Methadone-Related Overdose Deaths in a Liberal Opioid Maintenance Treatment Programme.

BACKGROUND/AIMS: Increasing rates of overdose deaths involving opioid maintenance treatment (OMT) medications and particularly methadone have been observed concurrently with the implementation of liberal OMT strategies (i.e. minimum of control and high doses prescribed). This study examined methadone-related overdose deaths in a liberal OMT programme. METHODS: Drug-overdose deaths (n = 130) with detection of methadone in Copenhagen, Aarhus, and Odense Municipality, Denmark, during the period 2008-2011 were identified from a registry. Cases with and without prescribed methadone as OMT were compared. Treatment delivery strategy among OMT-prescribed methadone cases was investigated. RESULTS: Methadone was detected in 130 overdose deaths (71.4% of all overdose deaths). Among these, 63.1% were receiving methadone maintenance treatment. Of these, 79.3% had co-detection of benzodiazepines. Concomitant detection of heroin, non-prescribed benzodiazepines, and younger age were associated with having non-prescribed methadone in the toxicological findings (adjusted OR 3.1, 4.0 and 9.5, respectively). Of the decedents, 43.8% were prescribed a higher methadone dose than recommended (>120 mg daily), of which 80.0% did not have supervised intake of methadone. CONCLUSIONS: Liberal OMT access does not necessarily prevent overdose deaths overall. Prescription of higher doses of methadone combined with benzodiazepines may result in an increased risk of overdose for individuals in as well as outside OMT.

Quantification of morphine, morphine 6-glucuronide, buprenorphine, and the enantiomers of methadone by enantioselective mass spectrometric chromatography in whole blood.

PURPOSE: Deaths among drug addicts are frequently caused by intoxication with methadone and/or morphine. These drugs are often used in combination with other drugs, such as buprenorphine. In addition, methadone is generally used as a mixture of R- and S-enantiomers. To date, a method for separation and quantitation of these specific drugs has not been developed. The aim of this study was to develop a sensitive enantioselective method for quantitation of morphine, its active metabolite morphine 6-glucuronide, buprenorphine, and R- and S-methadone, in a single analytical run. METHODS: Whole blood samples were diluted with 0.5 mol/L ammonium carbonate buffer and extracted on a Bond Elut C18 solid-phase extraction column with an automatic solid-phase extraction system. Chromatographic separation was performed on a chiral alpha-1-acid glycoprotein column with an acetonitrile/ammonium acetate buffer (10 mmol/L, pH 7.0, 22:78 v/v) mobile phase. The whole blood concentrations of the drugs were quantified by mass spectrometry using their stable isotope-labeled compounds as internal standards. RESULTS: The method was validated with respect to specificity, linearity, precision, limits of detection, and quantification and matrix effects. The precision (coefficient of variation) was below 15%, and the accuracy was between 90 and 115%. CONCLUSIONS: This method will be useful for routine analyses in forensic laboratories where blood samples are frequently analyzed for drugs of abuse. In some cases, sudden death from methadone overdose is caused by the enantiomeric form of the methadone, which makes the enantiomer separation capability of this method important.

Fatal poisoning among drug users in Denmark in 2017.

INTRODUCTION: Knowledge of trends of illegal drug use is vital for planning initiatives to reduce accidents and deaths among drug users. The aim of this study was to describe the cause of death, abuse pattern and geographic differences in fatal poisonings among drug users in Denmark in 2017. METHODS: All fatal poisonings among drug users examined at the three institutes of forensic medicine in Denmark in 2017 were included in the study. RESULTS: Overall, fatal poisonings declined from a maximum of 226 in 2007 to 162 in 2017. Methadone (52%) was the most common cause of death, followed by heroin/morphine (25%). A marked increase in deaths was due to stimulants (13%), especially cocaine. The abuse pattern has changed since 2012. Methadone remained the most frequently detected drug, but clonazepam and cocaine surpassed heroin/morphine, diazepam and tetrahydrocannabinol as the second-most frequently detected drugs. Ketobemidone had disappeared, whereas buprenorphine, oxycodone, fentanyl, pregabalin and gabapentin had increased. Antidepressants/antipsychotics were detected in half (47%) of the cases. Cocaine was more frequent in the areas covered by Copenhagen and Aarhus, whereas heroin/morphine was most frequently detected in the area covered by Odense. Amphetamine was more frequent in the Aarhus area. CONCLUSIONS: Methadone and heroin/morphine still account for most fatal poisonings. However, deaths due to stimulants, especially cocaine, have increased. The abuse pattern has changed and geographical differences have emerged. FUNDING: none. TRIAL REGISTRATION: not relevant.

