Epidemiology of alcohol-related unintentional drowning: is post-mortem ethanol production a real challenge?

BACKGROUND

Post-mortem (PM) ethanol production may hamper the interpretation of blood alcohol concentration (BAC) in victims of drowning. Different exclusion criteria (e.g. cases with low BAC or with protracted interval between death and toxicological analysis) have been proposed with no factual figures to reduce the potential bias due to PM ethanol production when examining the prevalence rates for alcohol-related drowning. The aim of this study is to verify the extent to which PM alcohol production may affect the accuracy of studies on drowning and alcohol.

FINDINGS

Unintentional fatal drowning cases (n = 967) for which a full medico-legal autopsy and toxicological analysis was performed, in Finland, from 2000 to 2013, and relevant variables (demographic data of the victims, month of incident, PM submersion time, blood alcohol concentration, urine alcohol concentration (UAC), vitreous humour alcohol concentration (VAC) were available. Overall, out of 967 unintentional drownings, 623 (64.4%) were positive for alcohol (BAC > 0 mg/dL), 595 (61.5%) had a BAC ≥ 50 mg/dL, and 567 (58.6%) a BAC ≥ 100 mg/dL. Simultaneous measurements, in each victim, of BAC, UAC, and VAC revealed PM ethanol production in only 4 victims (BAC: 25 mg/dL - 48 mg/dL). These false positive cases represented 0.4% of drownings with BAC > 0 mg/dL and 14.3% of drownings with BAC > 0 mg/dL and < 50 mg/dL.

CONCLUSIONS

The present study suggests that PM ethanol production has a limited impact on research addressing the prevalence rate for alcohol-related drowning and that the use of too rigorous exclusion criteria, such as those previously recommended, may led to a significant underestimation of actual alcohol-positive drowning cases.

Purchases of prescription drugs before an alcohol-related death: A ten-year follow-up study using linked routine data

BACKGROUND

Physician's intention to prescribe drugs could potentially be used to improve targeting of alcohol interventions and enhanced disease management to patients with a high risk of severe alcohol-related harm within outpatient settings.

METHODS

Comparison of ten-year incidence trajectories of 13.8 million reimbursed purchases of prescription drugs among 303,057 Finnish men and women of whom 7490 ultimately died due to alcohol-related causes (Alc+), 14,954 died without alcohol involvement (Alc-), and 280,613 survived until the end of 2007.

RESULTS

5-10 years before death, 88% of the persons with an Alc+ death had received prescription medication, and over two-thirds (69%) had at least one reimbursed purchase of drugs for the alimentary tract and metabolism, the cardiovascular system, or the nervous system. Among persons with an Alc+ death, the incidence rate (IR) for purchases of hypnotics, and sedatives was 1.38 times higher (95% confidence interval (CI):1.32,1.44) compared to those with an Alc- death, and 4.07 times higher (95%CI:3.92,4.22) compared to survivors; and the IR for purchases of anxiolytics was 1.40 times higher (95%CI:1.34,1.47) compared to those with an Alc- death, and 3.61 times higher (95%CI:3.48,3.78) compared to survivors.

CONCLUSIONS

Using physician's intention to prescribe drugs affecting the alimentary tract and metabolism, cardiovascular system and nervous system could potentially be used to flag patients who might benefit from screening, targeted interventions or enhanced disease management. In particular, patients who are to be prescribed anxiolytics, hypnotics, and sedatives, and antidepressants may benefit from enhanced interventions targeted to problem drinking.

Unintentional drowning: Role of medicinal drugs and alcohol

BACKGROUND

Alcohol is a well-known risk factor in unintentional drownings. Whereas psychotropic drugs, like alcohol, may cause psychomotor impairment and affect cognition, no detailed studies have focused on their association with drowning. Finland provides extensive post-mortem toxicological data for studies on drowning because of its high medico-legal autopsy rates.

METHODS

Drowning cases, 2000 through 2009, for which post-mortem toxicological analysis was performed, came from the database of the Toxicological Laboratory, Department of Forensic Medicine, University of Helsinki, using the ICD-10 nature-of-injury code T75.1. The data were narrowed to unintentional drowning, using the ICD-10 external-injury codes V90, V92, and W65-74. Each drowning case had its blood alcohol concentration (BAC) and concentrations of other drugs recorded. Evaluation of the contribution of psychotropic drugs to drowning was based on their blood concentration by means of a 6-grade scale.

RESULTS

Among victims ≥15 years old, unintentional drownings numbered 1697, of which, 303 (17.9%) were boating-related and 1394 (82.1%) non-boating-related. Among these, 65.0% of boating-related and 61.8% of non-boating-related victims were alcohol-positive (=BAC ≥ 50 mg/dL). The male-to-female ratio in alcohol-positive drownings was 7.3. At least one psychotropic drug appeared in 453 (26.7%) drowning cases, with some victims' bodies showing up to 7 different drugs. Overall 70 different psychotropic drugs were detectable, with 134 (7.9%) cases both alcohol-negative and psychotropic-drug-positive, of these, 59 (3.5%) were graded 4 to 6, indicating a possible to very probable contribution to drowning. Our findings suggest that psychotropic drugs may play a significant role in drowning, in up to 14.5% of cases, independently or in association with alcohol.

CONCLUSIONS

Psychotropic drugs alone or in association with alcohol may be an overlooked risk factor in drowning, due to their effects on psychomotor function and cognition. Future studies should also address other mechanisms-for instance drug-induced long-QT syndrome-by which drugs may contribute to drowning.

Fatal toxicity index of medicinal drugs based on a comprehensive toxicology database

The fatal toxicity index (FTI) is the absolute number of fatal poisonings caused by a particular drug divided by its consumption figure. Consequently, it is a useful measure in evaluating toxicity of the drug and its relevance in fatal poisonings. In this study, we assessed the FTI of medicinal drugs in 3 years (2005, 2009, and 2013) in Finland. As the measure of drug consumption, we used the number of defined daily doses (DDD) per population in each year. There were 70 medicinal drugs in Finland for which the mean FTI expressed as the number of deaths per million DDD over the three study years was higher or equal to 0.1. The Anatomical Therapeutic Chemical (ATC) classification system was used for the classification of the active ingredients of medicinal drugs according to the organ or system which they act on. Of these 70 drugs, 55 drugs (78.6 %) acted on the nervous system (denoted by ATC code N), 11 (15.7 %) on the cardiovascular system (C), three (4.3 %) on the alimentary tract and metabolism (A), and one (1.4 %) on the musculoskeletal system (M). The nervous system drugs consisted of 20 psycholeptics, (ATC code N05), 20 psychoanaleptics (N06), eight analgesics (N02), six antiepileptics (N03), and one other nervous system drug (N07). The highest individual FTIs were associated with the opioids methadone, dextropropoxyphene, oxycodone, tramadol, and morphine; the antipsychotics levomepromazine and chlorprothixene; and the antidepressants doxepin, amitriptyline, trimipramine, and bupropion. Buprenorphine was not included in the study, because most of the fatal buprenorphine poisonings were due to smuggled tablets. A clearly increasing trend in FTI was observed with pregabalin and possibly with bupropion, both drugs emerging as abused substances.

