Relationship between unbound plasma concentrations and various psychomotor and subjective effects after intakes of diazepam and flunitrazepam

Unbound plasma concentrations of diazepam and flunitrazepam were related to psychomotor and subjective effects of the two drugs. The interindividual variability in plasma protein binding of both diazepam (98.5 +/- 0.14%) and flunitrazepam (84.5 +/- 1.2%) was relatively small, and high correlations were therefore observed between the individual unbound and total drug plasma concentrations after a particular dose. However, poor correlations were seen between individual unbound drug plasma concentrations and psychomotor or subjective effects. This observation indicates that factors other than individual variability in drug plasma concentration, account for the pronounced individual differences in, for example, psychomotor impairment frequently observed after intake of benzodiazepines. Furthermore, based on a linear relationship between unbound drug plasma concentrations and increase in either complex choice or simple reaction time, the potency of flunitrazepam was calculated to be about seven times higher than the potency of diazepam. This is approximately two times higher than expected from the reported in vitro affinity of the two drugs for the benzodiazepine receptor. This finding may indicate that flunitrazepam may have a higher apparent in vivo intrinsic efficacy than diazepam when assessed by psychomotor impairment.

Development of acute tolerance after oral doses of diazepam and flunitrazepam

Flunitrazepam (1 and 2 mg), diazepam (10 and 20 mg) or placebo was administered to healthy, male volunteers, and the time course of psychomotor impairment, as indicated by simple and complex choice reaction time and movement time, was studied during a period of 6 h after drug intake. To examine whether acute tolerance developed, the observed performance during decreasing drug plasma concentration was compared to the predicted performance based on kinetic-dynamic modelling of the observed performance during the first 1.5 h after intake when the drug plasma concentrations were increasing or at peak level. Placebo corrections of the test scores were accomplished to adjust for diurnal variation and the possible influence of learning during the test day. After the flunitrazepam treatments, the predictions overestimated the actual performance significantly with respect to simple and choice reaction time at the 6-h session after intake. After the diazepam treatments, however, no significant deviation was detected between predicted and observed performance. The results indicate that acute tolerance develops with respect to impairment of attention demanding performance after medium to large doses of flunitrazepam, and that tolerance is expressed after approximately 4-6 h following intake.

Amnesic effects and subjective ratings during repeated dosing of flunitrazepam to healthy volunteers

Flunitrazepam (1 mg) or placebo was administered once daily over a treatment period of 8 days to healthy, male volunteers to study the time course of the effects on memory functions and on subjective ratings of alertness and tension. The plasma level of flunitrazepam increased by approximately 40% (P < 0.05) during the treatment period. The mean pre-dose level of flunitrazepam on day 4 and day 8 was approximately 0.005 microM, and no residual effects on memory functions were observed. Intake of flunitrazepam decreased the number of freely recalled words by about 85% (P < 0.05) and significantly affected the subjects' rating of attention when tested during the first few hours after drug intake on day 1 of treatment. However, no significant effect on the subjects' rating of relaxation was observed. When tested similarly after 8 days treatment, flunitrazepam significantly affected the subjects' rating of relaxation (P < 0.01). Furthermore, no tolerance developed for the effect of flunitrazepam on free recall (P > 0.3) and the subjects' rating of attention (P > 0.7), and these effects had nearly equal time courses during the treatment period. This may indicate that the amnesic effect of benzodiazepines is at least partially mediated through the effects on attention or general arousal. Two of the subjects in the active drug group reported adverse reactions or incidents of discomfort during the 1st week following the treatment period, whereas none in the placebo group reported such reactions.

Different biotransformation of morphine in isolated liver cells from guinea pig and rat

The biotransformation of morphine was characterized in freshly isolated parenchymal and non-parenchymal liver cells from rats and guinea pigs in suspension culture to establish an in vitro model for morphine metabolism. Liver cells were prepared by a collagenase perfusion technique, and separated by differential centrifugation. Morphine metabolism was investigated at different concentrations (1, 5, 100 and 200 microM). Samples were taken repeatedly during 2-4 hr of incubation, and subsequently analysed on a HPLC system employing both UV and electrochemical detection. In suspensions of hepatocytes from both animal species morphine-3-glucuronide (M3G) was the major metabolite of morphine, and was formed at comparable rates at all concentrations examined. Guinea pig hepatocytes in addition produced considerable quantities of morphine-6-glucuronide (M6G), whereas this metabolite was detected only intracellularly in minor quantities in rat hepatocytes. The ratio between the two morphine glucuronides (M3G/M6G) in suspensions of guinea pig hepatocytes was approximately 4:1. N-Demethylation of morphine was more pronounced per mg cell protein in rat hepatocytes compared to guinea pig cells. Metabolic activity towards morphine was not detected in non-parenchymal cells of the two species. The morphine glucuronidation pattern found in guinea pig hepatocytes resembles to a greater extent than that found in rat hepatocytes the pattern found in in vivo studies of humans. It was concluded that isolated guinea pig parenchymal cells appeared to be a promising in vitro system for studies of morphine glucuronidation, and to observe metabolism in general.

