Citalopram is marketed as a racemate (50:50) mixture of the S(+)-enantiomer and R(-)-enantiomer and the active S(+)-enantiomer (escitalopram) that possess inhibitory effects. Citalopram was introduced in Sweden in 1992 and is the most frequently used antidepressant to date in Sweden. In 2002, escitalopram was introduced onto the Swedish market for treatment of depression and anxiety disorders. The main objective of this study was to investigate S(+)-citalopram [i.e., the racemic drug (citalopram) or the enantiomer (escitalopram)] present in forensic autopsy cases positive for the presence of citalopram in routine screening using a non-enantioselective bioanalytical method. Fifty out of the 270 samples found positive by gas chromatography-nitrogen-phosphorus detection were further analyzed using enantioselective high-performance liquid chromatography. The 50 cases were genotyped for CYP2D6 and CYP2C19, as these isoenzymes are implicated in the metabolism of citalopram and escitalopram. In samples positive for racemic citalopram using the screening method for forensic autopsy cases, up to 20% would have been misinterpreted in the absence of an enantioselective method. An enantioselective method is thus necessary for correct interpretation of autopsy cases, after the enantiomer has been introduced onto the market. The percentage of poor metabolizers was 6% for CYP2D6 and 8% for CYP2C19.

A compilation of postmortem femoral blood concentrations of drugs is presented. The samples are collected from cases in which the cause of death was: A) certified intoxication by one substance alone, B) certified intoxication by more than one substance and/or alcohol, and C) certified other cause of death without incapacitation due to drugs. The concentrations were compared with blood concentrations detected in suspected drugged drivers (D), and with previously published fatal and therapeutic concentrations. The special features of this compilation are: 1) exclusively femoral blood concentrations are quoted, 2) all analyses are based on samples handled according to a standardized, quality-controlled procedure, 3) two control groups are included, and 4) one-substance-only intoxications are separated from other intoxications. The material is based on a selection of 15,800 samples sent to the Department of Forensic Chemistry in Linkoping, Sweden, during 1992 to 1995 from the six forensic pathology units in Sweden, and the list includes 83 drugs. The compilation includes drugs, where previously published data are scarce. Furthermore, the data gathered from cases with other cause of death than intoxication (group C) constitute a new kind of reference information, which probably offers a better estimate of obviously non fatal levels in postmortem blood than any compilation of therapeutic concentrations in living subjects. The possible factors influencing postmortem drug concentrations are discussed.

Citalopram, a selective serotonin reuptake inhibitor, is one of the most commonly found drugs in Swedish forensic autopsy cases. Citalopram is a racemic drug with 50:50 of the S- and R- enantiomers. Enantioselective analysis of citalopram and its metabolites desmethylcitalopram and didesmethylcitalopram were performed in femoral blood from 53 autopsy cases by a chiral high-performance liquid chromatography (HPLC) method. The mean (± standard deviation) S/R ratio for citalopram was 0.67 ± 0.25 and for desmethylcitalopram, 0.68 ± 0.20. We found increasing S/R ratios with increasing concentrations of citalopram. We also found that high citalopram S/R ratios were associated with a high parent drug-to-metabolite ratio and may be an indicator of recent intake. Citalopram is metabolized by cytochrome P450 (CYP) 3A4, 2C19, and 2D6. Genotyping for the polymorphic CYP2C19 and CYP2D6 revealed no poor metabolizers regarding CYP2C19 and only 2 (3.8%) poor metabolizers regarding CYP2D6. The presence of drugs metabolized by and/or inhibiting these enzymes in several of the cases suggests that such pharmacokinetic interactions are a more important (practical) problem than metabolic deficiency. Enantioselective analysis of citalopram and its metabolites can provide additional information when interpreting forensic toxicology results and might be a necessity in the future.

Objective: Multiple drug intake is a problem in tbe clinical setting with potential to adverse drug reactions and certainly a problem in interpretation of forensic toxicology results. The aims of this investigation were to study the incidence of concomitant drugs in autopsy cases where citalopram or zopiclone were detected in femoral blood and to evaluate the potential of drug interactions.

Methods: All medico-legal autopsy cases in Sweden during 1992 to 2003 where citalopram or zopiclone were detected in femoral blood at the toxicological analyses were selected. The number and occurrences of concomitant drugs were recorded together with the concentrations as well as the cause of death.