Cause and manner of death and phase of the blood alcohol curve

In a large number of forensic autopsies (N = 28,184) the concentrations of ethanol in femoral blood and bladder urine were determined and the urine-to-blood concentration ratios of ethanol were calculated. Based on the differences in ethanol concentration between urine and blood, the deaths were classified as having occurred during the absorptive, the peak or the post-absorptive phase of the blood–alcohol curve. Most people died in the post-absorptive phase, N = 24,223 (86%), whereas 1538 individuals (5.5%) were still absorbing alcohol and 2423 (8.6%) were at or close to the peak BAC at time of death. Both blood–alcohol concentration (BAC) and urine–alcohol concentration (UAC) were significantly higher in the post-absorptive phase (p < 0.001). The proportions of people dying in the absorptive and peak phases increased with advancing age. The cause of death (CoD) and manner of death (MoD) according to death certificates were compared with phase of the blood–alcohol curve using a multinomial regression model with and without making adjustment for possible effects of age, gender and BAC. The relative risk (RR) and relative risk ratios (RRR) showed some associations between CoD and phase of the blood–alcohol curve. Undetermined MoD was significantly higher in the absorptive phase compared with the post-absorptive phase (RRR = 2.12). Deaths related to esophagus, stomach and duodenum (RRR = 2.04) and alcoholic liver diseases (RRR = 1.85) were significantly higher at or close to peak phase compared to the post-absorptive phase. Road-traffic fatalities were more prevalent in the peak BAC phase (RRR = 1.33) and deaths by accidental falls were less in the absorptive phase (RRR = 0.58) compared with the post-absorptive phase. The phase of alcohol intoxication seems relevant to consider by forensic experts when alcohol-related deaths are investigated.

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.

Personally prescribed psychoactive drugs in overdose deaths among drug abusers: a retrospective register study

INTRODUCTION AND AIMS

Psychoactive prescription drug (PPD) abuse-related overdose deaths have increased in many countries in recent decades. We aimed to investigate the role of personally prescribed psychoactive drugs in abuse-related overdose mortality and explore any associations with level of social disadvantage.

DESIGN AND METHODS

This register linkage study included all 243 people who had died of abuse-related drug-induced poisoning in Finland in 2000 and 2008. Data on registered purchases of psychoactive drugs within one and three years of death were linked to data on the psychoactive drug/s contributing to death in each case. Social disadvantage was measured by receipt of income support, long-term unemployment and disability pension.

RESULTS

Thirty-six percent of those abusers who had died of a drug overdose had purchased a similarly acting drug within three years of death. In all overdoses, the proportion increased from 20% in 2000 to 49% in 2008 (P < 0.001). A similar increase was seen in purchases within one year of death; from one-tenth in 2000 to one-third of all cases in 2008 (P < 0.001). The majority (83%) of the deceased had received income support, while only 13-14% were long-term unemployed or on disability pension. Disability pension recipients had significantly more prescribed psychoactive drug purchases than non-recipients (P < 0.001 for three and one years within death).

DISCUSSION AND CONCLUSIONS

Personally prescribed PPDs pose a potential threat to people who abuse drugs. Health-care services should invest greater effort in identifying people who abuse drugs and in monitoring their drug prescriptions.

Wastewater analysis reveals regional variability in exposure to abused drugs and opioids in Finland

Abused drug concentrations were determined in nine Finnish wastewater treatment plants (WWTPs), representing the metropolitan area, university cities and rural towns. In an eight-day study period in August 2012, 24-hour composite influent wastewater samples were collected. Biological markers and census-based information were used to estimate the size of the population served. The analytical method included solid phase extraction, liquid chromatographic separation, tandem mass spectrometric identification, and quantification using isotope-labeled internal standards. The study covered amphetamines, cannabis and cocaine. The levels of some opioids used in treatment and their metabolites were also determined. Amphetamine was the most prevalent drug of abuse, the median loads varying between the cities from 4.16 to 29.6 mg/1000 inhabitants/d. In three western cities methamphetamine was detected in even higher amounts, ranging from 0.87 to 47.5mg/1000 inhabitants/d. Ecstasy (MDMA) and cocaine (as benzoylecgonine, BE) were found in higher concentrations during weekends compared to weekdays, the difference being statistically significant. The concentration of tetrahydrocannabinol-9-carboxylic acid (THCA) was below the limit of quantification in the two rural towns, while in the other cities the load varied between 3.77 and 20.7 mg/1000 inhabitants/d. The average variation in BE load was 0.05-6.82 and that of MDMA 0-20.6 mg/1000 inhabitants/d. While the metropolitan area showed the highest loads of abused drugs, the substances were continuously detected at all WWTPs included in the study. The median concentration of codeine ranged from 164 to 325 mg/1000 inhabitants/d and that of morphine from 18.8 to 31.5mg/1000 inhabitants/d. The methadone load was below the level of detection in two towns, and at the other locations were 1.22-9.46 mg/1000 inhabitants/d. The first metabolite of heroin, 6-monoacetylmorphine (6-MAM), was not detected at all. Although the method has limitations, wastewater analysis gives additional information for assessing the degree of drug abuse and range of drugs abused in a society.

Second-generation antihistamines exhibit a protective effect on drivers in traffic-a preliminary population-based case-control study

INTRODUCTION

Although there have been experimental studies concerning driving and drugs, studies on the risk of antihistamines are not numerous. This is the first population-based epidemiological study concerning the association of sedating/nonsedating antihistamines and fatal traffic accidents.

METHODS

Car drivers (n = 428) who died in accidents before reaching the hospital and controls (n = 688) matched for accident area and driving season were studied for antihistamines in blood. At the time of the fatal road traffic accident, 6 drivers had a detectable amount of sedating antihistamines in blood, and the corresponding number for controls was 4; nonsedating antihistamines in blood were detected in 12 accident cases and 28 controls. The fatal accidents occurred between 1998 and 2002 and the information on the controls was collected between 2000 and 2002 in Finland.

RESULTS

Regarding fatal traffic accident causality, the nonsedating antihistamines proved to have a protective effect after adjusting for age and gender (relative risk = 0.40, 95% confidence interval [CI], 0.20 to 0.82; P =.01). The risk of fatal traffic accident of those driving under the influence of sedating antihistamines was 1.61 (0.38 to 6.77, P =.51) times the risk of those without medication.

DISCUSSION

This preliminary study supports the protective effect of second-generation antihistamines with respect to fatal traffic accidents. Due to the small sample size the results are not conclusive.