Incidence of alcohol and drugs in fatally injured car drivers in Norway

Blood samples from 159 fatally injured drivers from 1989 and 1990, corresponding to 57% of all fatally injured drivers in Norway during this period, were analysed for alcohol and psychoactive drugs. Alcohol was found in 28.3% of the drivers, 27.0% above the legal limit of 0.05%. Drugs were found in 16.4% of the drivers; benzodiazepines and tetrahydrocannabinol were the drugs most frequently found. Among 79 drivers fatally injured in single-vehicle accidents, 41.8% were positive for alcohol and 21.5% were positive for drugs.

Ethylmorphine metabolism in isolated rat hepatocytes

The metabolism of ethylmorphine has been studied in suspensions of isolated rat hepatocytes. Early during incubation, the two major metabolic intermediates detected were morphine and norethylmorphine following N- and O-dealkylation of ethylmorphine, respectively. During subsequent incubation the concentration of the second metabolic intermediate, normorphine increased, before the concentration peaked at approximately 20 microM (100 microM ethylmorphine). Both morphine and normorphine were glucuronidated to form morphine-3-glucuronide and normorphine-3-glucuronide, respectively, which appeared to be the major metabolic end products. The percentage of ethylmorphine metabolized to morphine-3-glucuronide was found to be dependent on the initial concentration of ethylmorphine. With increasing initial ethylmorphine concentration the relative formation of morphine-3-glucuronide was reduced (29 +/- 10% at 5 microM, 18 +/- 5% at 20 microM, and 15 +/- 4% at 100 microM mean +/- S.D., n = 10). The concentrations of ethylmorphine and its metabolites were found to be higher in liver cells than in medium. Thus the ratios between the intra-/extra-cellular concentrations of ethylmorphine increased somewhat from an initial value of 4 during the period for which ethylmorphine could be detected intracellularly. The drug metabolites all exhibited ratios above 10 for the initial 100 min. of incubation. With time these ratios showed a decline, but even for prolonged incubation the ratios were 5 or higher for the end products. Thus considerable drug concentration gradients existed across the cell membrane of isolated rat hepatocytes.

An animal model of postmortem amitriptyline redistribution

An experimental rat model was developed to study postmortem changes of drug concentration after an acute overdose. Overnight fasted rats were fed 75 mg of amitriptyline (AMI). Two h after dosing, the rats were anaesthetized and blood samples were drawn from the femoral vein (peripheral blood--PB) and the heart (HB). The rats were sacrificed by CO2 and left at room temperature for either 0.1, 0.5, 1, 2, 5, 10, 24, 48, or 96 hours, when samples of heart blood, blood from the inferior vena cava (PB) and tissue samples from different liver lobes, heart, lungs, kidney, thigh muscle, and brain were taken. Samples were analyzed by high performance liquid chromatography. The AMI concentration in HB increased fairly rapidly within the first 2 h postmortem and from then the average ratio was 6.4 +/- 0.8 (mean +/- sem) (n = 31). In PB, the post/antemortem AMI concentration ratio followed an approximately exponential rise; at 2 h postmortem the ratio was 1.6 +/- 0.3 (n = 5), and at 96 h 55.1 +/- 23.8 (n = 4). For the main metabolite nortriptyline (NOR), the concentration changes followed the same pattern, but to a lesser extent. Among the tissues, the liver lobes had high, but variable drug concentrations; lobes lying closest to the stomach had the highest drug concentrations. The drug concentration in the lungs declined significantly. This animal model demonstrates postmortem drug concentration changes similar to those described in humans. Probable mechanisms include drug diffusion from the stomach and GI tract to the surrounding tissues and blood; and postmortem drug release from the lungs and possibly other drug-rich tissues into the blood.

Depot preparations of disulfiram: experimental and clinical results

Patient compliance with disulfiram is a troublesome clinical problem. Several strategies have been proposed as a solution to the problem, including subcutaneous implantation of disulfiram. However, well controlled studies of alcoholics and healthy volunteers have failed to discover a pharmacological effect of implanted disulfiram. A major reason for this failure appears to be poor absorption from an inadequate dose. Assessment of new sustained release formulation of depot disulfiram has been found to provoke a mild disulfiram-ethanol reaction (DER). Only a more severe DER would be expected to deter further drinking. If problems with absorption and appropriate dosing of disulfiram can be resolved or a depot preparation of the active metabolite of disulfiram can be prepared, implants might find continued clinical use.

Co-variation between biological markers and self-reported alcohol consumption. A two-year study of the relationship between changes in consumption and changes in the biological markers gamma-glutamyl transpeptidase (GGT) and average volume per erythrocyte (MCV) among problem drinkers

Co-variations between self-reported alcohol consumption and the biological markers MCV (average volume per erythrocyte) and GGT (gamma-glutamyl transpeptidase) over a 2-year period were studied in a group of 84 men and 53 women recruited to out-patient treatment by advertisements in the press. Upon admission, the drinking pattern of the participants during the preceding year was registered in detail. The participants were also medically examined, and blood samples taken. All the participants were followed up by new personal interviews, medical examinations and new blood sampling after 3, 9, 25 and 21 months. For the group as a whole, alcohol consumption was significantly lower at the end of the observation period than at admission. GGT was also decreased, but not MCV. Both self-reported consumption and the values for the biological markers showed large inter-individual and intra-individual variations during the observation period. The biological markers seemed to co-vary to a limited degree with changes in reported consumption. Both GGT and MCV seemed to have a low sensitivity but a high specificity to changes in consumption. Both markers also seemed to be somewhat more useful in identifying decreases than increases in consumption. The markers GGT and MCV should be used with caution in connection with therapeutic counselling to individuals.

