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Pharmacodynamics and Pharmacokinetics of Alcohol A.W. Jones, PhD, DSc Department of Forensic Toxicology, University Hospital, 581 85 Linköping, Sweden. [email protected] Presented at meeting of the California Association of Toxicologists, Santa Rosa, CA, 1-2 August, 2003. Pharmacokinetics Studies of the movement of drugs into, within and out of the body What the body does to the drug CH3CH2OH Pharmacodynamics Studies of the effect and mechanism of action of drugs on the body What the drug does to the body Pharmacokinetics Pharmakon = drug or poison Kinesis = movement The discipline known as pharmacokinetics deals with the way that drugs and their metabolites are absorbed, distributed, and eliminated in the body and how these processes can be described in quantitative terms. Pharmacokinetics of ethanol • Forensic pharmacokinetics – Widmark’s model • One-compartment, zero-order elimination – Michaelis-Menten elimination • Saturable kinetics – dose dependent • First-order kinetics – Operates at very low & perhaps at very high BAC? • Multicompartment models – Arterial and venous blood compartments • Physiologically-based kinetic models – PB-PK • Population kinetics Forensic Pharmacokinetics Peak BAC Blood Ethanol, mg/dl 150 Drinking Spree Rise in BAC 100 50 Time to Peak β -slope 0 0 30 60 90 120 150 180 210 240 Time After Start of Drinking, min 270 300 Pharmacokinetic Models V Dose ko Dose C 1.2 km C Vmax 1.2 1 1 Blood Ethanol, g/L Blood Ethanol, g/L V 0.8 0.6 0.4 0.2 0.8 0.6 0.4 0.2 0 0 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 Time, h -dc/dt = ko Ct = Co - kot Time, h -dc/dt = Vmax x C km + C Response feature analysis of BAC profiles - noncompartmental analysis 200 Blood Ethanol, mg/dl Peak BAC Typical curve after intravenous Infusion 150 Diffusion plunge 100 β -slope = Co/Mino Co 50 First-order kinetics AUC Mino 0 0 100 200 300 400 500 600 Time After Start of Infusion, min 700 Important articles on EtOH kinetics • Widmark – Principles and application of medicolegal alcohol determination. Biomedical Publications, Foster City, CA, 1981 (tanslation of Widmark’s 1932 German monograph) • Lundquist & Wolthers – Acta Pharmacol & Toxicol 1956;14:265-289. • First application of Michaelis-Menten kinetics, thanks to use of more sensitive enzymatic ADH method for blood-alcohol analysis • VonWartburg – Chapter in ”Human metabolism of alcohol” (vol 1, Crow and Batt, editors) CRC Press, 1989, pp 9-22. • Comprehensive review of ethanol pharmacokinetics as well as applications in forensic casework. Important articles on EtOH kinetics • Wilkinson – Alcohol. Clin. Exp. Res. 1980;4:6-21. • Comprehensive review of ethanol pharmacokinetics with emphasis on Michaelis-Menten equation. • Holford – Clin. Pharmacokinet. 1987;13:273-292 • Comprehensive review of clinical pharmacokinetics of ethanol • Kalant – Chapter in ”Pharmacology of alcohol and alcohol dependence” (Begleiter & Kissin, editors) Oxford University Press, 1996, pp 15-58. • Norberg et al – Clin. Pharmacokinet. 