Fatal poisonings in Finland during the years 2004-2009

Fatal alcohol and drug poisonings in Finland during the years 2004-2009 were studied. Cases were divided into those that occurred outside the hospitals (the majority of cases) and those that occurred within the hospitals (the minority of cases). Differences and similarities between the two groups were analysed. The postmortem toxicological investigation of all sudden and unexpected deaths in Finland is centralised at the Department of Forensic Medicine, University of Helsinki. We examined each fatal poisoning separately and verified the cause and place of death as well as the age and sex of the deceased. Fatal poisonings, including suicides, have remained unchanged for many years from the same high level, that is, about 1200 cases annually (22/100,000 inhabitants). The number of patients dying in hospitals due to poisoning has also remained stable (55-70 patients/year). However, the toxic agents involved in such poisonings have changed and deaths due to opioids are now being more numerous. The number of fatal unintentional drug poisonings rose significantly from 191 to 341 (3-6/100,000 inhabitants, p < 0.001) during the study years, and the difference between poisonings caused by drugs or alcohol also changed significantly (p < 0.001). Diminishing substantially, the number of all fatal poisonings will be challenging because of the high percentage of suicides. However, a reduction in unintentional drug overdoses, which are presently on the rise, should be possible.

Drugs related to motor vehicle crashes in northern European countries: a study of fatally injured drivers

The aim of this study was to find which drugs and drug combinations were most common in drivers who died, in particular, in single vehicle crashes where the responsibility for the crash would be referred to the driver killed. The study included all available blood samples from drivers, who died within 24h of the accident, in the years 2001 and 2002 in the five Nordic countries (total population about 24 million inhabitants). The samples were analysed for more than 200 different drugs in addition to alcohol, using a similar analytical programme and cut-off limits in all countries. In three countries (Finland, Norway and Sweden) blood samples were available for more than 70% of the drivers, allowing representative prevalence data to be collected. 60% of the drivers in single vehicle crashes had alcohol and/or drug in their blood samples, compared with 30% of drivers killed in collisions with other vehicles. In single vehicle accidents, 66% of the drivers under 30 years of age had alcohol and/or drugs in their blood (alcohol only - 40%; drugs only - 12%; alcohol and drugs - 14%). The drugs found were mostly illicit drugs and psychoactive medicinal drugs with warning labels (in 57% and 58% respectively of the drivers under 30 with drugs present). Similar findings were obtained for drivers 30-49 years of age (63% with alcohol and/or drugs). In drivers aged 50 years and above, killed in single vehicle crashes (48% with alcohol and/or drugs) illicit drugs were found in only one case, and psychoactive medicinal drugs were detected less frequently than in younger age groups. In 75% of single vehicle crashes, the driver was under 50 years. Thus, the majority of accidents where the drivers must be considered responsible, occurred with drivers who had recently used alcohol, or drugs, alone or in combination. The drugs involved were often illicit and/or psychoactive drugs with warning labels. Therefore a large proportion of single vehicle accidents appear to be preventable, if more effective measures against driving after intake of alcohol and drugs can be implemented.

Under-recording of ethanol intoxication and poisoning in cause-of-death data: causes and consequences

In the present study we examined how consistently and completely the role of acute alcohol (ethanol) intake as a cause of death is reported on death certificates, how complete and specific the statistical recording of cause-of-death data on acute alcohol-induced deaths is, and how the information ultimately appears in the national mortality statistics. Data on all alcohol-positive deaths with blood alcohol concentration of ≥ 0.5‰ (g/kg) in Finland in 2005 (N = 2348) were reviewed. Overall, a concentration-dependent association was found between forensic-toxicologically determined blood alcohol concentrations and acute alcohol-specific cause-of-death diagnoses. Based on a medico-legal re-evaluation of death certificates, acute alcohol-specific causes were found to be underreported nationally at a rate of 8%. For accidental alcohol poisonings alone, the figure was about 1%. This underreporting was not corrected during recording of the cause-of-death data, though individual corrections and changes were observed. Especially, recording of multiple causes suffers from this underreporting of acute alcohol-specific causes. ICD-10 seems to do well in fulfilling the demands for a specific classification of uncomplicated alcohol poisoning. In combined alcohol-drug poisonings, however, ICD-10 shows a bias towards drugs over alcohol, even when alcohol has been specified and reported as the most toxic component by the medico-legal pathologist. Since the national statistics is based on the underlying causes, this state of affairs is likely to result in the underestimation of the role of acute alcohol intake as a cause of death. This observation of underreporting of acute alcohol-specific causes on death certificates should result in a harmonisation of education and principles and practices used in death certification. To increase the coverage and specificity of mortality statistics, based on the underlying causes of death, the coding of all components of alcohol-drug combinations and their classification according to the most important intoxicant or combination of intoxicants is recommended.

Elevated formic acid concentrations in putrefied post-mortem blood and urine samples

Formic acid (FA) concentration was measured in post-mortem blood and urine samples as methyl formate using a headspace in-tube extraction gas-chromatography-mass-spectrometry method. A total of 113 cases were analyzed, each including a blood and urine sample fortified with 1% sodium fluoride. The cases were divided into three groups: regular (n=59), putrefied (n=30), and methanol-positive (n=22) cases. There was no evidence of ante-mortem methanol consumption in the regular and putrefied cases. In regular cases, the mean (and median) FA concentrations were 0.04 g/l (0.04 g/l) and 0.06 g/l (0.04 g/l) in blood and urine, respectively. In putrefied cases, the mean (and median) FA concentrations were substantially higher, 0.24 g/l (0.22 g/l) and 0.25 g/l (0.15 g/l) in blood and urine, respectively. In three putrefied cases, FA concentration in blood exceeded 0.5 g/l, a level associated with fatal methanol poisoning. Ten putrefied cases were reanalyzed after 3-4 months storage, and no significant changes in FA concentrations were seen. These observations suggest that FA was formed by putrefaction during the post-mortem period, not during sample storage when sodium fluoride was added as a preservative. In methanol-positive cases, the mean (and median) FA concentrations were 0.80 g/l (0.88 g/l) and 3.4 g/l (3.3 g/l) in blood and urine, respectively, and the concentrations ranged from 0.19 to 1.0 g/l in blood and from 1.7 to 5.6 g/l in urine. The mean (and median) methanol concentrations in methanol-positive cases were 3.0 g/l (3.0 g/l) and 4.4 g/l (4.7 g/l) in blood and in urine, respectively. The highest methanol concentrations were 6.0 g/l and 8.7 g/l in blood and urine, respectively. No ethyl alcohol was found in the methanol-positive blood samples. Poor correlation was shown between blood and urine concentrations of FA. Poor correlations were also shown, in both blood and urine, between methanol and FA concentrations.