Diffusion as a mechanism of postmortem drug redistribution: an experimental study in rats

In some cases of drug overdose there is a reservoir of unabsorbed drug in the stomach and gut. Furthermore, agonal aspiration might establish a second reservoir in the lungs. Two experimental rat models were used to study if diffusion from these reservoirs could contribute to the phenomenon of postmortem drug redistribution. Overnight fasted rats were sacrificed by CO2 and 75 mg of amitriptyline (AMI) was administered by a gastric tube. In the first series (n = 19), the tubes were removed after AMI administration. In the second series (n = 17), the trachea was ligated and cut prior to drug administration to prevent airways contamination. The rats were left at room temperature on their back for a period of 5, 10, 24, 48, 96 up to 192 h and samples of heart blood, blood from the inferior vena cava, tissue samples from heart, lungs, different liver lobes, kidney and psoas muscle were taken. In both series of rats we observed that as early as 5 h postmortem increasing concentrations of amitriptyline were found in the liver lobes lying closest to the stomach. In rats where the trachea was not ligated, drug contamination of the lungs also resulted in an increase in drug concentration within 5 h in heart blood and heart muscle. In rats where the trachea had been ligated, amitriptyline was found in the lungs after 96 h postmortem. The main metabolite nortriptyline was also detected.(ABSTRACT TRUNCATED AT 250 WORDS)

[Neurobiological aspects of addictive drugs]

Increasing insight into the molecular and cellular mechanisms of drugs of abuse has been obtained during the last decade. Such drugs exert several of the effects related to their abuse potential by interacting with the mesocorticolimbic dopaminergic system. Single doses of several drugs of abuse increase dopamine activity in nucleus accumbens, which is related to reward and reinforcement. Repeated administration may result in development of tolerance, but also in behavioral sensitization and conditioning. These processes alter subsequent drug-related behaviours and may contribute to relapse to drug taking.

Measuring ethanol in blood and breath for legal purposes: variability between laboratories and between breath-test instruments

We determined the concentrations of ethanol in nearly simultaneous specimens of venous blood (BAC) and end-expired breath (BrAC) after healthy volunteers drank moderate amounts of alcohol. BAC was measured at two laboratories and BrAC was analyzed with two instruments (Intoxilyzer 5000) from the same manufacturer. The mean difference in BAC between laboratories was 0.0105 mg/g (SD 0.0219); 95% of the differences ranged from -0.0333 to 0.0543 mg/g. The mean difference in BrAC between instruments was 0.0153 mg/L (SD 0.0136), and 95% of the differences ranged from -0.0119 to 0.0425 mg/L. The coefficient of variation (CV) between laboratories was 2.9% compared with 4.5% between breath-test instruments. Venous BAC (y) and BrAC (x) were highly correlated (r = 0.978). However, when the Intoxilyzer instruments indicated that BrAC had reached zero, the actual BAC was 0.135 mg/g, according to the average forensic laboratory reports. The Intoxilyzer 5000 breath analyzers used in this study seem to have a constant analytical bias.

Measuring Ethanol in Blood and Breath for Legal Purposes: Variability between Laboratories and between Breath-Test Instruments

We determined the concentrations of ethanol in nearly simultaneous specimens of venous blood (BAC) and end-expired breath (BrAC) after healthy volunteers drank moderate amounts of alcohol. BAC was measured at two laboratories and BrAC was analyzed with two instruments (Intoxilyzer 5000) from the same manufacturer. The mean difference in BAC between laboratories was 0.0105 mg/g (SD 0.0219); 95% of the differences ranged from -0.0333 to 0.0543 mg/g. The mean difference in BrAC between instruments was 0.0153 mg/L (SD 0.0136), and 95% of the differences ranged from -0.0119 to 0.0425 mg/L. The coefficient of variation (CV) between laboratories was 2.9% compared with 4.5% between breath-test instruments. Venous BAC (y) and BrAC (x) were highly correlated (r = 0.978). However, when the Intoxilyzer instruments indicated that BrAC had reached zero, the actual BAC was 0.135 mg/g, according to the average forensic laboratory reports. The Intoxilyzer 5000 breath analyzers used in this study seem to have a constant analytical bias.

Clinical responses in relation to blood acetaldehyde levels

A study was undertaken to examine the relationship between blood acetaldehyde levels and clinical responses in volunteers receiving the anti-alcohol drugs disulfiram and calcium cyanamide. In the first part of this study volunteers received different doses of disulfiram (125 mg and 500 + 250 mg), of calcium cyanamide (25 mg, 50 mg and 100 mg) and of ethanol (0.2 g/kg orally and 0.5 g/kg intravenously). The ensuing interactions ranged from no reaction at all to an intense hypotensive cyanamide-ethanol reaction (CER). A blood acetaldehyde concentration-effect relationship was suggested. In the second part of this study seven subjects received 50 mg of calcium cyanamide 4 hr prior to an intravenous ethanol dose of 0.2 g/kg. The maximum blood level of acetaldehyde ranged from 16 to 241 microM. Aversive interactions started to occur at acetaldehyde levels around 40-60 microM. Changes in flushing reaction and diastolic blood pressure appeared best to reflect changing blood acetaldehyde levels. As a rule, however, the expected cyanamide-ethanol and disulfiram-ethanol reactions are more clearly registered as an increase in acetaldehyde levels than as the ensuing physiological responses.

