Oxycodone-Related Deaths: The Significance of Pharmacokinetic and Pharmacodynamic Drug Interactions

BACKGROUND AND OBJECTIVES

Oxycodone is frequently prescribed as well as detected in postmortem cases. Concurrent use of pharmacodynamically or pharmacokinetically interacting drugs can cause adverse effects or even fatal intoxication. The aims of this study were to investigate differences in prescriptions for and toxicological findings of pharmacodynamically and pharmacokinetically interacting drugs in fatal oxycodone-related intoxications and other causes of death. We also aimed to investigate the differences in prevalence of oxycodone prescriptions, and the detected postmortem oxycodone concentrations between fatal oxycodone-related intoxications and other causes of death.

METHODS

Forensic autopsy cases (2012-2018) where oxycodone was identified in femoral blood (n = 1236) were included. Medical history and prescription data were retrieved from national databases and linked to the forensic toxicology findings.

RESULTS

Oxycodone-related deaths were found to have higher blood concentrations of oxycodone (median 0.30 µg/g vs. 0.05 µg/g) and were less likely to have a prescription for oxycodone (OR 0.62) compared to nonintoxication deaths. Pharmacodynamically interacting drugs were prescribed in 79% and found in blood in 81% of the cases. Pharmacokinetically interacting drugs were rarely prescribed (1%). Oxycodone-related deaths were more likely to have prescriptions for a pharmacodynamically interacting drug (OR 1.7) and more often have co-findings of one or multiple pharmacodynamically interacting drugs (OR 5.6).

CONCLUSION

The results suggest that combined use of oxycodone and pharmacodynamically interacting drugs is associated with oxycodone-related death and that non-medical use of oxycodone is a potential risk factor for oxycodone-related intoxication.

The Importance of BHB Testing on the Post-Mortem Diagnosis of Ketoacidosis

Although beta-hydroxybutyrate (BHB) analysis has proved its importance in forensic pathology, its effects on cause-of-death diagnostics are unaddressed. Therefore, this study aims at evaluating the effects of BHB analysis on the number of deaths by DKA (diabetes ketoacidosis), AKA (alcoholic ketoacidosis), HHS (hyperosmolar hyperglycaemic state), hypothermia, diabetes, alcoholism, and acidosis NOS (not otherwise specified). All 2900 deaths from 2013 through 2019 in which BHB was analysed at the National Board of Forensic Medicine, and 1069 DKA, AKA, HHS, hypothermia, diabetes, alcoholism, and acidosis cases without BHB analysis were included. The prevalence of BHB-positive cases for each cause of death, and trends and proportions of different BHB concentrations, were investigated. The number of BHB analyses/year increased from 13 to 1417. AKA increased from three to 66 and acidosis from one to 20. The deaths from alcoholism, DKA, and hypothermia remained stable. It is unclear why death from alcoholism remained stable while AKA increased. The increase in unspecific acidosis deaths raises the question why a more specific diagnosis had not been used. In conclusion, BHB analysis is instrumental in detecting AKA and acidosis. The scientific basis for the diagnosis of DKA and hypothermia improved, but the number of cases did not change.

Current Evidence on Abuse and Misuse of Gabapentinoids

This review summarizes current evidence on the abuse and misuse of the gabapentinoids pregabalin and gabapentin. Pharmacovigilance studies, register-based studies, surveys, clinical toxicology studies, and forensic toxicology studies were identified and scrutinized with the goal to define the problem, identify risk factors, and discuss possible methods to reduce the potential for abuse and misuse. Studies found that gabapentinoids are abused and misused and that individuals with a history of psychiatric disorders or substance use disorder seem to be at high risk. Moreover, some evidence supports the notion that patients with opioid use disorders may be at an increased risk of abusing gabapentinoids. Available evidence also suggests that abuse and misuse are more frequent in users of pregabalin compared with users of gabapentin. Health professionals and prescribers should be aware of the risk for misuse of pregabalin and gabapentin, which eventually could lead to abuse, substance dependence, and intoxications. Prescribing to patients belonging to risk populations such as those with psychiatric disorders or substance use disorder should be avoided if possible and, if prescribed, signs of misuse and abuse should be monitored.

False negative results in testosterone doping in forensic cases: Sensitivity of the urinary detection criteria T/E and T/LH

At the Swedish national forensic toxicology laboratory, a measured testosterone/epitestosterone (T/E) ratio ≥ 12 together with testosterone/luteinizing hormone (T/LH) in urine > 400 nmol/IU is considered as a proof of exogenous testosterone administration. However, according to the rules of the World Anti-Doping Agency (WADA), samples with T/E ratio > 4 are considered suspicious and shall be further analysed by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) to confirm the origin of testosterone and its metabolites. The aim of this study was to investigate the possibility of false negative results and to estimate the frequency of negative results using the current criteria for detection of abuse of testosterone in forensic investigations. Urine and serum samples were collected by the police at suspected infringement of the doping law in Sweden. Fifty-eight male subjects were included in the study. Urinary testosterone was determined by gas chromatography-mass spectrometry (GC-MS), serum testosterone and LH-by immunoassay. The origin of testosterone and its metabolites was confirmed by means of GC-C-IRMS. Twenty-six of the 57 analysed subjects tested positive for exogenous testosterone using the criteria T/E ≥ 12 combined with T/LH > 400 nmol/IU. The IRMS analyses confirmed 47 positives; thus, 21 were considered false negatives. Negative predictive value was 32% (95% confidence interval [CI]: 16%-50%) and sensitivity 55%. No false positive subjects were found. The number of false negative cases using the current criteria for the detection of testosterone abuse and hence the low sensitivity indicates a need to discuss introduction of new strategies in forensic doping investigations.