2003;42:1-31 • Comprehensive review of clinical pharmacokinetics of ethanol with focus on variability and forensic issues. Properties of the Drug Ethyl Alcohol CH33CH22OH • Small molecule (MW 46.05). • Unionized at physiological pH and carries only a weak charge • Dosage form (beer, wine, spirits). • Easily passes biological membranes. – Including blood-brain barrier • Completely miscible with water. • Low solubility in lipids and bone. • Negligible binding to plasma proteins. Analytical Considerations • Choice of biofluid for analysis – blood, plasma, urine, saliva, breath • Different kinetic parameters Vd ko and t½ • Sampling variations – Pre-analytical factors • Sampling site, technique, transport, storage, stability, preservatives? • Choice of method of analysis – Enzymatic (ADH) or gas chromatoraphy – Calibration standards • External controls, tracability? – Headspace gas chromatography currently considered gold standard method Precision, Accuracy, Specificity Within laboratory precision 0.5-1.5% CV Between Laboratory Variation • Forensic Labs* • Clinical Chemistry Labs CV = 2-3% CV = 6-9% * Laboratories specializing in blood-ethanol assays and using standardized routines based on headspace GC and internal standard, etc. Use of breath-alcohol analyzers Seemingly increasing (non-invasive) • Breath-alcohol concentration follows arterial and not venous blood-alcohol concentration. • The venous blood-breath ratio of alcohol is a moving target. • What blood/breath factor was used for calibration? – Details rarely given. • Results depend on pre-exhalation pattern. Screening device for police use Pharmacodynamics Studies of biochemical and physiological effects of drugs on living organisms including mechanisms of action, dose response relationships, and drug-effects on behavior in relation to chemical structure and dosage form. Pharmacodynamics of ethanol • How EtOH drinking influences the behavior and the actions of an individual – Metabolic effects • Metabolism of ethanol produces energy 7.1 kcal per g – Central Nervous System (CNS) effects – Ethanol as a psychotropic drug – Impairment of performance and behavior • Mechanisms of action – Intermediary metabolism – Cell membranes – Receptor sites and ion channels Can EtOH be compared with inhaled anesthetics? Hydrocarbons & chlorocarbons Ethers Diethylether Ethylene Chloroform Others Cyclopropane N2O Xe Halothane Enflurane Methoxyflurane Isoflurane Servoflurane Mechanism of anesthesia Lipid solubility (Meyer-Overton correlation) Disruption of lipid bilayer Interaction with specific receptors (GABA, NMDA) The Cell Membrane Meyer-Overton observed that the potencies of anesthetic drugs are directly proportional to their lipid solubilities - disrups lipid portion of cell membrane. Muscle Relaxant Benzodiazepines Anticonvulsant CH3 O N Cl Anxiolytic N Diazepam Sedative Hypnotic BAC vs Effects close to peak concentration BAC [%] Effects of alcohol on the individual 0.02-0.03 Mood elevation. Slight muscle relaxation. 0.05-0.06 Feelings of relaxation and warmth. Increased reaction time. Decreased fine muscle coordination. 0.08-0.09 Impaired balance, speech, vision, hearing, muscle coordination. Marked euphoria. 0.14-0.15 Gross impairment of physical and mental control. 0.20-0.30 Severely intoxicated loss of control of mind and body. 0.40-0.50 Unconscious. Deep coma. Death from respiratory depression. Alcohol Dose 1.25 g/kg (277 mL or 9.2 oz whisky/70 kg man) 10 8 BAC 110 mg/dL 150 6 100 4 Intoxication Score 50 2 0 0 0 Alha, 1951 1 2 3 4 Time After Drinking, h 5 6 Intoxication Score (symptoms) Blood Alcohol mg/dl 200 Suspected drunk drivers (N = 1453) apprehended by the police and examined by different physicians who concluded they were not under the influence of alcohol BAC, g% 0.00-0.049 Number of cases 431 Percent not under influence 30% 0.05-0.099 441 30% 0.10-0.149 360 25% 0.15-0.159 161 11% 0.20-0.249 