Headspace in-tube extraction gas chromatography-mass spectrometry for the analysis of hydroxylic methyl-derivatized and volatile organic compounds in blood and urine

A novel headspace in-tube extraction gas chromatography-mass spectrometry (ITEX-GC-MS) approach was developed for broad-scale analysis of low molecular weight organic compounds in blood and/or urine. One sample was analyzed following in-vial derivatization with dimethyl sulfate for ethylene glycol (EG), glycolic acid (GA), formic acid (FA), other hydroxylic compounds, and another sample for underivatized volatile organic compounds. Tenax adsorbent resin was used in the microtrap, and a porous layer, open tubular GC capillary column was used for separation. MS was operated in the full-scan mode, identification was based on the Automated Mass Spectral Deconvolution and Identification System, and quantification was based on extracted ions. The limits of quantification for EG, GA, and FA in blood were 10, 50, and 30 mg/L, respectively, and the expanded uncertainties of measurement were 20%, 16%, and 14%, respectively. The procedure allowed for the first time the inclusion of EG and GA as their methyl derivatives within a quantitative HS analysis. The ITEX method described here was more sensitive for analysis of volatile organic compounds than the corresponding static headspace analysis as demonstrated for 11 representative compounds.

Fatal venlafaxine poisonings are associated with a high prevalence of drug interactions

Venlafaxine (VEN) is an antidepressant found to possess a higher fatal toxicity index (FTI, i.e., deaths in proportion to consumption) than other newer antidepressants and selective serotonin reuptake inhibitors (SSRIs). The aim of this study was to elucidate using post-mortem cases whether the apparent high toxicity of VEN is associated with adverse drug interactions, pharmacogenetic factors and/or the manner of death. Within a 2-year period, a comprehensive post-mortem database and death certificates were searched for cases with laboratory findings of VEN, findings of other drugs, associated background information and the cause and manner of death. In 123 cases, the concentrations of VEN and its two metabolites, O-desmethylvenlafaxine (O-VEN) and N-desmethylvenlafaxine (N-VEN), and the CYP2D6 genotype were determined in post-mortem blood. The median concentrations of VEN, O-VEN and N-VEN were 560, 420 and 49 µg/l, respectively. A prominent feature of the VEN-positive cases was the high abundance of interacting drugs (46%), being more common with higher VEN concentrations. Compared to other common antidepressants, VEN-positive cases showed the highest suicide frequency, but also the proportion of suicidal VEN poisonings of all suicides was substantially higher than that of mirtazapine or SSRIs. Relative CYP2D6 activity did not predispose to high VEN concentrations, and the frequency of the extreme phenotypes followed the general population. In conclusion, the high suicide potential of VEN in combination with the high prevalence of drugs causing adverse interactions could be the reason for the observed high FTI.

Prevalence of hemochromatosis in Finland

Transferrin saturation was determined in 11,431 men and 10,639 women aged 15 or more drawn from different areas in southern and central Finland and attending a multiphasic health screening examination in 1967-1972. All the 163 men and 66 women with transferrin saturation greater than or equal to 70% at the initial examination and still alive at the end of 1983 were invited to a re-examination. Of the invited persons, 76% attended the re-examination. Transferrin saturation and serum ferritin were the initial screening methods in the re-examination. All persons with suspected hemochromatosis were clinically examined and a laparoscopy was performed. Four men and four women were found with unequivocal hemochromatosis. Only one of these cases was diagnosed beforehand. According to these data the prevalence of hemochromatosis in Finland is about 50/100,000.

Prevalence of adverse drug combinations in a large post-mortem toxicology database

The prevalence of important adverse drug combinations was studied among the 37,367 cases included in the Finnish post-mortem toxicology database during 2000-2006. The new SFINX interaction database (Swedish, Finnish, INteraction X-referencing) was utilised to identify adverse drug combinations. Consequently, the 24 drugs chosen for the study generated 96 two-compound combinations possessing potentially severe interactions. The total number of hits for the combinations found in the post-mortem database was 267, which accounts for approximately 0.71% of all cases. The potential role of adverse drug interaction (ADI) in these cases was evaluated from the background information and death certificate. The possible ADI cases comprised 23% of all hits and 0.17% of all cases analysed. In cases with a pharmacodynamic mechanism, the most prominent combinations were medicines causing serotonin syndrome or a beta(1)-blocker with verapamil or diltiazem. In cases with a pharmacokinetic mechanism, half of the cases involved digoxin in combination with verapamil. In one third of the possible ADI cases, a forensic pathologist had noted the studied compounds as an underlying or contributing cause of death, although the agents' specific role in ADIs was rarely recognised.

A Fatal Doxepin Poisoning Associated With a Defective CYP2D6 Genotype

It has been suggested that the polymorphism of the CYP2D6 gene can contribute to occurrence of fatal adverse effects. We therefore investigated postmortem toxicology cases of fatal drug poisonings related to CYP2D6 substrates, with the manner of death denoted as accidental or undetermined. CYP2D6 genotypes were determined in 11 consecutive cases with samples available for DNA analysis. A case of fatal doxepin poisoning with an undetermined manner of death was found to coincide with a completely nonfunctional CYP2D6 genotype (*3/*4), indicating a total absence of CYP2D6 enzyme and suggesting a poor metabolizer phenotype. The doxepin concentration was 2.4 mg/L, the concentration of nordoxepin 2.9 mg/L, and the doxepin/nordoxepin ratio 0.83, the lowest found among the 35 nordoxepin-positive postmortem cases analyzed during the same year. No alcohols or other drugs were detected in the case. The CYP2C19 genotype was determined as that of an extensive metabolizer. The high N-desmethylmetabolite concentration is not consistent with acute intoxication. It is therefore probable that the defective genotype has contributed to the death, possibly involving repeated high dosage of doxepin. Our case strongly emphasizes that a pharmacogenetic analysis in postmortem forensic setting may reveal new insight to the cause or manner of death.

Quantification of Drugs in Plasma Without Primary Reference Standards by Liquid Chromatography-Chemiluminescence Nitrogen Detection: Application to Tramadol Metabolite Ratios

Lack of availability of reference standards for drug metabolites, newly released drugs, and illicit drugs hinders the analysis of these substances in biologic samples. To counter this problem, an approach is presented here for quantitative drug analysis in plasma without primary reference standards by liquid chromatography-chemiluminescence nitrogen detection (LC-CLND). To demonstrate the feasibility of the method, metabolic ratios of the opioid drug tramadol were determined in the setting of a pharmacogenetic study. Four volunteers were given a single 100-mg oral dose of tramadol, and a blood sample was collected from each subject 1 hour later. Tramadol, O-desmethyltramadol, and nortramadol were determined in plasma by LC-CLND without reference standards and by a gas chromatography-mass spectrometry reference method. In contrast to previous CLND studies lacking an extraction step, a liquid-liquid extraction system was created for 5-mL plasma samples using n-butyl chloride-isopropyl alcohol (98 + 2) at pH 10. Extraction recovery estimation was based on model compounds chosen according to their similar physicochemical characteristics (retention time, pKa, logD). Instrument calibration was performed with a single secondary standard (caffeine) using the equimolar response of the detector to nitrogen. The mean differences between the results of the LC-CLND and gas chromatography-mass spectrometry methods for tramadol, O-desmethyltramadol, and nortramadol were 8%, 32%, and 19%, respectively. The sensitivity of LC-CLND was sufficient for therapeutic concentrations of tramadol and metabolites. A good correlation was obtained between genotype, expressed by the number of functional genes, and the plasma metabolite ratios. This experiment suggests that a recovery-corrected LC-CLND analysis produces sufficiently accurate results to be useful in a clinical context, particularly in instances in which reference standards are not readily accessible.

