Buprenorphine deaths confirmed by toxicology reveal a low proportion of opioid agonist treatment before death in Finland.

We studied opioid agonist treatment (OAT) status before buprenorphine-related death in Finland, where buprenorphine is the principal OAT medicine and also the most misused opioid, through a retrospective population-based study using medico-legal cause-of-death investigation and OAT patient records. The study included all death cases (N = 570) between 2018 and 2020 with a buprenorphine or norbuprenorphine finding in post-mortem toxicology and with known drug misuse history or concomitant findings of illicit drugs. Of the deceased, 10% had received OAT in the year before death. Less than 1% of individuals < 25 years had received OAT, whereas the proportion in individuals ≥ 25 years was 13% (p < 0.001). There were significantly more females and more fatal poisonings (p < 0.001) among those < 25 years than among those ≥ 25 years. OAT medication at the time of death was sublingual buprenorphine-naloxone in 74% and subcutaneous buprenorphine in 23%. Except for significantly fewer benzodiazepine findings among those receiving OAT, minimal differences were found in terms of age, gender, cause and manner of death, or concomitant substance use between the deceased in and outside of OAT. Concomitant misuse of benzodiazepines, psychostimulants, alcohol, and gabapentinoids was frequent both in and outside of OAT and likely contributed to the death. These results suggest that access to OAT especially for young people and treatment of multiple addictions should be improved. Comprehensive information from medico-legal cause-of-death investigation as a starting point, combined with subsequent ante-mortem patient records, proved to be a successful approach to shed light on the Finnish scene of buprenorphine mortality.

Benzodiazepines and alcohol are associated with cases of fatal buprenorphine poisoning.

BACKGROUND: Although buprenorphine therapy has proved to be successful in opioid maintenance treatments, the drug is also widely abused in many countries by intravenous injection or sniffing ("snorting"). In Finland, buprenorphine is the most important abused opioid causing fatal poisonings. PURPOSE: To evaluate the drug and alcohol findings as well as the cause and manner of death in all buprenorphine-related post-mortem cases for the age group 14-44 years in Finland from 2000 to 2008. METHOD: This was a retrospective analysis of data on opioid-associated deaths in the Finnish comprehensive postmortem toxicology database based on medico-legal autopsies, case background information and laboratory analyses. RESULTS: Buprenorphine was found in 29% of all 1,363 opioid-positive cases, and buprenorphine poisoning was the cause of death in 182 cases out of 391 buprenorphine-positive cases (47%). In these fatal poisonings, the blood buprenorphine/norbuprenorphine concentration ratio was significantly higher than in cases with other causes of death. The manner of death in buprenorphine poisonings that were almost exclusively accidental differed significantly from other buprenorphine-related cases, which also involved diseases and suicides. Death was immediate in 10% of fatal buprenorphine poisonings, was delayed, during sleep, in 52%, and followed an unknown course of events in 38%. In immediate poisonings, the median blood buprenorphine concentration (3.0 µg/l) was significantly higher than that in delayed poisonings (1.2 µg/l). In most buprenorphine poisonings (92%), no opioids other than buprenorphine were involved, but benzodiazepines and alcohol were found in 82 and 58% of cases, respectively. The median concentrations of opioids and benzodiazepines in buprenorphine poisonings were in the therapeutic range. Only one fatal poisoning was found in which neither alcohol nor drugs other than buprenorphine were found. CONCLUSION: A fatal buprenorphine poisoning is typically accidental, and the average victim is a 27-year-old male addict. Circumstantial and environmental factors seem to be crucial in determining the outcome of the poisoning.

Integrated care model and point of care diagnostics facilitate Hepatitis C treatment among patients receiving opioid agonist therapy: a retrospective review of medical records.