51 3.5% 0.25-0.299 10 0.7% Suspected drunk drivers (N= 244) apprehended by the police and examined by the same physician to assess whether they were under the influence of alcohol. BAC g% Number No Slightly Moderatly Severly 0.00-0.049 29 39 54 47 47 25 3 3 2 2 1 - 26 37 41 24 20 7 1 0.05-0.099 0.10-0.149 0.15-0.199 0.20-0.249 0.25-0.299 0.30-0.349 10 17 22 11 1 1 5 5 7 1 Altered synaptic activity caused by ethanol working at multiple molecular sites • Neurotransmitter systems – – – – Dopamine (5HT3) - excitatory GABAA - inhibitory Glycine - inhibitory Glutamate (NMDA)* - excitatory • Excitation & dependence • Dopamine, 5HT3 • Sedation and intoxicating effects • GABA, glycine, glutamate • No known antagonist of EtOH seemingly exists • RO15-4513 had some potential * N-methyl-D-aspartate receptor Receptors involved in some of the actions of ethanol Effects on ligand-gated ion channels GABAA inhibitory receptor EtOH potentiates the effect of GABA GABA Receptor Benzodiazepine receptor Barbiturate receptor Chloride channel Effects of Ethanol on the Brain Alcohol is not evenly distributed in the brain. Concentrations depend on blood flow and water content. • Impairment of cognitive and psychomotor functions • First emotion and decision making e.g. reasoning, thinking, learning and judgement • Next muscular control e.g.marked impairment of movement, balance, speech, reaction time etc. • Last affected is respiration and circulation (v. high BAC). • Degree of impairment depends on dose, rate of drinking and prior experience with alcohol Tolerance Acute Tolerance • From studies mainly in dogs, Mellanby found that the degree of impairment to alcohol was greater at a given blood-alcohol concentration on the rising portion of the blood-alcohol curve than it was at the same concentration on the descending part of the curve. – Some toxicologists considered that the Mellanby effect was caused by the different alcohol concentration in arterial blood reaching the brain and the venous blood returning from muscle tissue, which was assumed to be the specimen analyzed. Widmark’s definitions • Consumption Tolerance – For a given consumption of alcohol, different blood alcohol concentrations are reached for different individuals. • This depends on different patterns of absorption, distribution and elimination and body composition. • Concentration Tolerance – This relates to the concentration of alcohol in blood causing effects on the individual. The intensity of these symptoms differs between individuals at the same blood-alcohol concentration. • The mechanism of concentration tolerance relates to the effects of alcohol on the brain – acute and chronic tolerance. Tolerance • Dispositional Tolerance – Changes in absorption, distribution, excretion and metabolism of the drug which might lead to a reduction in intensity and duration of the effects on the individual. • Functional Tolerance – Changes in sensitivity of the brain or other tissue making it less sensitive to the same degree of exposure to the drug. Definitions given by Dr. Harald Kalant, Toronto. Pharmacological Reviews 23;1971, pp 135-191. Alcohol in the Body • Absorption phase • Distribution phase • Elimination phase – Metabolism • Oxidation & conjugation – Excretion Rate of Absorption • Depends on many factors – Route of administration • Inhalation, sub- and per-cutaneously, intravenously, rectally, perorally. – Dosage form • Beer, wine, distilled spirits • Dilution and CO2 content • Buffer