Abuse liability of buprenorphine-naloxone tablets in untreated IV drug users

Buprenorphine (Subutex) is widely abused in Finland. A combination of buprenorphine plus naloxone (Suboxone) has been available since late 2004, permitting a comparison of the abuse of the two products among untreated intravenous (IV) users. A survey was distributed to attendees at a Helsinki needle exchange program over 2-weeks in April, 2005, At least 30% were returned anonymously. Survey variables included: years of prior IV opioid abuse, years of buprenorphine abuse, frequency, dosage, route of administration and reasons for use, concomitant IV abuse of other substances and amount paid on the street for both buprenorphine and buprenorphine+naloxone. Buprenorphine was the most frequently used IV drug for 73% of the respondents. More than 75% said they used IV buprenorphine to self-treat addiction or withdrawal. Most (68%) had tried the buprenorphine+naloxone combination IV, but 80% said they had a "bad" experience. Its street price was less than half that of buprenorphine alone. The buprenorphine+naloxone combination appears to be a feasible tool, along with easier access to addiction treatment, for decreasing IV abuse of buprenorphine.

Alcohol tax cuts and increase in alcohol-positive sudden deaths: a time-series intervention analysis

AIMS

The impact of alcohol regulation changes in Finland during 2004 on alcohol-positive sudden deaths was analysed, focusing on: (1) removal of traveller's allowance quotas on alcohol imports from other European Union (EU) countries, (2) lowering of Finnish alcohol excise duty rates and (3) Estonia joining the EU.

DESIGN

The impact of these changes was estimated using an autoregressive integrated moving average (ARIMA) analytical technique. Post-mortem forensic toxicology data were analysed over a 15-year period to account for seasonal and long-term variation. In all, the data comprised a weekly series of 33,782 alcohol-positive cases (at least 0.20 mg/g alcohol in blood) and a control series of 37,617 alcohol-negative cases.

SETTING

Finland in 1990-2004.

FINDINGS

The liberation of traveller's allowances had no material impact on alcohol-positive sudden deaths, but the impact of alcohol tax cuts in March 2004 was significant, resulting in an estimated eight additional alcohol-positive deaths per week, which is a 17% increase compared with the weekly average of 2003. The impact associated with Estonia joining the EU was not statistically significant. In the models applied to the control series of alcohol-negative deaths, none of the impact coefficients was statistically significant.

CONCLUSIONS

Alcohol tax cuts were associated with an increase in the number of sudden deaths involving alcohol. This parallels the reported increases in alcohol consumption and alcohol-related causes of death in 2004 in Finland.

Blood levels of 3-methylfentanyl in 3 fatal poisoning cases

Three fatal poisoning cases due to 3-methylfentanyl are described. In each case, the death was accidental and occurred after injection of the opioid combined with amphetamine, heroin, or other drugs. The victims' ages, ranging from 30 to 41 years, were higher than those typically found in heroin poisonings in Finland. The blood concentrations of cis-3-methylfentanyl, measured here for the first time by a specific tandem mass spectrometric method, ranged from 0.3 to 0.9 microg/L (mean 0.5 microg/L). These values are significantly lower than the levels reported for alpha-methylfentanyl and fentanyl in fatal poisonings. Repeated seizures of fentanyl and its analogs have been reported in Europe close to the Russian border.

Recurrent opioid toxicity after pre-hospital care of presumed heroin overdose patients

BACKGROUND

In patients with presumed heroin overdose, the recommended time of observation after reversing heroin toxicity with naloxone varies widely. The aims of this study were to examine the incidence of recurrent opioid toxicity and the time interval in which it occurs after pre-hospital treatment in presumed heroin overdose patients.

METHODS

We undertook a retrospective study in Helsinki (population, 560,000). Records were reviewed from 1 January 1995 to 31 December 2000. Patients included were treated by the emergency medical service (EMS) for a presumed heroin overdose. Patients with known polydrug/alcohol use or the use of opioids other than heroin were excluded. The EMS records were compared with the cardiac arrest database and the medical examiners' records.

RESULTS

One hundred and forty-five patients were included. The median dose of pre-hospital administered naloxone was 0.4 mg. After pre-hospital care, 84 patients refused further care and were not transported to an emergency department (ED). Seventy-one received pre-hospital naloxone, and no life-threatening events were recorded during a 12-h follow-up period in these patients. After pre-hospital care, 61 patients were transported to an ED. Twelve patients received naloxone in the ED for respiratory depression. All had signs of heroin use-related adverse events within 1 h after receiving pre-hospital naloxone.

CONCLUSIONS

Allowing presumed heroin overdose patients to sign out after pre-hospital care with naloxone is safe. If transported to an ED, a 1-h observation period after naloxone administration seems to be adequate for recurrent heroin toxicity.

Outcome after heroin overdose and cardiopulmonary resuscitation

BACKGROUND

The survival of heroin overdose patients resuscitated from cardiac arrest is reported to be poor. The aim of our study was to investigate the outcome and characteristics of survivors after cardiac arrest caused by heroin overdose.

METHODS

This was a retrospective study in a medium-sized city (population, 560,000). Between 1 January 1997 and 31 December 2000, there were 94 combined cardiac arrests caused by acute drug poisonings. The main outcome measure was survival to discharge.

RESULTS

Cardiopulmonary resuscitation was attempted in 19 heroin overdose patients (group A) and in 53 patients with cardiac arrest caused by other poisonings (group B). Three (16%) vs. six (11%) patients were discharged alive (group A vs. B, respectively). The survivors in group A had an Emergency Medical Service (EMS)-witnessed cardiac arrest or the Emergency Dispatching Centre was called before the arrest occurred. There was no statistically significant difference between the two groups in terms of survival. Survivors in both groups suffered from acute renal failure (two), hypoglycaemia (four) and hypothermia (three).

CONCLUSION

Survival after cardiac arrest caused by heroin overdose is possible if the arrest is EMS witnessed or the Emergency Dispatching Centre is called before the cardiac arrest occurs. In comparison with cardiac arrests caused by other poisonings, there was no difference in survival. The incidence and mechanism of hypoglycaemia should be examined in further studies.