Results: In the 2405 cases with citalopram, 123 different drugs, metabolites excluded, were detected 4679 times giving an average of 1.9 concomitant drugs and 1099 different dmg combinations were identified. The corresponding figures for the cases with zopiclone were 1557 cases, 118 different drugs detected 3984 times giving an average of 2.6 concomitant drugs and 977 different combinations. We found a strong positive correlation between the number of drugs detected and the frequency of cases judged to be intoxication.

Conclusions: Pharmacokinetic and pharmacodynamic interactions are a potential problem when interpreting forensic toxicological results and the conclusions about the cause and manner of death in the single case must be based on all available information from the investigation and tbe autopsy and on tbe knowledge of tbe pharmacology of included drugs. A better control of prescriptions of what different drugs an individual is given together with a comprehensive therapy control may reduce the risks of adverse drug reactions and unintended or accidental intoxications.

The stability of 46 drugs in postmortem femoral blood stored for one year at -20°C was investigated. The drugs included benzodiazepines, antidepressants, analgetics and hypnotics. For seven drugs we found a significant change in the concentration between the first and second analysis. Five substances; ethanol, desmethylmianserin, 7-amino-nitrazepam, THC and zopiclone showed a decrease in the concentration whereas the concentrations of two substances; ketobemidone and thioridazine increased. However, the changes observed were not of such an order that it would affect the interpretation in normal forensic casework. We also investigated the possible influence of potassium fluoride on the concentrations of the 46 drugs in vitreous humor after storage for one year. For two substances, ethanol and zopiclone, there were significantly lower concentrations in the samples without potassium fluoride. Furthermore, we also studied the correlation between the concentrations in femoral blood and vitreous humor. For 23 substances there was a significant difference between the concentrations in the vitreous humor and femoral blood. Significant correlations between the concentrations in these two specimens were found for 23 substances, indicating that vitreous humor can be an alternative specimen when blood samples are not available, provided that such correlation exists for the particular substance. Statistical analysis also revealed a correlation between the degree of protein binding of the different drugs and percentage of vitreous/femoral blood concentrations.

Aims To investigate whether the relative amounts of fat, carbohydrate (CHO), or protein in a meal influence the pharmacokinetics of a small dose of ethanol.

Methods Nine healthy men received ethanol (0.30 g kg⁻¹ body weight) on five occasions in a randomized cross-over fashion. On three occasions the dose of ethanol was consumed within 15 min of eating a standardized breakfast of similar volume and calorific value but containing different amounts of fat, CHO, and protein. On two other occasions the same dose of ethanol was ingested on an empty stomach (overnight fast) or administered by intravenous (i.v.) infusion over 30 min.

Results The blood-ethanol profiles showed large inter and intraindividual variations, especially when ethanol was ingested after eating food. The peak blood-alcohol concentrations (BAC) were 16.6±4.0, 17.7±7.1, and 13.3±4.0 mg dl⁻¹ (mean±s.d.) after fat, CHO, and protein-rich meals and 30.8±4.3 and 54.3±6.4 mg dl⁻¹ after fasting and i.v. infusion, respectively. The corresponding areas under the concentration-time profiles (AUC) were 1767±549, 1619±760, 1270±406 mg dl⁻¹ min after fat, CHO, and protein-rich meals compared with 3210±527 and 4786±446 mg dl⁻¹  min after fasting and i.v. infusion, respectively. The time required to eliminate ethanol from the blood was shortened by 1–2 h in the fed-state.

Conclusions Drinking ethanol after eating a meal, regardless of the nutritional composition, decreases the systemic availability of ethanol. Because gastric emptying is slow and more prolonged with food in the stomach, the delivery of ethanol to the duodenum and the liver will be highly variable as will the hepatic clearance of ethanol. Provided that portal venous BAC remains fairly low and ethanol metabolizing enzymes are not fully saturated then part of the dose of ethanol can be cleared by hepatic first-pass metabolism (FPM), as one consequence of Michaelis-Menten elimination kinetics.