capacity – Gastric emptying • Food, time of day, blood-glucose 1.2 Esophagus Pyloric sphincter Blood Ethanol, g/L 1 0.8 0.6 0.4 0.2 Slow absorption across stomach wall 0 0 1 2 3 4 5 6 7 8 Time, h 1.2 1 Blood Ethanol, g/L Rapid absorption from duodenum Slow gastric emptying 0.8 Rapid gastric emptying 0.6 0.4 0.2 0 0 1 2 3 4 5 6 7 8 Time, h Critical Role of Stomach Emptying on Peak BAC • Man 80 kg, drank 190 ml whisky over 60 min, venous BAC at 5.35 p.m. was 0.052 g% • Man 88 kg, drank 190 ml whisky over 60 min venous BAC at 5.50 p.m. was 0.011 g% • Man 75 kg, drank 190 ml whisky over 60 min venous BAC at 5.46 p.m. was 0.049 g% Pyloric Sphincter Distribution phase • Depends on many factors; – Water content of the various fluids and tissues • More H20 more alcohol. – Importance of ratio of blood flow (F) to tissue mass (M). • Low ratio F/M large A-V difference – Body water depends on age, gender and the proportion of fat to lean tissue (obesity). – Widmark’s rho-factor Measuring Total Body Water ! Isotope dilution methods ! Water labelled with deuterium ! Water labelled with tritium ! H2O18 ! Ethanol dilution ! Bioelectrical impedance measurements ! Anthropometric measurements ! Age, weight, and height ! Weight/height2 (kg/m2) body mass index Widmark’s experimental conditions 1. Twenty healthy men and ten healthy women all of whom were moderate drinkers. 2. Rapid ingestion of spirits (30-40% v/v) in a single moderate dose (0.5-0.9 g/kg) on an empty stomach (overnight fast). 3. Sampling and analysis of fingertip capillary blood at 30-60 min intervals for 6-7 hours. 4. Reporting concentrations of ethanol in mg ethanol per gram blood (not per mL). 1. Average rho men 0.68, rho women 0.55 2. Average ß men 0.15, ß women 0.16 Watson, Watson and Batt J. Stud. Alcohol 42;547-556, 1981 ! They derived multiple regression equations to express the relationship between TBW and a persons age, gender, height, and weight. ! For men the height was not so important for the calculation of TBW. ! For women neither age nor height were seeminly vital for calculation of TBW. Anthropometric Measurements • Healthy Men – TBW = 20.03 - 0.1183 yr + 0.3626 kg • Male 32 y, 65 kg, TBW = 39.8 L (61.2%) • Standard deviation 3.86 liters (CV = 9.7%) • Healthy Women – TBW = 14.46 + 0.2549 kg • Female 65 kg, TBW = 31.0 L (47.7%) • Standard deviation 3.72 Liters (CV = 12%) • Rho-factor = (water in body)/(water in blood) • Blood water = 82-85 % w/v Estimating Total Body Water (TBW) by the Ethanol Dilution Method ! Conditions* p.o. Fasting (0.68 g/kg) 20-29 y 30-39 y 40-49 y 44.2 L 47.8 L (60.2%) (59.1%) Anthropometric 44.4 L data** (60.8%) 45.6 L (56.5%) Infusion of ethanol (0.6 g/kg) Anthropometric data** 50-59 y 47.9 L 46.5 L (56.7%) (55.3%) 46.5 L (55.1%) TBW TBW 45.3 L (53.9%) 40.3 L (50.1%) 42.1 L (52.9%) Men aged 62 y (span 55-68 y) * N = 12 men per age group. * * Watson, Watson, Batt. Recent Update of Widmark’s rho Factor ! Widmark rho for men ! 0.31608 – 0.004821 weight (kg) + 0.004632 height (cm) ! Widmark’s rho for women ! 