The ABCB1, rs9282564, AG and TT Genotypes and the COMT, rs4680, AA Genotype are Less Frequent in Deceased Patients with Opioid Addiction than in Living Patients with Opioid Addiction.

Sudden death due to acute intoxication occurs frequently in patients with opioid addiction (OA). To examine whether certain genotypes were associated with this, we examined the frequencies of 29 SNPs located in candidate genes related to opioid pharmacology: ABCB1, OPRM1, UGT2B7, CYP3A5, CYP2B6, CYP2C19, CYP2D6, COMT, KCNJ6 and SCN9A in 274 deceased patients with OA (DOA), 309 living patients with OA (LOA) and in 394 healthy volunteers (HV). The main hypothesis of the study was that subjects homozygous for the variant 3435T in ABCB1 (rs1045642) occur more frequently in DOA than in LOA and HV because morphine and methadone more readily cross the blood barrier in these subjects due to a lower efflux transporter activity of the ABCB1 (p-glycoprotein) transporter. Our results did not support this hypothesis, because no statistically significant difference (p = 0.506) in the frequency of the TT genotype of rs1045642 was observed between the DOA, LOA and HV cohorts. However, for another ABCB1 variant, rs9282564, we found that the frequencies of the AG and TT genotypes were 13, 21 and 25% in DOA, LOA and HV, respectively, and after correcting for age, sex and multiple testing, the differences between DOA and LOA were statistically significantly different (p = 0.027). The COMT rs4680 AA genotype frequencies were 25%, 35% and 31% in DOA, LOA and HV, respectively, and the difference between DOA and LOA was also statistically significant (p = 0.0028). In conclusion, this study generated two hypotheses suggesting possible associations of a reduced risk of death and carrying, respectively, the ABCB1 rs9282564 AG and TT genotypes and the COMT rs4680 AA genotype among patients with OA. These findings should be confirmed in independent cohorts, and if a causal relationship between these variants and fatal poisoning in OA is confirmed, then it may be possible at least in theory to personalize prevention of sudden death in this patient group.

Fatal poisoning among patients with drug addiction.

INTRODUCTION: Fatal poisonings among drug addicts in Denmark in 2012 were examined. Cause of death, abuse pattern and geographic differences are discussed and data are compared with previous studies. METHODS: All fatal poisonings examined at the three institutes of forensic medicine in Denmark in 2012 were included in the study. RESULTS: A total of 188 fatal intoxications were recorded. The median age increased from 37.5 in 2007 to 41.5 in 2012. The majority were men (77%). Methadone (59%) was the main intoxicant. The decrease in the frequency of heroin/morphine deaths since 1997 (71%) continued, declining to 44% in 2002, 33% in 2007 and finally to 27% in 2012. Few deaths from central stimulants (amphetamine and cocaine) occurred. Multiple drug use was common and consisted mainly of opioids, cocaine, amphetamine, cannabis, benzodiazepines and alcohol. Heroin/morphine use was most frequent on Funen and in South Jutland. Cocaine was most frequently detected in East Denmark, while amphetamine was more frequent in West Denmark. CONCLUSIONS: The number of fatal poisonings among drug addicts has stabilised around 200. The increase in methadone deaths continued and, as in 2007, methadone was the main intoxicant. The increase in methadone deaths seems to be associated with use of methadone in substitution treatment. Nevertheless, methadone treatment also seems to save lives, as indicated by the increasing median age. Use of antidepressants and antipsychotics increased to a high level compared with 2007, indicating that a considerable number of drug addicts also have psychiatric illness. FUNDING: none. TRIAL REGISTRATION: not relevant.