Gastroesophageal reflux disease (GERD) is widespread in the population among all age groups and in both sexes. The reliability of breath alcohol analysis in subjects suffering from GERD is unknown. We investigated the relationship between breath-alcohol concentration (BrAC) and blood-alcohol concentration (BAC) in 5 male and 5 female subjects all suffering from severe gastroesophageal reflux disease and scheduled for antireflux surgery. Each subject served in two experiments in random order about 1-2 weeks apart. Both times they drank the same dose of ethanol (~0.3 g/kg) as either beer, white wine, or vodka mixed with orange juice before venous blood and end-expired breath samples were obtained at 5-10 min intervals for 4 h. Ah attempt was made to provoke gastroesophageal reflux in one of the drinking experiments by applying an abdominal compression belt, Blood-ethanol concentration was determined by headspace gas chromatography and breath-ethanol was measured with an electrochemical instrument (Alcolmeter SD-400) of a quantitative infrared analyzer (Data-Master). During the absorption of alcohol, which occurred during the first 90 min after the start of drinking, BrAC (mg/210 L) tended to be the same of higher than venous BAC (mg/dL). In the post-peak phase, the BAC al ways exceeded BrAC. Four of the 10 subjects definitely experienced gastric reflux during the study although this did not result in widely deviant BrAC readings compared with BAC when sampling occurred at 5- min intervals. We conclude that the risk of alcohol erupting from the stomach into the mouth owing to gastric reflux and falsely increasing the result of an evidential breath-alcohol test is highly improbable.

Aims To examine the influence of cisapride on the pharmacokinetics of ethanol and the impact of gastric emptying monitored by the paracetamol absorption test.

Methods Ten healthy male volunteers took part in a cross-over design experiment. They drank a moderate dose of ethanol 0.30 g kg⁻¹ body weight exactly 1 h after eating breakfast either without any prior drug treatment or after taking cisapride (10 mg three times daily) for 4 consecutive days. In a separate study, the same dose of ethanol was ingested on an empty stomach (overnight fast). Paracetamol (1.5 g) was administered before consumption of ethanol to monitor gastric emptying. Venous blood was obtained at 5–10 min intervals for determination of ethanol by headspace gas chromatography and paracetamol was analysed in serum by high performance liquid chromatography (h.p.l.c.).

Results The maximum blood-ethanol concentration (C_max ) increased from 3.8±1.7 to 5.6±2.3 mmol l⁻¹ (±s.d.) after treatment with cisapride (95% confidence interval CI on mean difference 0.28–3.28 mmol l⁻¹ ). The area under the blood-ethanol curve (AUC) increased from 6.3±3.5 to 7.9±2.6 mmol l⁻¹ h after cisapride (95% CI −0.74–3.9 mmol l⁻¹ h). The mean blood ethanol curves in the cisapride and no-drug sessions converged at ≈2 h after the start of drinking. Both C_max and AUC were highest when the ethanol was ingested on an empty stomach (C_max 9.5±1.7 mmol l⁻¹ and AUC 14.6±1.9 mmol l⁻¹ h), compared with drinking 1 h after a meal and regardless of pretreatment with cisapride.

Conclusions A small but statistically significant increase in C_max occurred after treatment with cisapride owing to faster gastric emptying rate as shown by the paracetamol absorption test. However, the rate of absorption of ethanol, as reflected in C_max and AUC, was greatest after drinking the alcohol on an empty stomach. The cisapride–ethanol interaction probably lacks any clinical or forensic significance.

Objective: To determine if treatment with low-dose aspirin (ASA) influences the bioavailability of orally administered alcohol and to assess whether this is caused by altered gastric emptying as measured by the paracetamol absorption test.

Methods: In a single-center controlled crossover trial, ten healthy male medical students, aged 20–27 years, participated in two experiments in random order. Both times they took paracetamol (1.5 g together with a standardized breakfast) and drank ethanol (0.3 g/kg) 1 h after eating breakfast. On one drinking occasion, no previous medication was given. The other alcohol session was performed after the subjects had taken 75 mg ASA once daily for 7 days. On both occasions, venous blood samples were obtained at exactly timed intervals for a period of 3.5 h.

Results: The blood-ethanol profiles showed large interindividual variations for both experiments. After treatment with ASA, the maximum blood-ethanol concentration was distinctly lower in seven subjects, almost unchanged in two subjects and increased in one subject. Overall, a statistically significant decrease in the peak blood-ethanol concentration was observed. The time required to reach peak blood-ethanol levels was somewhat longer after treatment with ASA. Although the areas under the concentration–time profiles were smaller after ASA treatment, these differences were not statistically significant. The concentrations of paracetamol in plasma were lower when ethanol was ingested after treatment with ASA and the areas under the concentration–time curves (0–170 min) were smaller.