0.31223 – 0.006446 weight (kg) + 0.004466 height (cm) ! These equations were evaluated in controlled drinking experiments. Seidel et al, Int. J. Legal Med.114;71-77, 2000 Elimination process • Metabolism + excretion – Metabolism - oxidation • Various enzyme systems involved – ADH, ALDH, CYP2E1, Catalase? • Conjugation – Ethyl glucuronide – Excretion • Passive diffusion – Breath, Sweat, Urine Organs Absorption phase Hepatic metabolism First pass metabolism Phase I enzymes Phase II enzymes Excretion processes Urine Breath First-Pass Metabolism Oral Dose Class IV ADH Gut Class I ADH Liver Sampling Compartment I.V. administration sidesteps problems with first-pass metabolism First-Pass Metabolism ! Defined as the loss of drug as it passes through the gastro-intestinal membranes and the liver, for the first time, during the absorption process Much research has focused on the role of alcohol dehydrogenase located in the gastric mucosa, so called gastric ADH (Class IV) as site of first-pass metabolism with a high km for ethanol oxidation. age sex race body mass index Dose State of health; liver kidney gut The Individual The Environment Concentration of Ethanol in Blood Pathophysiology Genetics and genomics smoking drinking food drugs Speed of drinking Activity of hepatic enzymes polymorphism Inter-individual Variations Alcohol and aldehyde dehydrogenase enzymes Methanol Alcoholdehydrogenase (ADH) NAD+ Ethanol Formaldehyde NADH Aldehydedehydrogenase (ALDH) NAD+ Acetaldehyde ADH1 ADH2*1, ADH2*2, ADH2*3 ADH3*1, ADH3*2 Located in cytosol Formate NADH Acetate ALDH1 ALDH2*1, ALDH2*2 Located in mitochondria Intra-individual Variations Intra-individual variations Male Subject 23 y 40 g ethanol in 5 min empty stomach Blood Alcohol mg/g 1.0 0.8 N = 10 experiments During 9 weeks β = 0.157 mg/g/h (range 0.14 - 0.20) 0.6 0.4 0.2 0 0 100 200 Time after bolus intake, min 300 Intra-individual variations in EtOH elimination rate from blood N = 12 male subjects consumed EtOH 0.8 g per kg body weight on 4 occasions after an overnight fast. Elimination rate β-slope g/dl/h 0.020 0.015 0.010 Mean value of ß-slope 0.0142 g%/h, range 0.0117-0.0173 g%/h 0.005 0.00 1 2 3 Alcohol Drinking Session BJCP 35;427-431, 1994 4 Inter- vs intraindividual variation not significantly different by ANOVA Conjugation ethyl glucuronide < 1% Ethanol CYP2E1 microsomes ~10% Chemically reactive 3-5% ADH Excretion breath, urine, sweat cytosol ~85% Acetaldehyde Toxic metabolite ALDH mitochondria H2 O Acetate coenzyme A CO2 Breath Urine Sweat ~5% CH3CH2OH NAD+ H+ + NADH ~0.1% ~94% Alcohol Dehydrogenase (ADH) Ethyl glucuronide EtOH > 0.06 g% CH3CHO NAD+ Aldehyde Dehydrogenase (ALDH) CYP2E1 H+ + NADH CH3COOH CO2 CH3CHO H2O Metabolic disturbances during hepatic oxidation of ethanol • Altered hepatic redox state owing to increae in the NADH/NAD+ ratio means; – Pyruvate is converted to lactate which competes with ureate for excretion via kidney and results in uric acid accumulation and gout and lactacidosis. – Hepatic synthesis of glucose is impaired • hypoglycemia – Reduced citric acid cycle (excess acetyl CoA) – Promotion of fatty acid synthesis • Risk for ketoacidosis – Reduced lipid oxidation • Accumulation of fat in hepatocytes. Long-term effects of chronic heavy drinking on the liver Fatty liver, hepatitis and fibrosis are intermediate stages, although these are reversible. Healthy liver removed at autopsy Cirrhotic (orange) liver removed at autopsy Drug-Alcohol Interactions • Pharmacokinetic (metabolic) Interactions – Effects on absorption, distribution, elimination • Acute vs chronic intake – metabolic tolerance? • Competition for metabolizing enzymes (CYP450) • Influence on stomach emptying • Pharmacodynamic Interactions – Acute vs chronic intake – CNS tolerance? – Synaptic activity • binding to receptor sites, opening of ion channels Alcoholdehydrogenase Methanol Aldehydedehydrogenase Formaldehyde NAD+ NADH Ethanol