Determination of testosterone in serum and saliva by liquid chromatography-tandem mass spectrometry: An accurate and sensitive method applied on clinical and forensic samples

A highly sensitive and accurate electrospray liquid chromatography tandem-mass spectrometry (ESI-LC-MS/MS) method for determination of testosterone in human serum and saliva was developed and validated. Accurate quantification of testosterone in human matrices is essential in diagnosis and management of androgen status in men, women and children, and in forensic investigations of suspected abuse of anabolic androgenic steroids. Chromatography was performed on an HSS-T3 C18 column with a total run-time of 5.5 min. The tandem mass spectrometry was operated in positive electrospray ionization mode with multiple reaction monitoring. Serum and saliva samples of 200 μL, were prepared by solid-phase extraction using a 96-well plate following precipitation with 200 μL methanol. ¹³C labeled testosterone was used as internal standard for quantification. The standard curve was linear within the range of 4-1000 pg/mL and the limit of quantification of both serum and salivary testosterone was 4 pg/mL. Accuracy were 99-101 % and 93-95 % with between-run imprecision in serum and saliva, respectively, and inter- and intra-assay coefficients of variation were less than 9.2 %. The method proved to be applicable for determination of testosterone over a wide range of concentrations in serum and saliva samples from clinical patients with various androgen disorders, healthy male and female adults as well as from forensic cases.

Use of Lisdexamfetamine or Amphetamine? Interpretation of Chiral Amphetamine Analyses

Amphetamine is frequently detected in forensic toxicological cases. Differentiating between the two isomers of amphetamine (d-amphetamine and l-amphetamine) and determining their relative proportion is fundamental to correctly interpret the results of toxicological analyses. The aim of this study was to examine the profile of amphetamine as well as storage stability of the isomers in authentic samples from patients chronically treated with lisdexamfetamine (LDX), the most prescribed medical amphetamine product in Sweden. Blood and urine samples were collected from 18 patients. The samples were analyzed with an achiral (racemate) method for quantification of amphetamine and with a chiral method to determine the proportion of each isomer of amphetamine. The median daily dose of LDX was 40 mg (range, 20-70 mg). The median amphetamine concentration was 0.06 µg/g (range, 0.02-0.15 µg/g) in blood and 6 µg/mL (range, 1-22 µg/mL) in urine. Only d-amphetamine was found in the blood and urine samples from the included patients. Furthermore, no formation of l-amphetamine occurred during storage for three months at 4°C, nine months at -20°C and three freeze-thaw cycles. The results from this study may be helpful in the interpretation of whether the source of identified amphetamine in biological samples are from LDX drug intake or not.

Evaluating the hip-flask defence using analytical data from ethanol and ethyl glucuronide. A comparison of two models

AIM

Claimed intake of alcohol after a traffic incident, called the hip-flask defence, can be objectively assessed by different methods. One of them is the use of two consecutive ethanol concentrations in urine and the ratio between ethanol concentrations in urine and blood. Another one is the concentrations of ethyl glucuronide (EtG) and ethyl sulphate (EtS) in blood and their ratio to ethanol. The experimental basis for both these models is from single dose studies only. The aim of this study was therefore to describe the kinetics of ethanol, EtG and EtS after ingestion of two repeated doses of ethanol and to investigate the usefulness of the different models for the assessment of the hip-flask defence.

METHODS

Thirty-five subjects ingested a first dose of 0.51 g of ethanol per kilo body weight, and two hours later a second dose (the hip-flask drink) of 0.25, 0.51 or 0.85 g of ethanol per kilo body weight. Ten urine and 17 blood samples were collected and analysed for ethanol, EtG and EtS using fully validated methods. It was investigated if all subjects fulfilled the criteria for recent drinking, according to the two different models, when using the samples collected 180-240 minutes after start of first dose drinking. According to the first model, increase in urinary ethanol concentrations and a ratio UAC/BAC below 1.3 indicated recent drinking. According to the second model, increase in blood EtG concentrations and a ratio ethanol (g/kg)/EtG (mg/L) above 1 indicated recent drinking.

RESULTS

All subjects in the high dose group fulfilled all criteria for recent drinking. One subject in the medium dose group and nine subjects in the low dose group failed to show increasing UAC and/or a UAC/BAC ratio below 1.3. One subject in the low dose group failed to show increasing concentrations of blood EtG, but all subjects showed a ratio ethanol/EtG above 1.

CONCLUSIONS

The present study showed, by the use of experimental data, that both two models used to investigate the hip-flask defence can be used, but only when the hip-flask dose is sufficiently high.