Relationship between drug plasma concentrations and psychomotor performance after single doses of ethanol and benzodiazepines

In a placebo controlled, crossover study psychomotor effects of single doses of diazepam, 10 and 20 mg, flunitrazepam, 1 and 2 mg, as well as 0.9 g ethanol/kg body weight were investigated over a time period of 6 h in 12 healthy men. Blood samples were collected simultaneously with the test sessions to determine drug concentrations in plasma or blood. The ethanol dose caused the least performance impairment, followed by 10 mg diazepam. The most pronounced impairment was caused by 2 mg flunitrazepam, whereas 20 mg diazepam and 1 mg flunitrazepam caused intermediate impairment and were approximately equipotent on group level. Considerable interindividual differences with respect to maximal impairment following a particular drug treatment were observed, with poor correlation between individual maximal impairments and individual peak plasma concentrations of the drug. The maximal impairment in simple reaction time following the flunitrazepam treatments occurred earlier relative to the peak plasma concentration of the drug as compared to the diazepam treatments. This may indicate that acute tolerance develops differently for the two drugs.

[Substance abuse analysis of biological materials]

Requests are increasing for biomedical analyses of abused drugs in forensic toxicology, tests at work, testing of drug addicts during rehabilitation, and in therapeutic and other situations. Special guidelines have been prepared in forensic toxicology, with regard to the legal background, information on any sanctions in the event of positive test results, chains of custody for handling samples, analytical methods with known specificity and sensitivity, and interpretation of results based on information of legal drug use. These guidelines should also be recommended in other cases if the results might lead to negative sanctions for the individuals involved. False positive test results have been recorded from cases analysed at local laboratories which had not established the recommended guidelines. The most critical point appears to be the confirmation of positive screening results using specific methods.

A case of high opiate tolerance: implications for drug analyses and interpretations

A case of driving under the influence of extremely high concentrations of codeine and ethylmorphine is reported. A high blood concentration of morphine was also found, which in this case was probably a metabolic product of codeine and ethylmorphine. This illustrates that when morphine is found in blood, the sample should also be analysed for other opiates in order to avoid misinterpretations.

Disulfiram implant: a double-blind placebo controlled follow-up on treatment outcome

Seventy-six alcohol-dependent patients participated in a study of the clinical effect of implanted disulfiram (DS). The patients were randomized to a DS group (n = 40), receiving a subcutaneous abdominal implantation of 10 x 100 mg DS tablets and a placebo group (PL group) receiving an implantation of 9 x 100 mg calcium phosphate tablets together with one calcium phosphate tablet containing 1 mg DS. Both groups believed they were receiving DS. At admission there was no significant difference between the DS and PL groups with regard to demographic characteristics, psychosocial adjustment, drinking variables, medical disorders, or laboratory results. After a study period of approximately 300 days, 63 patients (33 DS; 30 PL) were assessed using a battery of tests. There was no significant difference between the groups with regard to reduction in average alcohol consumption, number of days to the first alcohol intake after implantation, or level of psychosocial function. Nevertheless, both groups reduced their ethanol consumption significantly, probably due to the psychological deterrent effect. The DS implant did result in a significantly higher incidence of wound complications. This study does not support the idea that a 1-g DS implant has any significant clinical effect different from the implant containing only 1 mg DS (placebo).

Morphine-6-glucuronide might mediate the prolonged opioid effect of morphine in acute renal failure

1. A 43-year-old male developed acute kidney failure due to ethylene glycol poisoning. He was treated with bicarbonate to combat metabolic acidosis, ethanol as an antimetabolite and haemodialysis to remove the glycol and its toxic metabolites. He was kept on a respirator and sedated with morphine. Peritoneal dialysis was given for 36 d. Following sedation with morphine for 11 d, the patient was given naloxone and then extubated. The antidote had to be continued for 14 d to prevent respiratory depression, until kidney function improved. 2. Only morphine-6-glucuronide (M-6-G) was found in the plasma and CSF at concentrations which might explain the opioid effects observed in the patient during the days after the cessation of morphine treatment. The ratio of the area under the concentration-time curve (AUC) of morphine-3-glucuronide (M-3-G) to M-6-G was 2:1. The elimination half-lives of M-3-G and M-6-G were 55 and 82 h, respectively. The clearance data indicate that most of the glucuronides were eliminated by peritoneal dialysis during renal failure. 3. The data suggest that M-6-G exerts opioid effects and is retained in acute kidney failure. Morphine should therefore not be used preferentially as a sedative/analgesic in pronounced kidney failure.

Pharmacokinetics of trimeprazine in children

The pharmacokinetics of trimeprazine (alimemazine) were studied over 24 hr in six children after a recommended preanaesthetic oral dose of 3 mg.kg-1. The degree of sedation before anaesthesia was evaluated. Median maximal venous blood drug concentration was 0.357 mumols.1(-1), 1-2 hr after oral ingestion, half-life 6.8 hr and AUC0-infinity h 2.758 mumols.1(-1) hr. Assuming 100 per cent bioavailability, blood clearance was estimated to median 3.7 1.kg-1.hr-1. Trimeprazine concentrations in cerebrospinal fluid (CSF) and in venous blood were compared in three other children, measured by gas chromatography. No trimeprazine was detected in the cerebrospinal fluid. We found a rough correlation between preanaesthetic sedation and blood trimeprazine concentrations. The kinetic parameters showed substantial interindividual differences, and accordingly, major interindividual variations in drug response might be anticipated even on standardized dosage regimens.