NAD+ Formate NADH Acetaldehyde Acetate Alcoholdehydrogenase Aldehydedehydrogenase Blocked by 4-methyl pyrazole Blocked by Disulfiram fomepizole (Antizol®) Antabuse® Drug alcohol metabolic interactions at specific enzymes • Alcohol dehydrogenase – 4-methyl pyrazole, other alcohols, chloral hydrate • Aldehyde dehydrogenase – Disulfiram, calcium carbimide, • CYP2E1 – Acetaminophene, chlormethiazole • Drugs used in treatment of stomach problems – Histamine-H2-antagonists inhibitors of gastric ADH? • Cimetidine (Tagamet®) • Ranitidine (Zantac®) – Proton-pump inhibitors • Omeprazole (Losec®) H N H3C NCN Histamine H N N CH3NHCNHCH2CH2SCH2 N NH 2CH 2CH 2 Cimetidine (Tagamet®) H 4-methyl pyrazole Fomepizole Antizol® H 3C N N Jönsson et al. Eur J Clin Pharmacol 42;209-12, 1992 (A) 25 20 15 10 A = Cimetidine 7 days B = Ranitidine 7 days C = Omeprazole 7 days compared with no-drug treatment, EtOH 0.8 g/kg -1 Blood Ethanol (mmol l ) 5 0 (B) 25 20 15 10 5 0 (C) 25 20 15 10 5 0 0 1 2 3 4 Time (h) 5 6 Many studies used very small doses of alcohol e.g. 0.150.30 g/kg and found small increases in peak BAC 0.008-0.015 g/100 mL Moderate Drinker Drug CYP450 + EtOH X Drug Metabolites Heavy Drinker Drug Activated CYP450 Drug Metabolites X Prolonged Therapeutic Effect of the Drug Diminished Therapeutic Effect of the Drug Sulfate conjugate ~35% Glucuronide conjugate ~60% Acetaminophene CYP2E1 ~5% Induced by alcohol, fasting, protein deficiency N-acetyl-p-benzoquinone imine (NAPQI) Reactive intermediate Glutathione inactivation Glutathione conjugate Covalent binding to tissues – cell death Hepatotoxicity Toxicity of Ethanol Some Factors to Consider • • • • • • Age, gender, body mass index Dose, beverage type, speed of drinking Route of administration Hypothermia Development of chronic tolerance General state of health – Malnutrition, metabolic disorders, ketoacidosis • Concomittant use of other drugs – CNS depressants – Opiates • Evidence of positional asphyxia or inhalation of vomit. At what blood-concentration does alcohol kill? Different authorities cite different concentrations derived presumably from personal experiences but where is the documentation? Bernard Knight (UK) >0.30 g% DiMaio & DiMaio (USA) 0.40 g% We recently looked at all deaths in Sweden attributed to acute alcohol poisoning with alcohol as the only drug present in femoral venous blood Gender N Blood Alcohol Mean Age Male 529 0.355 g% 54 y Female 164 0.373 g% 53 y Jones and Holmgren, J. Forensic Sciences (USA), July 2003 Deaths Ascribed to Acute Alcohol Poisoning 250 250 Normal 200 Frequency Acute Alcohol Poisoning Deaths N = 693 Mean 0.36 g/100 mL Median 0.36 g/100 mL 200 150 150 100 100 50 50 0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 Blood-Ethanol Concentration, g/100 mL 0 0.7 Deaths Ascribed to Chronic Alcoholism Frequency (%) 30 30 Indications N = 703 Mean 1.70 g/L Median 1.50 g/L Range 0.1 to 5.6 g/L 20 20 10 10 0 0.0 1.0 2.0 3.0 4.0 5.0 0 6.0 Blood-Ethanol Concentration, g/L • • • • • • • • Fatty Liver Hepatitis Cirrhosis Pancreatitis Cardiomyopathy Ascites Psychoses Ketoacidosis Drunk drivers in Sweden with very high blood-ethanol conc., > 0.4 g% (N = 120)* Gender (body weight) N (%) Mean BAC g% EtOH in body, g 5 h** metabolism Male (75 kg) 107 (89%) 0.428 225 g (710 mL vodka) 265 g (810 mL vodka) 0.435 159 g (530 mL vodka) 199 g (570 mL vodka) Female (65 kg) 13 (11%) * Swedish records (0.545, 0.544, 0.518, 0.505, g%) ** 8 g/h = 40 g = ~100 mL spirits Physiological range of ethanol elimination rates from blood BAC rate of Conditions or treatment decline g% per h 0.08-0.010 People with liver dysfunction (e.g. cirrhosis) or those who are malnourished, eat low-protein diets or take a drug that blocks ADH e.g. fomepizole (4-methyl pyrazole) 0.010-0.013 Healthy people who drink moderate amounts of alcohol after an overnight fast. 0.013-0.016 Healthy people who drink moderate dose of ethanol under non-fasting conditions. 