Fatal poisoning in Nordic drug addicts in 2002

The present study from 2002 includes medicolegally examined fatal poisonings among drug addicts in the five Nordic countries: Denmark, Finland, Iceland, Norway and Sweden. A common definition "drug addict" is applied by the participating countries. The number of deaths, age, sex, place of death, main intoxicant and other drugs present in the blood are recorded in order to obtain national data, as well as comparable Nordic data and data comparable to earlier studies from 1997 and 1991. The Icelandic results are commented on separately due to the low number of cases. The most fatal overdoses are seen in Norway, in both the death rate (number per 100,000 inhabitants=8.44) and in absolute number (n=232). The comparable figures for the other four countries are Denmark 5.43 (n=175), Iceland 3.6 (n=6), Finland 2.93 (n=94) and Sweden 2.56 (n=136). In earlier studies from 1991 and 1997, the highest death rate is seen in Denmark, with Norway as number two. Denmark is the only country where the death rate decreases from 1997 to 2002. A relatively large increase in deaths in the younger age groups (<30 years) is noted from 1997 to 2002, except in Denmark, where only a small increase in overdose deaths in very young people (15-19 years) is observed. Females account for 12-20% of the overdoses (three out of six deaths in Iceland). Relatively fewer deaths are recorded in the capital areas in 2002 than in 1997 and 1991, suggesting more geographically widespread drug use in the Nordic countries. Heroin/morphine is the single most frequently encountered main intoxicant, varying from 10% of the cases in Finland to 72% of the cases in Norway. Finland differs from the other countries in that a high percentage of the fatal overdoses in Finland are not caused by an illicit drug; buprenorphine overdoses are seen, and relatively few deaths resulting from heroin are seen. Methadone is the main intoxicant in 41% of the Danish overdose cases, 15% of the Norwegian cases, 4% of the Swedish cases and none of the Finnish overdose cases, an observation probably linked to different national prescription rules for methadone. The analytical screening reveals extended polydrug use. Frequently seen substances, in addition to the main intoxicant are amphetamine, tetrahydrocannabinol (THC), benzodiazepines and ethanol.

Isotopic pattern and accurate mass determination in urine drug screening by liquid chromatography/time-of-flight mass spectrometry

An efficient method was developed for toxicological drug screening in urine by liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry. The method relies on a large target database of exact monoisotopic masses representing the elemental formulae of reference drugs and their metabolites. Mass spectral identification is based on matching measured accurate mass and isotopic pattern (SigmaFit) of a sample component with those in the database. Data post-processing software was developed for automated reporting of findings in an easily interpretable form. The mean and median of SigmaFit for true-positive findings were 0.0066 and 0.0051, respectively. The mean and median of mass error absolute values for true-positive findings were 2.51 and 2.17 ppm, respectively, corresponding to 0.65 and 0.60 mTh. For routine screening practice, a SigmaFit tolerance of 0.03 and a mass tolerance of 10 ppm were chosen. Ion abundance differences from urine extracts did not affect the accuracy of the automatically acquired SigmaFit or mass values. The results show that isotopic pattern matching by SigmaFit is a powerful means of identification in addition to accurate mass measurement.

Relation of postmortem blood alcohol and drug concentrations in fatal poisonings involving amitriptyline, propoxyphene and promazine

Drugs and alcohol often occur together in fatal poisonings, complicating the process of determining the cause of death. Especially when found in concentrations generally regarded as toxic but not lethal, the question arises whether the combination of sublethal amounts was the likely cause of death. In this study, we examined poisoning deaths involving amitriptyline, propoxyphene and promazine, which are, after benzodiazepines, the most frequently occurring drugs in Finnish alcohol-related poisonings. From the forensic toxicology database, covering the years 1995-2002, we extracted 332 fatal poisonings, calculated median blood alcohol and drug concentrations, constructed concentration-concentration and concentration-response curves and evaluated the significance of the presence of therapeutic amounts of benzodiazepines. Median amitriptyline and propoxyphene concentrations were lower in alcohol-related cases than in clean drug poisonings. Correspondingly, the median blood alcohol concentrations in all drug-related poisonings were 1.5-2.2 mg/g lower than that found in clean alcohol poisonings. Alcohol concentration proved to be a more sensitive indicator of alcohol-drug interaction than drug concentration. This result suggests that when alcohol is present, relatively small overdoses of the studied drugs may result in fatal poisoning. In this context, fatal drug and alcohol concentrations and the issue of determining the most important agent in fatal drug-alcohol intoxications are discussed.

CYP2D6 and CYP2C19 genotypes and amitriptyline metabolite ratios in a series of medicolegal autopsies

In a series of 202 postmortem toxicology cases, the CYP2D6 and CYP2C19 genes were genotyped, and the concentrations of amitriptyline (AT) and six metabolites were analyzed. The polymorphic CYP2D6 and CYP2C19 genes encode enzymes participating in the metabolism of several potentially toxic drugs, and mutations in these genes may lead to adverse drug reactions, possibly even intoxications. AT was chosen as the substrate of interest because it is mainly metabolized by these enzymes, is considered relatively toxic, and ranks among the major causes of fatal drug poisoning in Finland. Our objective was to evaluate genetically determined interindividual variation in conjunction with metabolite ratios of drugs found in toxicological analysis in a series of medicolegal autopsies. Positive correlations were found between the proportion of trans-hydroxylated metabolites and the number of functional copies of CYP2D6 and between the proportion of demethylated metabolites and the number of functional copies of CYP2C19. None of the accidental or undetermined AT poisonings coincided with the CYP2D6 or CYP2C19 genotype which predicts a poor metabolizer phenotype. However, an unusually high femoral blood concentration of AT, 60mg/l, was found in one suicide case with no functional CYP2D6 genes. Our study shows a concordance of AT metabolite patterns with CYP2D6 and CYP2C19 genotypes in the presence of confounding factors typical for postmortem material. This result demonstrates the feasibility of postmortem pharmacogenetic analysis and supports the dominant role of genes in drug metabolism.

Newer antidepressants: evaluation of fatal toxicity index and interaction with alcohol based on Finnish postmortem data

Finnish postmortem toxicology data from 1995 to 2002 was analyzed to obtain improved estimates of fatal toxicity indices for the newer antidepressants and to evaluate their interaction with alcohol. Altogether 284 fatal poisonings were attributed to 12 different newer antidepressants. Venlafaxine, mianserin, moclobemide, and mirtazapine were responsible for significantly more deaths than expected from their sales. Their fatal toxicity indices were higher than those of selective serotonin reuptake inhibitors (SSRIs) but lower than those of tricyclic antidepressants. In fatal poisonings involving alcohol in combination with venlafaxine, mianserin, moclobemide, or mirtazapine, the median blood alcohol concentration (BAC) ranged from 2.35 to 2.7 mg/g, whereas in those involving alcohol in combination with citalopram or fluoxetine the median BAC was 2.9 and 3.4 mg/g, respectively. The BAC was significantly lower in venlafaxine-related deaths than in those involving fluoxetine or citalopram. We conclude that among the newer antidepressants differences are present both in toxicity and in interaction potential with alcohol. The SSRIs appear to present a low risk of fatal poisoning when taken alone or in combination with alcohol, whereas venlafaxine is associated with an elevated risk.

Infant botulism acquired from household dust presenting as sudden infant death syndrome

Clostridium botulinum type B was detected by multiplex PCR in the intestinal contents of a suddenly deceased 11-week-old infant and in vacuum cleaner dust from the patient's household. C. botulinum was also isolated from the deceased infant's intestinal contents and from the household dust. The genetic similarity of the two isolates was demonstrated by pulsed-field gel electrophoresis and randomly amplified polymorphic DNA analysis, thereby confirming that dust may act as a vehicle for infant botulism that results in sudden death.