Do patients or their physicians more accurately assess long-term risk associated with hypertension? A population-based study

Objective: To compare the assessments of 10-year probability by patients and their physicians of cardiovascular complications of hypertension with actual outcomes.Design: Patients with uncomplicated hypertension treated with at least one antihypertensive drug at inclusion were followed for 10 years through mandatory national health registers.Setting: 55 primary health care centres, 11 hospital outpatient clinics in SwedenPatients: 848 patient, 212 physicians.Main outcome measures: Patients and physicians estimated the probability of hypertension-related complications with treatment (death, heart failure, acute myocardial infarction/AMI, and stroke) for each patient in 848 pairs. Estimates were compared with the clinical outcomes 10 years later using data from the Mortality Register and the National Patient Register.Results: Patients were significantly better (p < 0.001) than their physicians in estimating the average probability of heart failure compared with actual outcome data (14% vs. 24%, outcome 15%), AMI (16% vs. 26%, outcome 8%), and stroke (15% vs. 25%, outcome 11%). Patients were significantly worse (p < 0.001) at estimating the average probability of death (10% vs. 18%, actual outcome 20%). Neither the patients nor the physicians were able to distinguish reliably between low-risk and high-risk patients after adjustment for age and sex.Conclusions: Patients were better than their physicians in estimating the average probability of morbidity due to hypertension. Both the patients and their attending physicians had difficulty in estimating the individual patient's risk of complications. The results support the use of evidence-based tools in consultations for assessing the risk of cardiovascular complications associated with hypertension.Key points • Shared decision making relies on a common understanding of risks and benefits. Tools for risk assessment of hypertension have been introduced in the last two decades. • Without tools for risk assessment, both patients and physicians had difficulties in estimating the individual patient's risk of cardiovascular morbidity. • Patients were better than physicians in estimating actual average cardiovascular morbidity due to hypertension during a follow-up of 10 years. • The results support the use of evidence-based tools in consultations for assessing the risk of cardiovascular complications associated with hypertension.

The unknown known: non-cardiogenic pulmonary edema in amlodipine poisoning, a cohort study

Context: Amlodipine is the most common calcium channel blocker (CCB) on the Swedish market, and poison center (PC) consultations for amlodipine overdoses are increasing. The clinical picture is dominated by vasodilation with relative preservation of cardiac function. CCBs selectively dilate vessels on the afferent side of the capillary network which, in states of preserved or increased blood flow may lead to edema formation, including non-cardiogenic pulmonary edema (NCPE). This complication has been considered rare in CCB poisoning. In this cohort study of nineteen amlodipine poisonings with high amlodipine blood levels, the incidence and clinical significance of NCPE in severe amlodipine poisoning are explored.Methods: During 2017-2018 the Swedish PC prospectively encouraged the gathering of blood samples in amlodipine poisonings with symptoms requiring treatment with inotropes or vasopressors. Samples were sent by mail to the Forensic Toxicology Division at the Swedish National Board of Forensic Medicine for screening and quantification of relevant toxicants. Patients with blood amlodipine levels >0.25 µg/mL were included in a cohort whose case details were gathered from medical records and PC-case notes with a special focus on signs of NCPE.Results: Nineteen patients met the blood amlodipine inclusion criteria. Four (21%) died and one patient was treated with VA-ECMO. Nine patients developed NCPE defined as a need for positive pressure ventilation (PPV) while having an echocardiographically normal left ventricular function.Conclusion: In this prospective cohort study of consecutive and analytically confirmed significant amlodipine poisonings NCPE was a common finding occurring in 47% of the whole cohort and in 64% of patients who did not go on to develop complete hemodynamic collapse.

Non-prescribed use of psychoactive prescription drugs among drug-impaired drivers in Sweden

AIMS

To determine the prevalence of non-prescribed drug use among subjects suspected of drug-impaired driving with a psychoactive prescription drug, and to identify associated factors.

METHODS

Subjects investigated for drug-impaired driving in Sweden during 2006-2009 with a confirmed intake of diazepam, flunitrazepam, tramadol, zolpidem or zopiclone were identified using the Swedish Forensic Toxicology Database. Information on dispensed prescription drugs was retrieved from the Swedish Prescribed Drug Register. Non-prescribed use was our outcome, defined as a psychoactive prescription drug intake confirmed by toxicological analysis in a subject by whom it was not dispensed in the 12 months preceding the sampling. Prevalence proportions were calculated for each drug and logistic regression was used to identify associated factors.

RESULTS

In total, 2225 subjects were included. The median age (range) was 34 (15-80) years and 1864 (83.8%) subjects were male. Non-prescribed use was found in 1513 subjects (58.7%); for flunitrazepam 103 (76.3%), diazepam 1098 (74.1%), tramadol 192 (40.3%), zopiclone 60 (29.7%), and zolpidem 60 (21.2%) subjects, respectively. Younger age and multiple-substance use were associated with non-prescribed use, whereas ongoing treatment with other psychoactive drugs was negatively associated with non-prescribed use.

CONCLUSIONS

Non-prescribed use of psychoactive prescription drugs was common in subjects suspected of drug-impaired driving and was more frequent for benzodiazepines and tramadol compared to zolpidem and zopiclone. The young and multi-substance users were more likely, whereas subjects with ongoing prescribed treatment with other psychoactive drugs were less likely, to use non-prescribed drugs.

Demographics and post-mortem toxicology findings in deaths among people arrested multiple times for use of illicit drugs and/or impaired driving

BACKGROUND

Multiple arrests for use of illicit drugs and/or impaired driving strongly suggests the existence of a personality disorder and/or a substance abuse problem.

METHODS

This retrospective study (1993-2010) used a national forensic toxicology database (TOXBASE), and we identified 3943 individuals with two or more arrests for use of illicit drugs and/or impaired driving. These individuals had subsequently died from a fatal drug poisoning or some other cause of death, such as trauma.