BACKGROUND: Hepatitis C virus (HCV) is common among individuals in opioid agonist therapy (OAT). HCV treatment has previously been unavailable for most HCV positive OAT patients in Finland. The removal of treatment restrictions and attempts to reach HCV elimination goals have increased the number of OAT patients needing HCV treatment. The objectives of this study were 1) to characterize Finnish HCV positive OAT patients and evaluate their eligibility for HCV treatment at addiction service units, and 2) to retrospectively review the outcomes of treated patients. METHODS: The study focused on HCV positive OAT patients (n = 235). Demographics and clinical parameters were retrospectively reviewed using the patients' medical records. The eligibility of providing HCV treatment to patients at addiction service units were evaluated based on patients' clinical characteristics, such as liver function and patterns of substance use. The outcomes of patients receiving HCV treatment were reviewed. RESULTS: Of HCV antibody positive OAT patients, 75% had chronic HCV. Of 103 HCV patients screened for liver fibrosis either with Fibroscan or APRI (aspartate aminotransferase to platelet ratio index), 83 patients (81%) had no indication of severe liver damage. Point of care (POC) HCV tests were used for 46 patients to lower the threshold of attending laboratory testing. All patients preferred POC testing to conventional blood testing. Twenty patients had received HCV treatment, 19 completed the treatment and achieved sustained virologic response (SVR) at the end of the treatment. Of the 18 patients available for evaluation of SVR at 12 weeks after the treatment (SVR12), 17 achieved SVR12. CONCLUSIONS: The integrated model consisting of HCV diagnostics and treatment at the addiction service unit was successfully implemented within normal OAT practice.

Spatial variation in soil carbon in the organic layer of managed boreal forest soil--implications for sampling design.

We studied within-site spatial variation of the carbon stock in the organic layer of boreal forest soil. A total of 1,006 soil samples were taken in ten forest stands (five Scots pine stands and five Norway spruce stands). Our results indicate that the spatial autocorrelation disappears at a distance of 75-225 cm. This spatial autocorrelation should be taken into account in the sampling design by locating the sampling points at adequate intervals. With a sample size of over 20-30 samples per site, additional soil samples do not notably improve the precision of the site mean estimate. An adequate sample size is dependent on the purpose of sampling and on the site-specific soil variation. Our results on the dependence between sample size and precision of the mean estimates can be applied in designing efficient soil monitoring in boreal coniferous forests.

High buprenorphine-related mortality is persistent in Finland.

Sublingual buprenorphine is used in opioid maintenance treatment but buprenorphine is also widely abused and causes fatal poisonings. The aim of this study was to investigate buprenorphine-positive fatalities in order to gain novel information on the magnitude and nature of buprenorphine abuse. All post-mortem toxicology cases positive for urinary buprenorphine, including fatal poisonings caused by buprenorphine and fatalities in which the cause of death was unrelated to buprenorphine, in the five year period of 2010-2014 in Finland were characterized according to urine buprenorphine and naloxone concentrations (n=775). Urine concentrations were used to assess which buprenorphine preparation had been used; mono-buprenorphine or a buprenorphine-naloxone combination, and whether they had been administered parenterally. In at least 28.8% of the buprenorphine-positive cases the drug had been administered parenterally. The majority of the parenteral users (68.6%) had taken mono-buprenorphine. Fatal poisoning was significantly more common among the identified parenteral users (65.5%) than among other users of buprenorphine products (45.3%). The proportion of buprenorphine-related poisoning was similar in identified parenteral users of mono-buprenorphine (68.6%) and buprenorphine-naloxone (64.1%). In nearly all of the fatal poisoningss the deceased had used other drugs and/or alcohol along with buprenorphine (98.7%). The median age of the deceased increased significantly over the study period, from 32 to 38 years. Our results show that there is ongoing parenteral abuse of both mono-buprenorphine and buprenorphine-naloxone combination. Parenteral users of buprenorphine put themselves into a great risk of fatal poisoning or other accidental injury death which is further exacerbated by the frequent poly-drug use.

Prescription opioid abuse based on representative postmortem toxicology.