Application of Accurate Mass Measurement to Urine Drug Screening

Poor availability of reference standards for designer drugs, metabolites, and new substances prevents toxicology laboratories from rapidly responding to the changing analytical challenges of drug abuse. A novel screening approach comprising determination of accurate masses of sample components and comparison of these with databases of theoretical monoisotopic masses is described. Using liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS), a routine mass search window of 20-30 ppm was applied to urine samples. The ultimate reference technique, liquid chromatography-Fourier transform mass spectrometry (LC-FTMS), was capable of confirming the findings within a 3 ppm mass accuracy. Using a target database of 7640 compounds, the number of potential elemental formulas ranged from one to three with LC-TOFMS, and it was always one with LC-FTMS. In contrast to ordinary techniques requiring primary reference standards, the formula-based databases can be updated instantly with fresh numeric data from scientific literature and authority sources.

Analysis of Street Drugs in Seized Material without Primary Reference Standards

A novel approach was used to analyze street drugs in seized material without primary reference standards. Identification was performed by liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS), essentially based on accurate mass determination using a target library of 735 exact monoisotopic masses. Quantification was carried out by liquid chromatography/chemiluminescence nitrogen detection (LC/CLND) with a single secondary standard (caffeine), utilizing the detector's equimolar response to nitrogen. Sample preparation comprised dilution, first with methanol and further with the LC mobile phase. Altogether 21 seized drug samples were analyzed blind by the present method, and results were compared to accredited reference methods utilizing identification by gas chromatography/mass spectrometry and quantification by gas chromatography or liquid chromatography. The 31 drug findings by LC/TOFMS comprised 19 different drugs-of-abuse, byproducts, and adulterants, including amphetamine and tryptamine designer drugs, with one unresolved pair of compounds having an identical mass. By the reference methods, 27 findings could be confirmed, and among the four unconfirmed findings, only 1 apparent false positive was found. In the quantitative analysis of 11 amphetamine, heroin, and cocaine findings, mean relative difference between the results of LC/CLND and the reference methods was 11% (range 4.2-21%), without any observable bias. Mean relative standard deviation for three parallel LC/CLND results was 6%. Results suggest that the present combination of LC/TOFMS and LC/CLND offers a simple solution for the analysis of scheduled and designer drugs in seized material, independent of the availability of primary reference standards.

Simultaneous screening for 238 drugs in blood by liquid chromatography-ion spray tandem mass spectrometry with multiple-reaction monitoring

A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method is presented for the qualitative screening for 238 drugs in blood samples, which is considerably more than in previous methods. After a two-step liquid-liquid extraction and C(18) chromatography, the compounds were introduced into a triple quadrupole mass spectrometer equipped with a turbo ion spray ion source operating in the positive ionization mode. Identification was based on the compound's absolute retention time, protonated molecular ion, and one representative fragment ion obtained by multiple reaction monitoring (MRM) at an individually selected collision energy of 20, 35, or 50 eV. The limit of detection (LOD) for the majority of the compounds (80%) was < or = 0.05 mg/l, ranging from 0.002 mg/l (e.g., antihistamines) to 5 mg/l (acidic compounds), and for malathion it was 10 mg/l. The LOD values were sufficiently low to allow the majority of compounds to be detected at therapeutic concentrations in the blood.

Toxicological Screening with Formula-Based Metabolite Identification by Liquid Chromatography/Time-of-Flight Mass Spectrometry

An analytical procedure was evaluated for the comprehensive toxicological screening of drugs, metabolites, and pesticides in 1-mL urine samples by TurboIon spray liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) in the positive ionization mode and continuous mass measurement. The substance database consisted of exact monoisotopic masses for 637 compounds, of which an LC retention time was available for 392. A macroprogram was refined for extracting the data into a legible report, utilizing metabolic patterns and preset identification criteria. These criteria included +/-30 ppm mass tolerance, a +/-0.2-min window for absolute retention time, if available, and a minimum area count of 500. The limit of detection, determined for 90 compounds, was <0.1 mg/L for 73% of the compounds studied and >1.0 mg/L for 6% of the compounds. For method comparisons, 50 successive autopsy urine samples were analyzed by this method, and the results confirmed by gas chromatography/mass spectrometry (GC/MS). Findings for parent drugs were consistent with both methods; in addition, LC/TOFMS regularly revealed apparently correct findings for metabolites not shown by GC/MS. Mean and median mass accuracy by LC/TOFMS was 7.6 and 5.4 ppm, respectively. The procedure proved well-suited for tentative identification without reference substances. The few false positives emphasized the fact that all three parameters, exact mass, retention time, and metabolite pattern, are required for unequivocal identification.

Fatal drug poisonings: medico-legal reports and mortality statistics

The entire fatal drug poisoning panorama in Finland is considered in terms of three catergories: accidental, self-inflicted and undetermined (whether accidental or with intent to harm) deaths. The study material consisted of all 500 deaths in 1997 that medical examiners, after examination(s) at the Forensic Toxicology Division (FTD) of the Department of Forensic Medicine, University of Helsinki, officially certified as resulting from drug poisoning. These deaths were matched with data on the same deaths registered at Statistics Finland (SF), the national mortality statistics office. The SF register included 72 additional instances of deaths resulting from drug poisoning. In all but two of these cases, the cause-of-death determination was based on a medico-legal inquest with autopsy and forensic toxicological examination(s) and was certified, in most of the cases, as due to the alcohol component in multiple-toxicant combinations. Reclassifying these deaths at SF to the category of drug component is in accordance with current International Classification of Diseases (ICD-10) regulation of coding "to the medicinal agent when combined with alcohol"; the principle and practice, which is recommended to be amended to equalize the status of alcohol and drug when explicitly stated by a forensic examiner as the principal toxicant in combined poisonings. With regard to manner-of-death, the agreement rates between medico-legally proven deaths from drug poisoning and those registered at SF were 79.8% for accidents, 98.5% for suicides and 0% (nil) for undetermined deaths, at the level of three-character external cause codes (E-code). All deaths originally certified as undetermined were re-assigned, most frequently to the category of accidental death. Since within an advanced and sophisticated medico-legal system, a medical examiner's evidence-based statement, even when the conclusion reached is undetermined (as to intent), should be taken as a compelling argument, the practice of reclassification cannot be considered advisable because assembled information is lost. Concerning the assigned drug-specific groups, the agreement according to the manner-of-death between certifications and registrations was fairly good. From among the accidents, however, opioid poisonings were re-assigned in 11 (29.7%) cases, mostly to the drug abuse/dependence categories, i.e. they were considered as natural deaths by the statistics office. The drug-specific observations were possible only by using the codes from the Anatomical Therapeutic Chemical (ATC) classification of drugs. This is why the incorporation of ATC codes into the ICD system, whenever reasonable, is recommended.

