could be a 100% discrepancy between methadone concentrations, and other drugs, in samples collected in different sites in the same body.

CONCLUSIONS

There is an overlap between quoted therapeutic methadone concentrations and methadone concentrations seen in fatalities. However, those dying from methadone poisoning might not be the same as those in a methadone programme. A degree of caution must be exercised in determining a fatal concentration because of the phenomenon of postmortem redistribution. Pathologists and toxicologists need to examine all the available postmortem findings in identifying the cause of death.

A risk-benefit analysis of methadone maintenance treatment

Methadone maintenance treatment for heroin (diamorphine) addiction has been extensively researched. There is consistent evidence that while in treatment, heroin addicts are at a lower risk of death, are less involved in crime, and feel and function better than while using heroin. Despite the research evidence supporting methadone treatment, there remains widespread public scepticism about this form of treatment. This scepticism is frequently expressed in terms of the perceived risks of methadone treatment. The perceived risk that methadone treatment may maintain people in an addicted lifestyle is not supported by research literature. The risks of treatment include an increased risk of death during induction into treatment, and risks of diversion of drugs to the black market. For some patients, adverse effects of methadone pose a problem and the availability of new pharmacotherapies may provide useful options for these patients. Risks can be reduced and benefits increased by directing greater attention to the quality of treatment.

Methadone: where are we now?

Methadone is now widely used as opioid replacement therapy because it reduces crime and prevents spread of disease by the intravenous route. However, it is potentially toxic, especially to drug naive patients, and requires careful prescribing.

Mortality associated with New South Wales methadone programs in 1994: lives lost and saved

OBJECTIVES

To estimate the effects of methadone programs in New South Wales on mortality. DESIGN AND CASES: Retrospective, cross-sectional study of all 1994 New South Wales coronial cases in which methadone was detected in postmortem specimens taken from the deceased. Cases were people we identified as patients in NSW methadone maintenance programs or those whose deaths involved methadone syrup diverted from maintenance programs.

OUTCOME MEASURES

Relative risks of fatal, accidental drug toxicity in the first two weeks of treatment and later; the number of lives lost as a result of maintenance treatment; preadmission risks and the number of lives saved by maintenance programs, calculated from data from a previous study.

RESULTS

There was very close agreement between this study's classifications and official pathology reports of accidental drug toxicity. The relative risk (RR) of fatal accidental drug toxicity for patients in the first two weeks of methadone maintenance was 6.7 times that of heroin addicts not in treatment (95% CI RR, 3.3-13.9) and 97.8 times that of patients who had been in maintenance more than two weeks (95% CI RR, 36.7-260.5). Despite 10 people dying from iatrogenic methadone toxicity and diverted methadone syrup being involved in 26 fatalities. In 1994, NSW maintenance programs are estimated to have saved 68 lives (adjusted 95% CI, 29-128).

CONCLUSIONS

In 1994, untoward events associated with NSW methadone programs cost 36 lives in NSW. To reduce this mortality, doctors should carefully assess and closely monitor patients being admitted to methadone maintenance and limit the use of takeaway doses of methadone.