Conclusions: Intake of low-dose ASA (75 mg daily) tends to delay the absorption of a moderate dose of ethanol, which results in lower peak blood-ethanol concentrations and smaller areas under the concentration–time curves. The underlying mechanism seems to be delayed gastric emptying as indicated by the paracetamol absorption test.

Background: Gastric alcohol dehydrogenase may contribute to the metabolism of orally ingested ethanol and decrease the bioavailability of the drug. The aims of this study were to assess the impact of Helicobacter pylori infection and its eradication on gastric alcohol dehydrogenase activity and to relate the findings to gastric histology. Furthermore, the role of age- and sex-related differences in gastric alcohol dehydrogenase activity were studied.

Methods: A total of 76 subjects (39 women and 37 men) underwent upper gastrointestinal endoscopy, and biopsies were obtained from the corpus and antrum. The specimens were used for determining gastric alcohol dehydrogenase activity, histological examination, and urease testing. Subjects with H. pylori infection (n= 36) received medication to eradicate the infection, and repeat biopsies were taken 2 and 12 months later.

Results: No significant difference in gastric alcohol dehydrogenase activity was found between men and women (p > 0.05). Gastric alcohol dehydrogenase activity did not differ significantly between the subjects older than 50 years (n= 39) and those 50 years or younger (n= 37). In subjects with H. pylori infection, gastric alcohol dehydrogenase activity was significantly reduced in the antrum (p < 0.05). After eradication of H. pylori, alcohol dehydrogenase activity in the antrum increased significantly within 2 months (p < 0.01). Antral biopsies with the most pronounced inflammation and histological changes had significantly decreased alcohol dehydrogenase activity (p < 0.05). In contrast, no significant differences were found in corpus.

Conclusions: H. pylori infection is associated with decreased antral alcohol dehydrogenase activity, which seems to be related to the severity of the inflammatory changes in the mucosa. Eradication of H. pylori normalizes antral alcohol dehydrogenase activity within 2 months.

Hair and plasma from patients on long-term selegiline medication were analyzed to evaluate the relationships between plasma and hair melanin concentrations and the incorporation of the selegiline metabolites methamphetamine and amphetamine in hair, and to evaluate hair analyses for determining compliance in medication. Analyses were performed on both the whole hairs, as well as pigmented and non-pigmented hairs from gray-haired patients. Melanin was quantitated by spectrophotometry, and metabolites were quantitated by gas chromatography-mass spectrometry. Concentrations in pigmented and non-pigmented hairs differed significantly for both methamphetamine (p < 0.01) and amphetamine (p < 0.02), with mean concentration ratios being 3.69 ± 1.88 and 2.95 ± 1.16 for methamphetamine and amphetamine, respectively. Segmental analysis indicated that some patients had not been compliant with medication. We concluded that the incorporation of methamphetamine and amphetamine into hair of single individuals shows a preference for pigmented hairs over white hairs and that segmental analysis of hair may he useful when measuring compliance with medication.

We have previously shown that melanin in human hair has a great impact on the incorporation of codeine into hair. The present study on 10 subjects was performed to investigate whether or not these findings could also be extrapolated to other therapeutic drugs. We chose selegiline because it metabolizes to two commonly abused central stimulants, methamphetamine and amphetamine. The results would therefore also be of interest when studying the intake of such drugs and their incorporation into human hair. Selegiline and metabolites were determined by gas chromatography-mass spectrometry, total melanin by spectrophotometry, and pyrroletricarboxylic acid by high-performance liquid chromatography with ultraviolet detection. Our results show strong positive exponential relationships (y = e^x) between melanin and the metabolites, which for methamphetamine improved by normalizing for plasma area under the curve. We conclude that the major metabolites of selegiline can be detected in hair up to four weeks after a single oral dose and that the incorporation closely relates to the melanin contents.

Background: Analysis of drugs in hair has been used on a qualitative basis to estimate earlier exposure to drugs. Clinical applications are rare because of the lack of dose–response relationships in the studies performed to date, and questions remain regarding the mechanisms of drug incorporation into hair. Several human studies have shown differences in drug accumulation between pigmented and nonpigmented hair. However, the melanin concentration in hair was not determined and correlated to the amount of drug incorporated.