[Identification of patients at risk of alcohol related damage]

Alcohol is clearly underestimated as an etiological factor in clinical medicine. A number of acute and chronic medical conditions are related to alcohol consumption, even when there are no signs of alcohol dependence. This article describes a new screening instrument proposed and developed by the WHO, AUDIT (Alcohol Use Disorders Identification Test), to be used in hospitals and general medical settings. The clinical component of this instrument is based on analyses of regular patients where the level of consumption was used as the dependent variable. This makes it possible to assess the extent and risk of alcohol-related problems without actually discussing alcohol with the patient. The alcohol-specific component can be used for a more detailed exploration of the patient's use of alcohol.

[Alcohol withdrawal--biological background, diagnosis and treatment]

Alcohol withdrawal reveals a condition of central nervous system (CNS) hyperexcitability opposite to that of the primary effect of the drug. Adaption to the decreased activity of the CNS during chronic ethanol ingestion may at least partly explain several of the symptoms of alcohol withdrawal. Benzodiazepines are therefore useful in the withdrawal state. The benzodiazepine loading dose technique, giving diazepam 20 mg every hour until the patient shows signs of clinical improvement and mild sedation, is the choice of treatment in cases of moderate to severe alcohol withdrawal. In general, neuroleptics should be avoided, because of increased risk of convulsions, but haloperidol can be used to control hallucinations and severe agitation. This treatment should then be combined with benzodiazepines. Most patients with mild withdrawal symptoms respond to non-pharmacological supportive care, except for those with a history of withdrawal seizures. These patients may need treatment with carbamazepine or diazepam.

[Disulfiram and calcium carbimide. Mode of action, adverse effects and clinical use]

The alcohol-sensitizing drugs disulfiram and calcium carbimide are often used in the treatment of alcohol problems with the hope of reducing alcohol consumption. These drugs inhibit the liver enzyme acetaldehyde dehydrogenase and, when taken prior to ethanol, produce an acetaldehyde-mediated aversive reaction. However, the drugs are unspecific, and several side effects may be related to their influence on other biochemical processes. These drugs are primarily pharmacological adjuncts and should be used in conjunction with behavioural and psychosocial therapies.

[Disulfiram implants. Lack of pharmacological and clinical effects]

The therapeutic rationale for using implanted disulfiram is possible inhibition of the liver enzyme acetaldehyde dehydrogenase, producing an acetaldehyde-mediated aversive reaction after intake of ethanol. Several studies using volunteers and patients in a double blind controlled study produced no evidence that a disulfiram implant (1 g) has any significant pharmacological or clinical action, except for a higher frequency of local surgical complications.

[The influence and use of drugs other than alcohol among drivers]

During the last few years, the National Institute of Forensic Toxicology has recorded an increasing number of cases of impaired driving due to drugs other than alcohol. Screening for drug use among drivers who are suspected of drunken driving only have also shown high frequencies of drug positive blood samples, indicating that a large number of drugged drivers are not discovered. Our results also show that the combined influence of both alcohol and drugs is common. Several new regulations were passed by the Norwegian Parliament in 1988 pursuant to the Norwegian Road Traffic Art. These new regulations include differentiation of sentences depending on blood alcohol concentration, introduction of evidential breath alcohol analysis and reduced use of clinical examination. The article discusses today's procedures for handling cases of suspected impairment by drugs. It is concluded that several problems will arise when dealing with cases of combined alcohol and drug impairment in accordance with the new Road Traffic Act, and that the introduction of evidential breath alcohol analysis and reduced use of clinical examination will make it more difficult to detect drugged drivers, particularly when they are also influenced by alcohol.

[Interactions between alcohol and drugs]

Interactions between ethanol and drugs are probably frequent, but few quantitative data are available on the magnitude of the problem. The interactions may be either pharmacodynamic (interactions at the site of drug action) or pharmacokinetic (interactions connected to drug absorption, distribution, metabolism and elimination). The most important interactions occur when ethanol and the drug are present in the organism at the same time. These direct interactions usually lead to supratherapeutic effects and unwanted side-effects, caused mainly by pharmacodynamic but also by pharmacokinetic mechanisms. The most serious interactions are seen with drugs which act on the central nervous system, and with anti-inflammatory drugs, anti-hypertensives and warfarin. Chronic drinking (above 50 g ethanol per day) for months may reduce the response to the drug in sober periods. These indirect interactions (increased tolerance to the drug) are due both to pharmacodynamic and pharmacokinetic mechanisms. Ceasing drinking will be followed by an increase in the efficacy of the drug in question. Long-term intake of ethanol (for years) may cause damage to organs, followed by increased sensitivity to many drugs.