0.016-0.025 Heavy drinkers such as drunk drivers who reach appreciably high BAC (> 0.12 g/100 mL) 0.025-0.035 Alcoholics during detoxification or binge drinkers immediately after heavy drinking. Treatment with protein or amino acid rich diets or those suffering from conditions leading to a hypermetabolic state. t1 t2 Time Blood Alcohol Conc. Blood Alcohol Conc. Rate of ethanol elimination in drinking drivers? t1 Time Assuming post-absorptive phase and zero order kinetics J. Forensic Sci. Vol 41, 922-926, 1996. Example of calculating elimination rates based on double blood samples Case (blood) 1a Time BAC g% Pair of of day bloods 20.39 0.248 1a_1b BAC rate of decline g%/h 0.019 1b 21.42 0.228 1a_1c 0.020 1c 22.05 0.220 1b_1c 0.021 2a 05.55 0.217 2a_2b 0.021 2b 06.15 0.210 2a_2c 0.020 2c 07.35 0.183 2b_2c 0.020 ß-Slope as a Function of Age in Male and Female DWI Suspects Blood-Alcohol Decay Rate, mg/ml/h 0.30 0.30 Women Men 0.25 0.25 0.20 0.20 0.15 0.15 0.10 0.10 0.05 0.05 0.00 <20y 20-29y 30-39y 40-49y Age 50-59y >60y 0.00 Frequency Ethanol elimination rate in DWI suspects 250 250 200 200 Derived from double blood samples • Mean 0.019 g% per h 150 150 100 100 50 50 • SD 0.005 g% per h • Median 0.019 g% per h • Min 0.00 g% per h • Max 0.046 g% per h 0 0.00 0.01 0.02 0.03 0.04 0 0.05 Elimination Rate, g/100 mL per h • 95% range (± 2 SD) • 0.009 – 0.029 g% per h Gender Differences Kwo et al. Gastroenterology 115;1552-57, 1998 • Different body composition. – Less water/kg in women compared with men lower volume of distribution in women. • Hormonal differences – testosterone influences ADH activity? • • • • • First-pass metabolism - gastric ADH? Menstrual cycle in women? Oral contraceptive steroids? Liver volume ~same Alcohol Elimination rate per kg LBM was higher in women. Relationship between dose of ethanol and Cmax and AUC of the BAC profile Blood-Ethanol, g/100 mL 0.15 0.10 (2) 0.05 (4) 0.95 g/kg (3) 0.64 g/kg (2) 0.80 g/kg 0.32 g/kg 0 0 60 120 180 240 300 360 420 Time From Start of Drinking, min 480 540 Blood-Ethanol Profiles N = 48 Healthy Men Aged 20-59 y 0.68 g/kg Neat whisky in 20 min Empty stomach Blood Ethanol mg/100 mL 140 120 100 • Conditions 80 60 40 20 0 0 60 120 180 240 300 360 Time After Start of Drinking, min Work done at Karolinska Institute - police as subjects 420 480 – – – – – – Healthy men 20-59 y Neat whisky 0.68 g/kg Empty stomach 20 min drinking time – Capillary blood samples Blood Ethanol elimination, g/L/h Rank ordering of blood-ethanol elimination rates in fasting male subjects 0.20 0.20 Mean 0.126 g/L/h (N = 48) SD 0.0173 g/L/h 95% range 0.091 - 0.16 g/L/h 0.15 0.15 0.10 0.10 0.05 0.05 0.00 0.00 10 20 30 Subject Number 40 Times needed to reach Cmax after drinking neat whisky on empty stomach Dose g/kg 0.34 0.51 0.68 0.85 1.02 All N 6 16 83 44 3 152 5-15 min 5 11 33 13 62 (41%) 35-45 min 1 3 26 24 1 55 (36%) 65-75 min 1 21 7 1 30 (20%) 95-105 min 1 3 1 5 (3%) Note times might be different under social drinking conditions Time to Cmax after end of drinking