Methods: Nine human subjects were given codeine as a single oral dose, and plasma codeine concentrations were determined for 24 h, using gas chromatography–mass spectrometry. Hair samples were obtained weekly for a month. Total melanin, eumelanin, and codeine were measured quantitatively in hair samples by spectrophotometry, HPLC, and gas chromatography–mass spectrometry, respectively.

Results: There was an exponential relationship between codeine and melanin concentrations in hair, (r² = 0.95 with total melanin and r² = 0.83 with eumelanin). After normalizing the results by the area under the curve for codeine in plasma, we obtained r² = 0.86 for codeine vs total melanin and r² = 0.90 vs eumelanin.

Conclusions: Our results stress the importance of melanin determination when measuring drugs in hair. We postulate that analysis of drug concentration in hair may be worthwhile in the monitoring of drug compliance if the results are normalized for melanin content.

The purpose of the present study was to investigate the occurrence in hair, of some drugs of abuse in deaths caused by heroin overdose, in comparison to findings in blood. Blood, urine and hair samples were obtained during routine post mortem examinations. Samples were analysed for amphetamines, opiates, and cocaine. Immunometric drug screening was performed in urine and positive results confirmed with gas chromatography–mass spectrometry (GC–MS) of blood samples. All hair samples were analyzed with GC–MS. Hair samples were either incubated with methanol for determination of opiates and cocaine, or dissolved in sodium hydroxide for determination of amphetamines. All 19 blood samples were positive for morphine (0.04–0.4 μg g⁻¹) and ten were also positive for 6-acetylmorphine (0.003–0.02 μg g⁻¹). Thirteen of the hair samples were positive for 6-acetylmorphine and seven of which were positive also for morphine. Concentrations ranged from 0.3–7.4 and 0.3–1.3 (ng mg⁻), respectively. Amphetamine was found in three blood samples (0.04–1.2 μg g⁻¹) and in eleven hair samples (0.4–18.3 ng mg⁻). Cocaine was determined in one blood sample (0.03 μg g⁻¹) and two hair samples (0.7–6.5 ng mg⁻). Out of the nineteen cases studied, eight showed chronic multi drug use on the basis of the results of hair analysis. In six subjects no opiates could be detected in hair, suggesting; “first” or occasional intake of heroin, which could be a contributing factor to the overdose death, because of lack of tolerance. We conclude that analysis of hair can be a useful complement to analysis of more conventional autopsy material, especially when investigating overdose deaths and previous histories of drug use and abuse.

The aim of this study was to develop a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the analysis of benzodiazepines in human hair. The method was tested by analyzing hair samples from forensic and clinical psychiatric patients where benzodiazepines had been prescribed during hospitalization and after care. Hair samples were obtained at discharge from the clinic and then after six months. Two-centimeter segments of the hair samples (10–30 mg) were washed once with isopropanol, three times with phosphate buffer, and again with isopropanol, dried, weighed, and digested with proteinase K before solid-phase extraction with BondElut Certify columns. Diazepam, nordiazepam, oxazepam, alprazolam, OH-alprazolam, nitrazepam, 7-aminonitrazepam, flunitrazepam, 7-aminoflunitrazepam, clonazepam, and 7-aminoclonazepam were quantitated in MRM mode using one transition for each analyte and deuterated internal standard. The calibration range was 0.125–5 ng/mg for diazepam, nordiazepam, and oxazepam and 0.025–1.0 ng/mg for the other compounds. In the hair samples analyzed, diazepam, flunitrazepam, nitrazepam, and clonazepam was detected together with their metabolites. Alprazolam was not detected in any sample. Segmental hair analysis revealed differences in drug deposition in hair before and after release from psychiatric treatment. Both increases and decreases of hair drug concentrations were seen after release even though the prescribed dose was the same. This was taken as an indication of noncompliance during the after-care period. We conclude that the extraction and LC-MS-MS procedures were adequate to detect benzodiazepines in hair and that the results indicated that segmental hair analysis might provide retrospective information about medication intake.

Aims: To investigate the effect of an amino acid mixture given intravenously (i.v.) on the rate of ethanol elimination from blood compared with equicaloric glucose and Ringer's acetate as control treatments.