Screening for drug use among Norwegian drivers suspected of driving under influence of alcohol or drugs

Two hundred and seventy blood samples selected at random from Norwegian drivers apprehended on the suspicion of drunken or drugged driving were screened for the presence of amphetamine, benzodiazepines, cannabinoids, tetrahydrocannabinol (THC) and cocaine. Of the samples tested, 223 were from drivers suspected of driving under the influence of alcohol only (A-cases). In the rest (n = 47) of the cases, the police also suspected drugs as a possible reason for driving impairment (D-cases). In the A-cases, benzodiazepines were found in 17%, cannabinoids in 26%, THC in 13% and amphetamine in 2% of the blood samples. One or more drugs besides ethanol were found in 38% of the A-samples. In the D-cases, benzodiazepines were found in 53%, cannabinoids in 43%, THC in 43%, amphetamine in 13% and 77% of these samples contained one or more drugs. Cocaine was not detected in any sample. Blood alcohol concentrations (BAC) above the legal limit of 0.05% were found in 80% of the drug positive A-cases and in 28% of the drug positive D-cases. The frequency of drug detection in A-samples was similar (40%) in samples with BAC above and below 0.05%, while this frequency was much higher (above 90%) in D-samples with BAC below 0.05% than in D-samples with BAC above 0.05% (53%). Benzodiazepines were most frequently found among drivers above 25 years of age, while cannabinoids were most frequently found among drivers below 35 years. For about 15-20% of the A-cases with BAC below 0.05%, other drugs were detected at concentrations which may cause driving impairment. It was concluded that analysis of alcohol only might often be insufficient in A-cases to reveal driving impairment.

A double-blind placebo controlled study of healthy volunteers given a subcutaneous disulfiram implantation

A study was carried out to elicit information of the pharmacological effect of implanted disulfiram (DS). Healthy volunteers were randomized to either of two groups; six were given 1 g DS implant and six subjects placebo (PL) implants. Each participant was subjected to one intravenous ethanol challenge before, and six intravenous ethanol challenges as well as one oral ethanol challenge after the implantation. No clinical signs of disulfiram-ethanol reactions (DER) were observed. The intravenous challenges did not result in any significant differences between pre- and post-implantation values for blood acetaldehyde concentrations in the DS group, and these values were not significantly different from the corresponding values in the PL group. However, somewhat higher blood acetaldehyde concentrations were recorded after an oral ethanol dose (0.8 g/kg) in the DS group. In a longitudinal study with oral ethanol challenges after implanted DS, one of three healthy volunteers had a significant higher blood acetaldehyde concentration three weeks after the implantation, while no such tendency was found in any subject tested earlier or later in the post-implantation period. The blood acetaldehyde levels after oral challenges were, however, far too low to produce a DER.

Screening for drugs in forensic blood samples using EMIT urine assays

A screening method for the detection of drugs in haemolysed whole blood has been evaluated. Methanolic extracts of 300 forensic blood samples known to be positive or negative for drugs were analysed with EMIT d.a.u. assay kits for amphetamine, cannabinoids, opiates and benzodiazepines (the latter to analyse for diazepam and the main metabolite N-desmethyldiazepam). There were very few false positive results, except for the amphetamine assay in postmortem blood samples, where 9% were false positive. For amphetamine and cannabinoids a few false negatives were found, these were from samples with very low drug concentrations. No false negatives were found for opiates and diazepam. The present modification of the EMIT d.a.u. method seems to be a good method for screening of drugs in forensic blood samples, except for amphetamine in postmortem samples. The method is simple and requires only 0.5 ml blood.

Ethanol elimination-rates determined by breath analysis as a marker of recent excessive ethanol consumption

The rate of ethanol elimination was studied in two groups of men by means of an Alcotest 7010 breath analyser. The experimental group consisted of 15 skid-row alcoholics undergoing detoxification. Their median daily ethanol consumption was 211 (range 26-476) g pure ethanol during the last year. The control group was made up of 12 age-matched healthy social drinkers consuming 9 (range 4-23) g day-1 pure ethanol during the last year. The median ethanol elimination-rate in the elimination phase was 0.25 (range 0.13-0.31) g 1-1 h-1 during the detoxification period in the experimental group. This value was approximately 70% higher than in the control group (0.14(0.12-0.17) g 1-1 h-1). Some correlation was found between reported ethanol intake, and the calculated ethanol elimination-rate, as well as gamma glutamyl transferase (GGT), alanine amino transferase (ALAT), aspartate amino transferase (ASAT), glutamate dehydrogenase (GLDH), mean corpuscular volume (MCV) and HDL-cholesterol. Of these measures, ethanol elimination-rate showed highest sensitivity and efficiency for detection of ethanol consumption above the limit of 50 g per day.

Thyrotropin-releasing hormone antagonism of ethanol inebriation

The effect of ethanol [1 g/kg per orally (p.o.) during 1 hr] after thyrotropin-releasing hormone (TRH) pretreatment (five doses of 20 mg p.o. during 30 hr preceding ethanol intake) was studied in a placebo-controlled, double-blind design in 11 healthy subjects. Computerized reaction tests measuring errors and reaction time, as well as clinical testing and a self evaluation (modified Osgood test) were performed before, 75, 150, and 225 min after ethanol intake. TRH treatment did not influence blood ethanol concentrations. The effect of ethanol to produce errors was substantially reduced in all three reaction tests after TRH treatment compared to placebo treatment. The reaction times were slightly increased in simple and four choice reaction tests and up to 20% increased in a complex test in the TRH-ethanol situation compared to the placebo-ethanol situation. The effects caused by ethanol were also significantly reduced in three clinical tests and in two subjective tests of inebriation by TRH treatment compared to placebo treatment. In conclusion the study demonstrated that several acute effects of ethanol intake in humans were reduced by TRH pretreatment which did not interfere with the blood ethanol concentration versus time curve.