Opioids are important medications for pain and opioid maintenance treatment. Increasing use and abuse of prescription opioids has, however, caused worldwide concern. Our aim was to estimate the ratio between prescription opioid abuse and total use, based on representative postmortem toxicology. Our material included all the medico-legally examined deaths in Finland during 2010-2011 involving positive findings involving buprenorphine, codeine, fentanyl, methadone, oxycodone, or tramadol. We studied drug abuse by age group, with "abuse" meaning licit opioids used illicitly as narcotics. Drug-abuse history, drug injecting, or laboratory findings of illicit drugs defined an abuser case. We then compared abuser cases and other opioid-related cases between the opioids with the number of fatal poisonings, accidents, suicides, alcohol findings, concomitant opioid use, and median postmortem blood opioid concentrations. Opioid findings numbered 2499 in 2088 cases. Drug abuse involved 545 opioid-positive cases, which in Finland represented 0.5% of those deceased. The proportion of abuser cases among all opioid-related cases for buprenorphine was 85.5%, for methadone 82.4%, for tramadol 29.4%, for codeine 16.3%, for fentanyl 14.5%, and for oxycodone 6.9%. Abuse in age-groups >60 was rare. Concomitant other opioid findings were more frequent in abuser- than in other cases for codeine, oxycodone, and tramadol, whereas alcohol findings were more frequent in buprenorphine, codeine, and fentanyl abuse. Buprenorphine and methadone were most often related to drug abuse. Every other opioid studied involved some abuse, and especially tramadol. Abuse and fatal poisonings were concentrated in men aged 20-49.

Urine naloxone concentration at different phases of buprenorphine maintenance treatment.

In spite of the benefits of buprenorphine-naloxone co-formulation (BNX) in opioid maintenance treatment, the naloxone component has not prevented parenteral use of BNX. Current laboratory methods are not sufficient to differentiate between therapeutic and illicit use of buprenorphine, and little is known about urine naloxone concentrations. Measurement of urine naloxone, together with buprenorphine and norbuprenorphine, might help to determine the naloxone source and administration route. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for this purpose. Naloxone, buprenorphine, and norbuprenorphine total concentrations were measured in urine samples from opioid-dependent patients before and during stable and unstable phases of maintenance treatment with BNX. The limit of quantification in urine was 1.0 µg/L for naloxone, buprenorphine and norbuprenorphine. Before treatment, all samples contained buprenorphine but the median naloxone concentration was 0 µg/L. During the maintenance treatment with BNX all urine samples were positive for naloxone, buprenorphine and norbuprenorphine. The naloxone concentration at a stable phase of treatment (median 60 µg/L, range 5-200 µg/L) was not different from the naloxone concentration at an unstable phase (70 µg/L, 10-1700 µg/L). Applying an upper limit of 200 µg/L to the sample, the median naloxone/buprenorphine ratio was higher in the high than in the low naloxone concentration group (0.9 vs 0.3, respectively). This study suggests that naloxone in urine can act as an indicator of compliance with BNX. Parenteral use of BNX was associated with a high naloxone/buprenorphine ratio. Negative naloxone with positive buprenorphine suggests the use/abuse of buprenorphine alone.

Profiles of pregabalin and gabapentin abuse by postmortem toxicology.

Pregabalin (PRG) and gabapentin (GBP) are used in the treatment of neuropathic pain and epilepsy, and PRG also in generalized anxiety disorder. There is increasing evidence that PRG possesses considerable abuse potential. PRG may have a higher addiction potential than GBP due to its rapid absorption and faster onset of action. Our objective is to estimate the proportion of all PRG- and GBP-related fatalities attributable to PRG and GBP abuse. We investigated all medico-legal death cases in Finland in which PRG or GBP was found in postmortem toxicology during 2010-2011. PRG was found in 316 cases and GBP in 43 cases. Drug abuse was associated with 48.1% of the PRG and 18.6% of the GBP findings. PRG poisoning accounted for 10.1% of all PRG cases and GBP poisoning for 4.7% of all GBP cases. In the drug abuser cases, PRG poisoning represented 19.1%, and GBP poisoning 12.5%. The median blood concentration of PRG was 15 mg/L in the abuser group and 5.8 mg/L in the other cases. For GBP, these concentrations were 12 mg/L and 8.3mg/L, respectively. In the PRG abuser group, 91.4% of cases showed concomitant opioid use, while in the rest of these cases neither alcohol nor opioids were detected, but other central nervous system acting drugs were found in each abuser case. In the GBP abuser group, 87.5% of cases showed concomitant opioid use. PRG abuse with high doses is increasingly common and can be fatal when combined with opioids.