RESULTS

Of the 3943 repeat offenders 1807 (46%) died from a fatal drug overdose and 2136 (54%) died from other causes (p<0.001). The repeat offenders were predominantly male (90% vs 10%) and mean age of drug poisoning deaths was 5 y younger (mean 35 y) than other causes of death (mean 40 y). Significantly more repeat offenders (46%) died from drug overdose compared with all other forensic autopsies (14%) (p<0.001). Four or more drugs were identified in femoral blood in 44% of deaths from poisoning (drug overdose) compared with 18% of deaths by other causes (p<0.001). The manner of death was considered accidental in 54% of deaths among repeat offenders compared with 28% for other suspicious deaths (p<0.001). The psychoactive substances most commonly identified in autopsy blood from repeat offenders were ethanol, morphine (from heroin), diazepam, amphetamines, cannabis, and various opioids.

CONCLUSIONS

This study shows that people arrested multiple times for use of illicit drugs and/or impaired driving are more likely to die by accidentally overdosing with drugs. Lives might be saved if repeat offenders were sentenced to treatment and rehabilitation for their drug abuse problem instead of conventional penalties for drug-related crimes.

Influence of UGT2B7, OPRM1 and ABCB1 gene polymorphisms on postoperative morphine consumption

Therapeutic modulation of pain with morphine and other opioids is associated with significant variation in both effects and adverse effects in individual patients. Many factors including gene polymorphisms have been shown to contribute to the interindividual variability in the response to opioids. The aim of this study was to investigate the significance of UGT2B7, OPRM1 and ABCB1 polymorphisms for interindividual variability in morphine-induced analgesia in patients undergoing hysterectomy. The frequency of these polymorphisms was also investigated in forensic autopsies as morphine is also a very commonly abused drug. Blood samples were collected from 40 patients following abdominal hysterectomy, 24 hr after initiation of analgesia through a patient-controlled analgesia (PCA) pump. Samples were genotyped and analysed for morphine and its metabolites. We also genotyped approximately 200 autopsies found positive for morphine in routine forensic analysis. Patients homozygous for UGT2B7 802C needed significantly lower dose of morphine for pain relief. The same trend was observed for patients homozygous for ABCB1 1236T and 3435T, as well as to OPRM1 118A. The dose of morphine in patients included in this study was significantly related to variation in UGT2B7 T802C. Age was significantly related to both dose and concentration of morphine in blood. Regression analysis showed that 30% of differences in variation in morphine dose could be explained by SNPs in these genes. The genotype distribution was similar between the forensic cases and the patients. However, the mean concentration of morphine was higher in forensic cases compared to patients. We conclude that gene polymorphisms contribute significantly to the variation in morphine concentrations observed in individual patients.

Antidepressants and the risk of suicide in young persons--prescription trends and toxicological analyses

OBJECTIVE

To assess trends in the use of antidepressants among young suicides after the warning that these drugs might increase the risk of suicide.

METHOD

Individual data of all 845 suicides in the 10- to 19-year age group in Sweden in the time period 1992-2003 (baseline), and in 2004-2010 (after the warning). Outcome data are prescriptions of antidepressants prior to death and detections of antidepressants in post-mortem toxicology.

RESULTS

After the warning, suicide in this age group increased for five consecutive years (60.5%). The increase occurred among individuals not treated with antidepressants.

CONCLUSION

This study provides further support for the hypothesis that the warning, contrary to its intention, may have increased young suicides by leaving a number of suicidal young persons without treatment with antidepressants.

Prevalence of alcohol and other drugs and the concentrations in blood of drivers killed in road traffic crashes in Sweden

BACKGROUND

Drunk or drug-impaired drivers represent a major public health and societal problem worldwide. Because over 95% of drivers killed on the roads in Sweden are autopsied, reliable information is available about the use of alcohol and/or other drug before the crash.

METHODS

This retrospective 4-year study (2008-2011) used a forensic toxicology database (TOXBASE) to evaluate the concentrations of alcohol and other drugs in blood samples from drivers killed in road-traffic crashes.

RESULTS

The mean age of all victims (N = 895) was 48 ± 20 years, and the majority were male (86%). In 504 drivers (56%), the results of toxicological analysis were negative and these victims were older; mean age (± SD) 47 ± 20 years, than alcohol positive cases (35 ± 14 years) and illicit drug users (34 ± 15 years). In 21% of fatalities, blood-alcohol concentration (BAC) was above the statutory limit for driving (0.2 g/L), although the median BAC was appreciably higher (1.72 g/L). Illicit drugs (mainly amphetamine and cannabis) were identified in ~7% of victims, either alone (2.5%), together with alcohol (1.8%) or a prescription drug (2%). The psychoactive prescription drugs identified were mainly benzodiazepines, z-hypnotics and tramadol, which were found in the blood of 7.6% of crash victims.

CONCLUSIONS

The high median BAC in fatally-injured drivers speaks strongly towards alcohol-induced impairment as being responsible for the crash. Compared with alcohol, the prevalence of illicit and psychoactive prescription drugs was fairly low despite a dramatic increase in the number of drug-impaired drivers arrested by the police after a zero-tolerance law was introduced in 1999.