Reduced IgG Fc-receptor-mediated phagocytosis in human monocytes isolated from alcoholics

Blood monocytes (MC) were isolated from alcoholics and from age-matched controls. Phagocytosis mediated by the IgG Fc-receptor (Fc-R) was assessed in the MC immediately after isolation by using IgG-opsonized sheep erythrocytes as test particles. Experiments were also performed after preincubating the MC in medium containing 10% autologous serum with or without ethanol (80 mM) in vitro at 37 degrees C for 15 min, and with or without ethanol (80 mM) present during the internalization assay in vitro (37 degrees C for 60 min). MC from alcoholics exhibited lower phagocytic capacity via the Fc-R than MC from healthy controls, approximately 50% versus 70% phagocytosing cells. Preincubation of the MC in medium containing 10% autologous serum with 80 mM ethanol, reduced the percentage of phagocytosing MC from controls to 55%, whereas no further reduction occurred in cells from alcoholics. When present during the assays of Fc-R function, ethanol decreased MC phagocytosis of IgG-coated particles significantly in both test groups, to about 30% phagocytosing cells. Blood samples disclosed increased serum levels of markers of liver dysfunction, immunoglobulins, increased sedimentation rate, and white blood cell counts among the alcoholics, while their serum levels of 1,25-dihydroxyvitamin D3 were reduced.

Some aspects of antioxidant status in blood from alcoholics

The effect of ethanol consumption on serum concentration of alpha-tocopherol, erythrocyte activities of superoxide dismutase, glutathione peroxidase, and catalase were studied in 34 male alcoholics and 35 age-matched controls. Serum concentration of alpha-tocopherol was 30% lower in the alcoholics as compared to the controls (p less than 0.001). No significant difference was found in erythrocyte activities of Cu-Zn-containing superoxide dismutase, glutathione peroxidase, or catalase between the groups. Of the 12 alcoholics with subnormal serum alpha-tocopherol, 50% had concomitant neurological clinical scores and cerebellar atrophy, and their neurological scores were significantly higher (82%) than for alcoholics with normal alpha-tocopherol levels (p less than 0.03). However, no significant correlation was observed between levels of alpha-tocopherol and neurological clinical scores or cerebellar atrophy. When entering the study, alcoholics and controls were each randomized into two separate groups, receiving vitamin E supplementation (100 mg/day) or placebo capsules for 10 days, respectively. In the four subgroups, alpha-tocopherol levels increased only in alcoholics receiving vitamin E supplementation (23%) (p less than 0.001). The reduced serum levels of alpha-tocopherol in alcoholics may be normalized by vitamin E supplementation.

Interference with analysis of amphetamine in blood by N-ethylbenzenamine from rubber septums

When blood stored in glass vials sealed with natural rubber septums was screened for amphetamine, a contaminant was seen. The contamination originated from the rubber septums and was identified by GC/MS as N-ethylbenzenamine. Like amphetamine, N-ethylbenzenamine was extracted from strongly alkaline solutions. N-Ethylbenzenamine and amphetamine chromatographed with the same retention time on a packed Apiezon/KOH column and on nonpolar capillary columns. Separation was achieved on a medium polar capillary column. Trifluoroacetyl derivatives of amphetamine and N-ethylbenzenamine had the same retention time on a packed SP-2250 column, but separated on nonpolar capillary columns. The amounts of N-ethylbenzenamine found were high enough to give rise to significant false positive results if N-ethylbenzenamine was erroneously read as amphetamine. N-Ethylbenzenamine is believed to be formed by thermal decomposition of the vulcanizing agent zinc ethylphenyldithiocarbamate used in rubber production.

Calcium status and calcium-regulating hormones in alcoholics

To elucidate effects of chronic ethanol consumption on clinical chemical parameters reflecting overall calcium homeostasis 34 hospitalized male alcoholics and 35 age-matched controls were studied during the winter season. Serum concentrations of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 were reduced by 28% (p less than 0.01) and 24% (p less than 0.02) among the alcoholics as compared to the controls, respectively. Dietary intake of vitamin D3 did not differ significantly between the groups. The calcium level was below lower limit of reference in nine alcoholics (26%). Serum concentrations of parathyroid hormone and phosphorus were within normal ranges in both groups, and no differences were observed in levels of magnesium, vitamin D-binding protein, calcitonin, or alkaline phosphatase. In conclusion, it is possible that the activities of enzymes crucial in vitamin D3 metabolism may be altered in alcoholics.

A two year prospective study of rearrests for drunken driving

393 drunken drivers, arrested within a six-month period in 1984/85, were selected for a prospective study of rearrests for drunken driving. Within the following two years, 119 (30%) of the drivers were rearrested. They were responsible for 232 detected drunken driving offences. The rearrest rate increased with increasing blood alcohol concentration (measured at the time of selection). The rearrest rate was greater for those with elevated blood gamma glutamyltransferase (a marker of excessive alcohol consumption), and was markedly greater for those with more than one arrest for drunken driving preceding the observation period.