Post-mortem SNP analysis of CYP2D6 gene reveals correlation between genotype and opioid drug (tramadol) metabolite ratios in blood

Tramadol is an opioid drug metabolised in phase I by cytochrome P450 (CYP) enzymes, of which CYP2D6 is mainly responsible for the O-demethylation of tramadol, but is not involved in N-demethylation. Defects in the genes encoding drug metabolising enzymes (DMEs) may lead to adverse drug effects, even to death. To aid interpretation of the forensic toxicology results, we studied how the genetic variation of the CYP2D6 gene is reflected in tramadol metabolite ratios found in post-mortem samples. In 33 Finnish autopsy cases where tramadol was found, we analysed both the CYP2D6 genotype and the concentrations of tramadol and its metabolites O- and N-demethyltramadol. As expected, we found a correlation between the number of functional CYP2D6 alleles and the ratio of tramadol to O-demethyltramadol. We also found a correlation between the number of functional alleles and the ratio of tramadol to N-demethyltramadol. This can be explained by the complementary nature of the two main tramadol demethylation pathways. No known CYP2D6 inhibitors were associated with exceptional metabolic ratios. Furthermore, no accidental tramadol poisonings were associated with a defective CYP2D6 gene. Our results on the tramadol are among the first to demonstrate that genetic variation in drug metabolising enzymes can be analysed in post-mortem blood, and that it correlates well with the parent drug to metabolite ratios. The results also suggest that genetic factors play, in general, a dominant role over other factors in the metabolism of individual drugs.

Register based monitoring shows decreasing socioeconomic differences in Finnish perinatal health

STUDY OBJECTIVE

Several studies on differences in infant outcome by socioeconomic position have been done, but these have usually been based on ad hoc data linkages. The aim of this paper was to investigate whether socioeconomic differences in perinatal health in Finland could be regularly monitored using routinely collected data from one single register.

DESIGN AND SETTING

Since October 1990, the Finnish Medical Birth Register (MBR) has included data on maternal occupation. A special computer program that converted the occupation name into an occupational code and into a socioeconomic position was prepared. Perinatal health was measured with five different indicators. The Finnish MBR data for years 1991 to 1999 (n=565 863 newborns) were used in the study. The study period was divided into three, three year periods to study time trends.

RESULTS

An occupational code was derived for 95% of women, but it was not possible to define a socioeconomic position for 22% of women, including, for example, students and housewives (the group "Others"). For the rest, the data showed socioeconomic differences in all perinatal health indicators. Maternal smoking explained up to half of the excess risk for adverse perinatal outcome in the lowest socioeconomic group. The socioeconomic differences narrowed during the 1990s: infant outcome improved in the lowest socioeconomic group, but remained at the same level or even deteriorated in other groups. When comparing the lowest group with the highest group, the odds ratios (OR) adjusted for maternal background characteristics at least halved for prematurity (from 1.32 (95% confidence intervals 1.24 to 1.43) in 1991-1993 to 1.16 (1.08 to 1.25) in 1997-1999), for low birth weight (from 1.49 (1.36 to 1.63) to 1.25 (1.17 to 1.40)), and for perinatal mortality (from 1.79 (1.44 to 2.21) to 1.33 (1.07 to 1.66)).

CONCLUSIONS

Social inequality in perinatal health outcomes exists in Finland, but seems to have diminished in the 1990s. These data showed that routinely collected birth register data provide a good source for studies on socioeconomic health differences in the perinatal period, but that uncertainty, mainly attributable to the large group of women with difficult to classify socioeconomic status, remains.

Precise gas chromatography with retention time locking in comprehensive toxicological screening for drugs in blood

The long-term precision of three retention parameters, the absolute retention time (RT), the relative retention time related to dibenzepin (RRT), and the internal retention index based on the alkylfluoroaniline series (RI), were studied with 14 basic drugs on HP-5 and DB-17 columns with and without the use of the retention time locking option (RTL). Using the constant flow mode in all experiments, the RTL method was found to produce superior precision with all three retention parameters compared to the non-RTL method on each column. The results showed that RTL offers a significant advantage within a single instrument method, not only between methods, with CV<0.1% by RRT. Consequently, a dual-column gas chromatographic procedure with nitrogen-phosphorus detection was described for comprehensive screening for basic drugs in 1-ml whole blood samples. The method consisted of one-step liquid-liquid extraction with butyl acetate, identification using RRT in the RTL mode, and quantification based on single point calibration. The method allowed reliable screening and quantification of 124 basic drugs at therapeutic and toxic concentration levels in autopsy blood.

Screening for basic drugs in 2-mL urine samples by dual-plate overpressured layer chromatography and comparison with gas chromatography-mass spectrometry

A dual-plate overpressured layer chromatography (OPLC) method was evaluated for broad-scale screening of basic drugs in 2-mL autopsy urine samples. Extraction was carried out by mixed-mode solid-phase extraction, and identification was based on automated comparison of corrected Rf values (hRfc) and in situ UV spectra with library values by dedicated software. The day-to-day precision of hRfc values was good in both OPLC1 and OPLC2 systems with median relative standard deviations of 2.4% and 3.4%, respectively. Both Rf and hRfc values were independent of the amount of analyte (0.5-10 microg) applied to the plate. Detection limits were determined for 47 drug substances in 2-mL urine samples, and they varied between 0.05 and 3.5 mg/L with a median of 1.0 mg/L. The performance of OPLC was evaluated by analyzing 30 autopsy urine samples by both OPLC and gas chromatography-mass spectrometry (GC-MS). The majority of findings by OPLC were in agreement with GC-MS. Some substances with low concentrations were not detected by OPLC, whereas GC-MS failed to detect a few polar substances. The OPLC method thus provides an alternative for current planar and column liquid chromatographic drug screening methods with the possibility of lowering detection limits by using a larger sample size.

Interaction of alcohol and drugs in fatal poisonings

In Finnish data from 1995-2000, 1006 fatal poisonings due to alcohol (ethanol), a single drug or both were statistically analysed in retrospect to evaluate the interaction between alcohol and drugs. In 53% of these cases, low concentrations of some common benzodiazepines were present. The median postmortem blood alcohol concentration (BAC) was 3.3 percent per thousand (w/w) in the 615 alcohol poisonings, but significantly lower, ranging from 1.3 to 1.7 percent per thousand, when promazine, doxepin, amitriptyline or propoxyphene were found together with alcohol. When levomepromazine, temazepam or zopiclone were present, the median BAC was also significantly lower, 2.5-2.7 percent per thousand. Citalopram and diltiazem did not exhibit a significant effect. The median BAC was significantly lower in cases with high concentrations than in those with low concentrations of a drug (excluding citalopram), suggesting a positive concentration-effect relationship. Fatal toxicity indices (FTIs) were calculated by relating the number of deaths caused by a drug to the corresponding sales figures. Promazine had an extremely high FTI, followed by levomepromazine, propoxyphene, doxepin and amitriptyline. The other drugs had relatively low FTIs. The results reflect not only the acute toxicity of a given drug-alcohol combination but also the manners of use and abuse of these drugs.