Altered brain concentrations of citalopram and escitalopram in P-glycoprotein deficient mice after acute and chronic treatment

According to both in vitro and in vivo data P-glycoprotein (P-gp) may restrict the uptake of several antidepressants into the brain, thus contributing to the poor success rate of current antidepressant therapies. The therapeutic activity of citalopram resides in the S-enantiomer, whereas the R-enantiomer is practically devoid of serotonin reuptake potency. To date, no in vivo data are available that address whether the enantiomers of citalopram and its metabolites are substrates of P-gp. P-gp knockout (abcb1ab (-/-)) and wild-type (abcb1ab (+/+)) mice underwent acute (single-dose) and chronic (two daily doses for 10 days) treatment with citalopram (10mg/kg) or escitalopram (5mg/kg) Serum and brain samples were collected 1-6h after the first or last i.p. injection for subsequent drug analysis by an enantioselective HPLC method. In brain, 3-fold higher concentrations of S- and R-citalopram, and its metabolites, were found in abcb1ab (-/-) mice than in abcb1ab (+/+) mice after both acute and chronic citalopram treatments. After escitalopram treatment, the S-citalopram brain concentration was 3-5 times higher in the knockout mice than in controls. The results provide novel evidence that the enantiomers of citalopram are substrates of P-gp. Possible clinical and toxicological implications of this finding need to be further elucidated.

Inhibitory effect of opiates on LPS mediated release of TNF and IL-8

Most patients with advanced cancer experience severe pain and are often treated with opiates. Cancer patients are especially susceptible to opportunistic infections due to treatment with immunosuppressive and cytostatic drugs. Since opiates have been demonstrated to have immunomodulatory effects, it is of clinical importance to evaluate potential differences between commonly used opiates with regard to their effect on the immune system. The aim of this study was to evaluate the effect of morphine, tramadol, fentanyl and ketobemidone on the functioning of the immune system with special reference to TNF and IL-8 release. Method. U-937 cells were preincubated with different concentrations of opioids followed by stimulation with LPS 100 μg/ml for three hours. The effect of opioids on the levels of cytokine mRNA was studied using RT-PCR. Erk and Akt phosphorylation was also measured by Western blot. Results. All opioids with the exception of fentanyl were capable of inhibiting TNF release from U-937 cells. Morphine had no effect on IL-8 release but the effect of other opiates was almost the same as the effect on TNF. All opioids with the exception of fentanyl were capable of inhibiting production of mRNA for TNF and IL-8. The observed effects of opiates were not always reversible by naloxone, suggesting that the effects might be mediated by other receptors or through a non-receptor mediated direct effect. Although preliminary evidence suggests the involvement of Erk and Akt pathways, further studies are needed to unravel the intracellular pathways involved in mediating the effects of opiates. Our data suggests that the order of potency with regard to inhibition of cytokine release is as follows: tramadol > ketobemidone > morphine > fentanyl. Conclusion. Further studies are needed to understand the clinical implications of the observed immunosuppressive effects of tramadol and ketobemidone and to improve opioid treatment strategies in patients with cancer.

ABCB1 gene polymorphisms are associated with fatal intoxications involving venlafaxine but not citalopram

P-glycoprotein (P-gp), encoded by the ABCB1/MDR1 gene, is a drug transporter at the blood-brain barrier. Several polymorphisms in the ABCB1 gene are known to affect the activity and/or expression of P-gp, thereby influencing the treatment response and toxicity of P-gp substrates like citalopram and venlafaxine. In this study, we aimed to investigate the frequency of ABCB1 genotypes in forensic autopsy cases involving these two antidepressants. Further, the distribution of ABCB1 genotypes in deaths related to intoxication was compared to cases not associated to drug intoxication. The study included 228 forensic autopsy cases with different causes and manners of deaths. The ABCB1 single nucleotide polymorphisms (SNPs) G1199A, C1236T, C3435T and G2677T/A for these individuals were determined. The SNPs C1236T and C3435T in venlafaxine-positive cases were significantly different between the intoxication cases and non-intoxications. This was not seen for cases involving citalopram, indicating that the effect of genetic variants might be substrate specific. This novel finding should, however, be confirmed in future studies with larger number of cases.

Toxicological analysis of blood and urine samples from female victims of alleged sexual assault

BACKGROUND

The toxicological analysis of blood and urine samples from victims of alleged sexual assault represents a crucial part of the forensic evidence when this crime is investigated.

MATERIAL AND METHODS

We searched a national forensic toxicology database (TOXBASE) to find cases registered as sexual assault, rape, including date-rape that the police had requested the analysis of ethanol and other drugs. Between 2008 and 2010, N = 1460 such cases met this criteria. After immunological screening of urine or blood samples, all positive results were verified by more specific analytical methods, such as gas chromatography-mass spectrometry (GC-MS) for illicit drugs. A large number of prescription drugs and their metabolites were determined by capillary GC with nitrogen-phosphorous (N-P) detector. GC with flame ionization detector (FID) was used to analyze ethanol and gamma-hydroxybutyrate (GHB) in blood at limits of quantitation (LOQ) of 0.1 g/L and 8 mg/L, respectively.

RESULTS

The average age (± standard deviation) of all victims was 24 ± 10.3 years and 72% were between 15 and 29 years. Ethanol and other drugs were not detected in 31% of cases (N = 459). Blood-ethanol was positive in N = 658 cases at mean, median and highest concentrations of 1.23 g/L, 1.22 g/L and 4.3 g/L, respectively. Ethanol plus drugs were present in N = 188 cases (13%) and one or more other drugs alone in N = 210 cases (14%). Cannabis (marijuana) and amphetamines were the major illicit drugs, whereas diazepam, alprazolam, zopiclone as well as newer antidepressants were the major prescription drugs identified.