Methods: In a randomized cross-over study, six healthy men (mean age 23 years) fasted overnight before receiving either Ringer's acetate, glucose or the amino acid mixture (Vamin 18 g N/l^®) by constant rate i.v. infusion over 4.5 h. Ethanol (0.4 g/kg) was given by an i.v. infusion lasting 60 min during the time each of the treatments was administered. At various times post-infusion, blood samples were taken for determination of ethanol by headspace gas chromatography. Blood glucose and heart rate were monitored at regular intervals. Concentration–time profiles of ethanol were plotted for each subject and the rate of ethanol disappearance from blood as well as other pharmacokinetic parameters were compared by repeated measures analysis of variance.

Results: The rate of ethanol elimination from blood was increased significantly (P < 0.001) after treatment with amino acids (mean ± SD, 0.174 ± 0.011 g/l/h) compared with equicaloric glucose (0.121 ± 0.016 g/l/h) or Ringer's acetate (0.110 ± 0.013 g/l/h). Heart rate was also slightly higher during infusion of the amino acid mixture (P < 0.05).

Conclusions: When the rate of ethanol elimination from blood is relatively slow, such as after an overnight fast, it can be increased by ∼60% after treatment with i.v. amino acids. The efficacy of amino acid treatment was not related to the supply of calories because glucose was no more effective than Ringer's acetate. We suggest that amino acids might increase hepatic oxygen consumption, resulting in a more effective conversion of NADH to NAD⁺ in mitochondria. An important feature of the experimental design was ensuring hepatic availability of amino acids during much of the time that ethanol was being metabolized.

Amphetamine has been used in Attention Deficit Hyperactivity Disorder (ADHD), narcolepsy, and as an appetite suppressant either as the racemate or in different proportions of its enantiomers. In Linköping, Sweden, the Department for Drug Dependence has successfully treated drug abusers also diagnosed with Adult ADHD with Metamina^® [S-(+)-amphetamine]. Because of the high risk of relapse into drug abuse, a strategy involving the analysis of amphetamine enantiomers in blood and hair was investigated for the assessment of compliance as well as abstinence from street amphetamine. Four patients were included: one patient was treated with racemic amphetamine, and three with Metamina. Blood and hair samples were obtained as a part of the treatment. A basic extraction of the analytes into iso-octane was used. Hair was dissolved in sodium hydroxide before extraction. Chiral derivatization was performed by reaction with S-(−)-N-(trifluoroacetyl)prolyl chloride. Quantitation of R-(−)- and S-(+)-amphetamine was performed by gas chromatography-mass spectrometry in selected ion monitoring. Both blood and hair sample results showed good compliance for patients 1 and 2. Patient 3 and 4 showed different percentages of S-(+)-amphetamine in hair together with varying total concentrations, suggesting intake of additional racemic illicit amphetamine. During treatment, these patients also showed other signs of noncompliance, and one was temporarily withdrawn from treatment. We conclude that the method is suitable to detect therapeutic concentrations of R-(−)- and S-(+)-amphetamine in both blood and hair and that hair reveals noncompliance not shown by concentrations or enantiomer ratios in blood.

In both clinical and forensic toxicology, the analysis of hair for drugs is an important tool to determine drug use in the past or to verify abstinence from illegal drugs during extended periods. Melanin is proposed as one of the factors that influences drug incorporation to hair and we have characterized the binding of the drug flunitrazepam to melanin in vitro. The drug was ³H labeled and melanin granules from cuttlefish, Sepia officinalis, were used according to the suggested standard for melanin studies. We observed a rapid Langmuir-like binding followed by a slower diffusion-limited binding that may be interpreted as an initial surface binding followed by deeper bulk binding. From three concentrations of melanin, with a 60-min incubation time, a mean saturation value of 180 ± 20 pmol/mg was calculated. The binding of a group of benzodiazepines and tranquilizers was compared to the binding of [³H]flunitrazepam by means of displacement experiments. These drugs showed binding characteristics similar to [³H]flunitrazepam except phenobarbital, which had a lower affinity to melanin. The method presented in this study allowed measurements with low melanin and drug concentrations and it has the strength of directly measuring the amount of drug bound to melanin, in contrast to previous indirect methods.

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. Copyright (c) 2009 John Wiley & Sons, Ltd.