An experimental study on ethanol elimination at subphysiological temperatures

Hepatocytes isolated from fed and fasted rats have been used to study the rate of ethanol elimination at different incubation temperatures. In the presence of exogenous pyruvate, hepatocytes from fed and 42 hr fasted rats, eliminated ethanol at 37 degrees by a rate of 11.6 +/- 3.4 and 6.4 +/- 0.8 nmol/min./mg of cell protein (+/- S.D.; n = 5), respectively, which are comparable to the rates obtained in vivo. The ethanol oxidation rate in cells from rats of both nutritional states correlated linearily to the incubation temperature (t = 24-37 degrees) with a temperature coefficient (Q10) of 1.8-2.3. (Q10, (= temperature coefficient) is the factor by which the enzyme activity is increased on raising the temperature 10 degrees). These findings indicate that the oxidation is not controlled by processes which involve membrane transitions in the temperature range 24-37 degrees. Our results indicate that a hypothermic individual with a body temperature of 27 degrees would have a 40-50 per cent inhibition of the ethanol elimination rate. Thus, the observed dependency of the ethanol oxidation on the body temperature has to be regarded in back-calculations of blood ethanol concentrations in forensic toxicology.

A comparison of serum carbohydrate-deficient transferrin with other biological markers of excessive drinking

In a study of suggested biological markers of excessive drinking, serum carbohydrate-deficient transferrin (CDT) was compared with serum activities of alanine aminotransferase, alkaline phosphatase, amylase, aspartate aminotransferase and gamma glutamyltransferase; serum concentrations of high-density lipoprotein cholesterol; and erythrocyte mean cellular volume. Analytical data were studied in relation to self-reported alcohol consumption during the latest month for the 69 participating subjects. CDT was found to be the most sensitive and most specific marker of excessive drinking, and was also found to be the best marker for monitoring abstinence under treatment of alcoholics.

Diminished serum concentration of vitamin E in alcoholics

The effect of heavy alcohol consumption on serum concentrations of vitamin E (alpha-tocopherol) and selenium was studied in 13 alcoholics and 19 control subjects. Ethanol intake during the year previous to the study was in the range from 22 to 354 g/day and from 0 to 16 g/day among the alcoholics and controls, respectively. Of the 13 alcoholics, 6 had a serum concentration of alpha-tocopherol below the lower limit of reference (14 mumol/l) and mean serum concentration of alpha-tocopherol was reduced by 37% as compared to controls (p less than 0.002). Estimated dietary intake of alpha-tocopherol during the year previous to the study was approximately 40% lower for the alcoholics (p less than 0.05). During hard-drinking periods the alcoholics had a markedly reduced intake of alpha-tocopherol as compared to moderate-drinking and abstinent periods. Mean serum concentration of selenium was significantly reduced in the alcoholics (1.2 +/- 0.3 mumol/l) as compared to the controls (1.6 +/- 0.2 mumol/l) (p less than 0.002). The reduced serum levels of alpha-tocopherol and selenium may influence the maintenance of normal cell structure and function, and contribute to development of diseases frequently observed in alcoholics.

Oral administration of codeine in the presence of ethanol: a pharmacokinetic study in man

Three healthy male volunteers were given a codeine (1 mg/kg) solution in the absence and presence of ethanol in a cross-over designed study. The blood ethanol concentration was kept at approximately 16 mM for 8 hrs. Blood samples were taken at several occasions during the first day after the codeine administration. Urine was sampled during three days. There were no significant differences in the area under serum concentration versus time curve in the absence and presence of ethanol with respect to free codeine, total codeine and total morphine. The fraction of codeine glucuronized in serum (approximately 94%), the maximum serum concentration of free (0.34 microM) and total codeine (6.3 microM), the time to reach the maximum serum concentration values (approximately 65 min.) were also similar in the absence and presence of ethanol. The accumulated percentage of the codeine dose given which was found as codeine and morphine and their conjugates in the urine ranged from 50 to 91 percent in the different subjects. The accumulated percentage of the administered codeine dose found as free morphine in the urine, was significantly lower in the ethanol exposed individuals (0.18 +/- 0.03%) compared to the controls (0.39 +/- 0.09%). The percentage of the codeine dose found in the urine in the control situation as free codeine (5.2 +/- 2.2%) was not statistically different from the amount found in the urine after ethanol treatment (4.3 +/- 2.0%). The percentage glucuronized morphine (95.3 +/- 0.4%) and codeine (91.9 +/- 2.2%) in the urine in the absence of ethanol was similar to glucuronized morphine (95.3 +/- 2%) and codeine (93.1 +/- 3%) after ethanol exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of ethanol on human monocyte IgG Fc receptors

The IgG Fc receptor function of human monocytes (Mo) exposed to ethanol in vitro was assessed by a rosette assay in which IgG-coated sheep red blood cells were used as test particles. Pre-incubation of Mo in autologous serum with ethanol (55 mM and above) for 15 min at 37 degrees C, caused a significantly lower percentage of Mo-forming rosettes. This reduction by ethanol was not observed when Mo were preincubated with ethanol in fetal calf serum or in serum-free conditions, but was present when Mo were pre-incubated with ethanol in serum-free media to which IgG (10-150 micrograms/ml) had been added. Donor-dependent differences were observed in the reduction of Mo-forming rosettes in the presence of autologous serum and ethanol. Mo allowed to form rosettes without ethanol were exposed to ethanol during a subsequent phagocytosis process. A dose-dependent inhibition of the internalization of test particles was found in Mo from all donors.