CONCLUSIONS

The mean age of victims of sexual assault in Sweden, the proportion of drug positive to drug negative cases, the predominance of ethanol positive cases as well as the types of other drugs showed a remarkably good agreement in two studies spanning a period of 8 years.

Anabolic androgenic steroids in police cases in Sweden 1999-2009

Anabolic Androgenic Steroids (AAS) are considered drugs of abuse and are controlled substances in Sweden since 1999. Traditionally AAS have been used by elite athletes to enhance performance, but in recent years it has become an increasing problem outside elite sport among athletes, bodybuilders and criminals. Use of AAS is associated with psychiatric side effects such as aggression, depression and violent behavior. Supraphysiological doses and long term use can cause serious physical harm such as cardiovascular toxicity and even premature death. We investigated and evaluated the drug analytical findings in forensic cases from suspected perpetrators in cases from the police where a screening for AAS was requested to get information about the prevalence of AAS use and the occurrence of poly-drug abuse. The study was based on samples submitted from the police authorities to the Department of Forensic Toxicology in Sweden during the period 1999-2009. Urines were analyzed by methods based on GC-MS and LC-MS-MS. We also analyzed the prevalence of AAS use at the prison and probation services. A total number of 12,141 urine samples (6362 police cases and 5779 inmates) were analyzed and 33.5% of the cases from the police and 11.5% of the inmates were tested positive for AAS. The users of AAS were mainly in 99.2% men with a mean age of 26.2±6.2 years whereas the women were 29.5±6.5 years old. The most frequently used AAS was nandrolone followed by testosterone and methandienone. Other illicit and licit drugs were detected in 60% of the cases from the police, strongly indicating a frequent poly-drug abuse among users of AAS.

Topical morphine gel in the treatment of painful leg ulcers, a double-blind, placebo-controlled clinical trial: a pilot study

Chronic painful wounds, a major health problem, have a detrimental impact on the quality of life due to associated pain. Some clinical reports have suggested that local administration of morphine could be beneficial. The aim of this study was to evaluate the analgesic effect of topically applied morphine on chronic painful leg ulcers. Twenty-one patients were randomly assigned to receive either morphine or placebo in a randomised, placebo-controlled, crossover pilot study. Each patient was treated four times in total. Pain was measured by the visual analogue score (VAS) before application of gel, directly after and after 2, 6, 12 and 24 hours. Although an overall, clinically relevant, reduction of pain was observed upon treatment with morphine, the difference was not statistically significant. Morphine reduced pain scores more than placebo on treatment occasions 1 and 2. The difference was statistically significant only 2 hours after dressing on the first treatment occasion. Thus, our study did not demonstrate a consistent and globally significant difference in nociception in patients treated with morphine. However, the relatively small number of patients included in our study and other methodological limitations makes it difficult for us to draw general conclusions regarding efficacy of topically applied morphine as an effective treatment for some painful ulcers. Further studies are warranted to evaluate the value of topically applied morphine in the treatment of patients with chronic painful leg ulcers.

Influence of CYP2D6 genotype on the disposition of the enantiomers of venlafaxine and its major metabolites in postmortem femoral blood

Venlafaxine (VEN) is an antidepressant drug mainly metabolized by the cytochrome P450 (CYP) enzyme CYP2D6 to the active metabolite O-desmethylvenlafaxine (ODV). VEN is also metabolized to N-desmetylvenlafaxine (NDV) via CYP3A4. ODV and NDV are further metabolized to N,O-didesmethylvenlafaxine (DDV). VEN is a racemic mixture of the S- and R-enantiomers and these have in vitro displayed different degrees of serotonin and noradrenaline reuptake inhibition. The aim of the study was to investigate if an enantioselective analysis of VEN and its metabolites, in combination with genotyping for CYP2D6, could assist in the interpretation of forensic toxicological results in cases with different causes of deaths. Concentrations of the enantiomers of VEN and metabolites were determined in femoral blood obtained from 56 autopsy cases with different causes of death. The drug analysis was done by liquid chromatography tandem mass spectrometry (LC/MS/MS) and the CYP2D6 genotyping by PCR and pyrosequencing. The mean (median) enantiomeric S/R ratios of VEN, ODV, NDV and DDV were 0.99 (0.91), 2.17 (0.93), 0.92 (0.86) and 1.08 (1.03), respectively. However, a substantial variation in the relationship between the S- and R-enantiomers of VEN and metabolites was evident (S/R ratios ranging from 0.23 to 17.6). In six cases, a low S/R VEN ratio (mean 0.5) was associated with a high S/R ODV ratio (mean 11.9). Genotyping showed that these individuals carried two inactive CYP2D6 genes indicating a poor metabolizer phenotype. From these data we conclude that enantioselective analysis of VEN and ODV can predict if a person is a poor metabolizer genotype/phenotype for CYP2D6. Knowledge of the relationship between the S- and R-enantiomers of this antidepressant drug and its active metabolite is also important since the enantiomers display different pharmacodynamic profiles.