Parenteral buprenorphine-naloxone abuse is a major cause of fatal buprenorphine-related poisoning.

Buprenorphine (BPN) medication for opioid maintenance treatment in Finland consists predominantly of buprenorphine-naloxone (BNX). Both BPN and BNX are associated with diversion, abuse and non-medically supervised use worldwide. Our purpose was to estimate the proportion of BNX to all BPN-related fatalities. The material consisted of 225 deceased drug abusers in Finland from January 2010 to June 2011 with a positive BPN and/or norbuprenorphine (NOR) and/or naloxone (NX) finding in urine. The data were divided into three groups based on the urine NX and BPN concentrations. The "Parenteral BNX" group (>100 µg/l NX) was presumed to consist of injecting or snorting BNX abusers and the "Parenteral BPN" group (>50 µg/l BPN, 0 µg/l NX) of injecting or snorting BPN abusers, while the "Other BNX or BPN" group (≤100 µg/l NX, or ≤50 µg/l BPN combined with 0 µg/l NX) was presumed to consist of mainly sublingual BNX or BPN users. In 12.4% of cases the NX urine concentration was higher than the threshold 100 µg/l. In fatal BPN poisonings, the proportion of parenteral BNX was 28.4%. In the "Parenteral BNX", "Parenteral BPN" and "Other BNX or BPN" groups, the proportion of fatal BPN poisonings was 67.9, 31.0 and 22.6%, respectively. BNX abuse can be fatal. Among the 225 BPN-related fatalities, parenteral abuse of BNX was shown to be common (12.4%) and BNX poisoning was the underlying cause of death in 8.4%. Parenteral BNX caused fatal BPN poisoning proportionally more often than parenteral BPN.

Comparison of fatal poisonings by prescription opioids.

There is a rising trend of fatal poisonings due to medicinal opioids in several countries. The present study evaluates the drug and alcohol findings as well as the cause and manner of death in opioid-related post-mortem cases in Finland from 2000 to 2008. During this period, fatal poisonings by prescription opioids (buprenorphine, codeine, dextropropoxyphene, fentanyl, methadone, oxycodone, tramadol) increased as a share of all drug poisonings from 9.5% to 32.4%, being 22.3% over the whole period. A detailed study including the most prevalent opioids was carried out for the age group of 14-44 years, which is the most susceptible age for drug abuse in Finland. Poisonings by the weak opioids, codeine and tramadol, were found to be associated with large, often suicidal overdoses resulting in high drug concentrations in blood. Methadone poisonings were associated with accidental overdoses with the drug concentration in blood remaining within a therapeutic range. The manner of death was accidental in 43%, 55% and 94% of cases in codeine, tramadol and methadone poisonings, respectively. The median concentration of codeine and the median codeine/morphine concentration ratio were higher in codeine poisonings (1.4 and 22.5 mg/l, respectively) than in other causes of death (0.09 and 5.9 mg/l, respectively). The median concentrations of tramadol and O-desmethyltramadol were higher in tramadol poisonings (5.3 and 0.8 mg/l, respectively) than in other causes of death (0.6 and 0.2 mg/l, respectively). In methadone poisonings, the median concentration of methadone (0.35 mg/l) was not different from that in other causes of death (0.30 mg/l). Sedative drugs and/or alcohol were very frequently found in fatal poisonings involving these prescription opioids.