Effects on enantiomeric drug disposition and open-field behavior after chronic treatment with venlafaxine in the P-glycoprotein knockout mice model

RATIONALE

P-glycoprotein (P-gp) plays an important role in the efflux of drugs from the brain back into the bloodstream and can influence the pharmacokinetics and pharmacodynamics of drug molecules. To our knowledge, no studies have reported pharmacodynamic effects of any antidepressant drug in the P-gp knockout mice model.

OBJECTIVE

The aim of this study was to investigate the enantiomeric venlafaxine and metabolite concentrations in serum and brain of abcb1ab⁻/⁻ mice compared to wild-type mice upon chronic dosing, and to assess the effect of venlafaxine treatment on open-field behavior.

METHODS

P-gp knockout and wild-type mice received two daily intraperitoneal injections of venlafaxine (10 mg/kg) over ten consecutive days. Locomotor and rearing activities were assessed on days 7 and 9. After 10 days, drug and metabolite concentrations in brain and serum were determined using an enantioselective LC/MS/MS method.

RESULTS

The brain concentrations of venlafaxine and its three demethylated metabolites were two to four times higher in abcb1ab⁻/⁻ mice compared to abcb1ab+/+ mice. The behavioral results indicated an impact on exploration-related behaviors in the open-field as center activity was increased, and rears were decreased by venlafaxine treatment.

CONCLUSION

Our results show that P-gp at the blood-brain barrier plays an important role in limiting brain entry of the enantiomers of venlafaxine and its metabolites after chronic dosing. Taken together, the present pharmacokinetic and pharmacodynamic findings offer the possibility that the expression of P-gp in patients may be a contributing factor for limited treatment response.

Antidepressant medication prevents suicide in depression

OBJECTIVE

Ecological studies have demonstrated a substantial decrease in suicide in parallel with an increasing use of antidepressants. To investigate on the individual level the hypothesis that antidepressant medication was a causal factor.

METHOD

Data on the toxicological detection of antidepressants in 18 922 suicides in Sweden 1992-2003 were linked to registers of psychiatric hospitalization as well as registers with sociodemographic data.

RESULTS

The probability for the toxicological detection of an antidepressant was lowest in the non-suicide controls, higher in suicides, and even higher in suicides that had been psychiatric in-patients but excluding those who had been in-patients for the treatment of depression.

CONCLUSION

The finding that in-patient care for depression did not increase the probability of the detection of antidepressants in suicides is difficult to explain other than by the assumption that a substantial number of depressed individuals were saved from suicide by postdischarge treatment with antidepressant medication.

Blood-brain barrier penetration of the enantiomers of venlafaxine and its metabolites in mice lacking P-glycoprotein

According to in vitro studies the enantiomers of venlafaxine display different degrees of serotonin and noradrenaline reuptake inhibition. Therefore, clarification of the enantiomeric drug distribution between serum and brain is highly warranted. To elucidate if P-glycoprotein (P-gp) in a stereoselective manner transports venlafaxine and its metabolites out of the brain we used abcb1ab double-knockout mice that do not express P-gp. A single dose of racemic venlafaxine (10 mg/kg bw) was intraperitoneally injected to knockout (-/-) and wildtype (+/+) mice. Serum and brain samples were collected 1, 3, 6 and 9 h following drug administration for analysis by LC/MS/MS. One to six hours post-dose, the brain concentrations of venlafaxine, O-desmethylvenlafaxine and N-desmethylvenlafaxine were 2-3, 2-6 and 3-12 times higher in abcb1ab (-/-) mice compared to abcb1ab (+/+) mice, respectively. No major differences in the serum and brain disposition of the S- and R-enantiomers of venlafaxine and its metabolites were found between the groups. We conclude that P-gp decreases the penetration of the S- and R-enantiomers of venlafaxine and its major metabolites into the brain. No evidence of a stereoselective P-gp mediated transport of these substances was observed.

Drug poisoning deaths in Sweden show a predominance of ethanol in mono-intoxications, adverse drug-alcohol interactions and poly-drug use

Over a 10-year period (1998-2007) all deaths in Sweden classified by forensic pathologists as fatal drug poisonings (N = 6894) were retrieved from a toxicology database (TOXBASE) belonging to the National Board of Forensic Medicine. The deaths were further classified as suicides N = 2288 (33%), undetermined N = 2260 (33%) and accidental N = 2346 (34%). The average age (± SD) of all victims was 49.1 ± 15.9 years and men 47.4 ± 15.6 years were 5-year younger than women 52.2 ± 15.8 years (p < 0.01). Most of the deceased (78%) were poly-drug users although a single drug (mono-intoxications) was found in 22% of all poisoning deaths (p < 0.001). The number of drugs in blood samples varied from 1 to 12 with a median of 3-4 per case. Mono-intoxication deaths were mostly ethanol-related (N = 976) and the mean and median blood-alcohol concentration (BAC) was 3.06 g/L and 3.10 g/L, respectively. The BAC decreased as the number of additional drugs in blood increased from 2.15 g/L with one drug to 1.25 g/L with 6 or more drugs. The mean (median) concentrations of non-alcohol drugs in mono-intoxication deaths were morphine (N = 93) 0.5mg/L (0.2mg/L), amphetamine (N = 39) 2.0mg/L (1.2mg/L), dextropropoxyphene (N = 33) 3.9 mg/L (2.9 mg/L), dihydro-propiomazine (N = 32) 1.6 mg/L (1.0mg/L) and 7-amino-flunitrazepam (N = 28), 0.4 mg/L (0.3mg/L). Elevated blood morphine in these poisoning deaths mostly reflected abuse of heroin as verified by finding 6-monoacetyl morphine (6-MAM) in the blood samples. When investigating drug poisoning deaths a comprehensive toxicological analysis is essential although the results do not reveal the extent of prior exposure to drugs or the development of pharmacological tolerance. The concentrations of drugs determined in post-mortem blood are one element in the case. The autopsy report, the police investigation, the findings at the scene and eye-witness statements should all be carefully considered when the cause and manner of death are determined.

Caffeine fatalities--do sales restrictions prevent intentional intoxications?

OBJECTIVE

Caffeine is widely available in beverages and in different over-the-counter products, including tablets containing 100 mg caffeine. Because intentional fatal intoxications with caffeine occur, the maximum quantity of caffeine tablets that can be bought over the counter in a single purchase was restricted from 250 to 30 in Sweden in the year 2004. The objective of this article was to study the effect of this decision on the number of fatal caffeine intoxications.

METHOD

In Sweden 95% of all cases undergoing forensic autopsy are screened for a number of drugs including caffeine. All cases during January 1993-September 2009 with a caffeine concentration above 80 microg/g blood were recorded.

RESULTS

During the study period toxicological investigations were performed in 83,580 forensic autopsies. Caffeine contributed to the fatal outcome in 20 cases (0.02%). Thirteen (65%) of these fatalities occurred before the introduction of the sales restriction. However, no fatal intoxications where caffeine contributed to the cause of death was recorded between May 2007 and September 2009.

CONCLUSION

Overdoses of tablets containing caffeine can be fatal, suicides as well as accidents occur. Restricting the maximum quantity of caffeine tablets available over the counter seemed to be effective in preventing suicides because of caffeine although some time elapsed until the effect was noted. Further monitoring is required to ensure that the observed lower caffeine mortality is a sustained effect.

Tramadol dependence: a survey of spontaneously reported cases in Sweden

BACKGROUND

Tramadol is a weak opioid analgesic, which is generally considered to be safe. However, conflicting data exist on the dependence potential of tramadol.

OBJECTIVE

The aim of this study was to investigate occurrence of tramadol dependence and associated risk factors using spontaneously reported adverse drug reactions.

METHODS

The Swedish database for spontaneously reported adverse drug reactions, Swedish Drug Information System (SweDIS), was searched for reports on tramadol dependence from 1 January 1995 until 31 December 2006. Selection was conducted based on the DSM-IV definition of dependence. Available information was scrutinised and registered and then presented descriptively.

RESULTS

A total of 104 reports of tramadol dependence were identified, of which 60 (58%) concerned women. The median age (range) was 45 (15-84) years. Information on a history of substance abuse was present in 31 patients (30%) and 41 patients (39%) had a documented past or current use of a drug of abuse. Prescribed doses of tramadol ranged between 50-800 mg/day, and ingested doses between 50-4000 mg/day. Time of onset ranged from some weeks up to 4 years. In 72 (69%) cases the reaction was classified as serious, mainly due to hospitalisations for detoxification or discontinuation of tramadol.

CONCLUSIONS

There is an occurrence of tramadol dependence in association with analgesic treatment within the recommended dose range. In susceptible patients a severe and serious dependence syndrome may develop. A history of abuse or use of a drug of abuse seems to be an important risk factor.

High frequency of occurrence of CYP2D6 gene duplication/multiduplication indicating ultrarapid metabolism among suicide cases

In Sweden, about 550 individuals die every year of drug intoxication. Many of these drugs are metabolized by CYP enzymes such as CYP2D6 and CYP2C19. A lack of these enzymes, resulting in poor metabolism, can lead to adverse reactions and even to fatality. On the other hand, an ultrarapid metabolism can lead to insufficient drug plasma concentration, resulting in failure of treatment, or it can lead to high concentrations of active/toxic metabolites. The aim of this project was to study the genetic profile of individuals with regard to the presence of CYP2D6 and CYP2C19 genes, in cases of fatal intoxication (242), suicide (intoxications excluded) (262), and natural death (212). PCR, followed by pyrosequencing, was used for all the analyses. We found that, among those who died of suicide (suicide cases), there was a higher number carrying more than two active CYP2D6 genes (corresponding to the phenotype of ultrarapid metabolizer) as compared with those who died of natural causes (natural-death cases) (P = 0.007).

Decrease in suicide among the individuals treated with antidepressants: a controlled study of antidepressants in suicide, Sweden 1995-2005

OBJECTIVE

Ecological studies have demonstrated a substantial decrease in suicide in parallel with an increase in the use of antidepressants. Causality cannot, however, be inferred from such studies. The aim of this study was to test on the individual level the hypothesis that treatment with antidepressant medication has been a substantially contributing cause of the decrease in suicide.

METHOD

Time trends in the detection of antidepressants and five 'control medications' in the forensic toxicological screening of 16 937 suicides and 33 426 controls in Sweden 1995-2005.

RESULTS

The expected number of antidepressant-positive suicides in 2005 was 409 if the hypothesis was true and 603 if it was false. The observed number in 2005 was 420. The control medications were detected to the extent that was expected if not preventing suicide.

CONCLUSION

The observed trend in the number of suicides with antidepressants was well predicted by the hypothesis that the increased use of antidepressants has been a substantially contributing cause of the decrease in suicide.