Time to reach peak BAC, Cmax Number of subjects (%) 0 min 4 (6%) 15 min 19 (29%) 30 min 17 (26%) 60 min 19 (29%) 90 min 3 (4%) 120 min 1 (1.4%) N = 65 men drank 0.8 g ethanol/kg as 95% v/v alcohol diluted with orange juice in 30 min after overnight fast. Time to Reach Peak Concentrations under Social Drinking Conditions • Wright and Cameron, Alc & Alcoholism 33;495-501, 1998. – 51 subjects drank 1 mL EtOH/kg as beer (4% v/v) over 90 min (~2 L ) and breath analyzed 5-90 min after end of drinking. • Peak BrAC at mean time of 16 min (range 5-85 min). • Ganert and Bowthorpe, Can Soc Forens Sci J. 33;137-43, 2000 – 10 subjects drank 0.37-0.52 g alcohol per kg per hour over 3 hours. Breath was analyzed at 5-10 min intervals for up to 7 hours after start of drinking. • Peak BrAC at mean time of 12 min (range 4-22 min). Zink & Reinhardt, Blutalkohol 21;422-433, 1984. 4.5 SUBJECT 2 EOD = 620 m in Blood Ethanol, mg/g 4.0 3.5 3.0 2.5 Peak BAC 608 m in 2.0 1.5 Ingestion of 364 g ethanol (5.7 g/kg) mainly as 4 vol% Beer 1.0 0.5 0 0 200 400 600 800 1000 Time From Start of Drinking, min 1200 Zink & Reinhardt, Blutalkohol 21;422-433, 1984. 3.5 SUBJECT 1 Blood Ethanol, mg/g 3.0 EOD = 580 m in 2.5 2.0 Peak BAC 575 m in 1.5 1.0 Ingestion of 357 g ethanol (4.7 g/kg) mainly as 4 vol% Beer and spirits 0.5 0 0 200 400 600 800 1000 Time From Start of Drinking, min 1200 Mean Curves Effect of beverage type, data from Finland 1.8 Brandy Beer Blood Ethanol, g/kg 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 60 120 180 240 300 Time, min Brandy N = 12 men Brandy (1.0 g EtOH per kg) Blood Ethanol, g/kg 2.0 1.5 1.0 0.5 0.0 0 60 120 Beer 2.5 180 Time, min 240 N = 12 men Beer (1.0 g EtOH per kg) 2.0 Blood Ethanol, g/kg 2.5 300 1.5 1.0 0.5 0.0 0 60 120 180 Time, min 240 300 Inter-individual variation and gender differences 0.7 Blood Ethanol, g/L Blood Ethanol, g/L N = 22 subjects 10 men and 12 women 0.4 g/kg 0.8 ETHANOL DOSE 0.4 g/kg 0.7 0.6 MEN WOMEN 0.5 0.4 0.3 0.2 0.1 0.0 0 60 120 180 Time after start of drinking, min 0.6 (g/kg)/0.7 0.5 0.4 0.3 0.2 0.1 0.0 240 0 60 120 180 Time, min 240 300 300 0.6 Mean Curves (N = 9) Blood Ethanol, g/L 0.5 Plasma vs whole blood as specimens for analysis 0.4 Plasma 0.3 0.2 Whole Blood 0.1 0 0 60 120 180 240 Time, min 0.6 0.6 Male 66 kg 0.5 Blood Ethanol, g/L Blood Ethanol, g/L 0.5 Male, 65 kg 0.4 Plasma 0.3 0.2 Whole Blood 0.4 0.2 0.1 0.1 0 0 0 60 120 Time, min 180 240 Plasma 0.3 Whole Blood 0 60 120 Time, min 180 240 1.4 Healthy subject, 0.8 g ethanol per kg in 15 min after overnight fast. Drink Blood Alcohol, g/L 1.2 Radial Artery Blood 1.0 0.8 0.6 Cubital Venous Blood 0.4 0.2 0 0 60 120 180 240 300 Time, min 360 420 480 1.0 Blood Ethanol, g/L 0.8 Male, 70 kg, 32 y 70 mL whisky 70 mL whisky 0.6 0.4 0.2 55 min 0.0 0 60 1.0 Blood Ethanol, g/L 0.8 120 180 240 300 Time, min 360 420 480 540 360 420 480 540 Man, 64 kg, 33 är 64 mL whisky 0.6 64 mL whisky 0.4 0.2 60 min 0.0 0 60 120 180 240 300 Time, min Drnking alcohol on an empty stomach in divided doses showing slower absorption of the second dose Concentration-time profiles of ethanol in urine Blood Urine Ethanol Conc., g/L 2.0 1.5 1.0 0.5 0.0 0 100 200 300 400 500 Time After Start of Drinking, min 600 Concentration-time profiles of ethanol in saliva Saliva Ethanol Conc., g/L 1.6 0.54 g/kg 0.68 g/kg 0.85 g/kg 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 60 120 180 240 300 Time, min 360 420 480 540 Ethanol Conc. g/L 0.6 CSF Blood 0.5 0.4 0.3 0.2 0.1 0.0 0 60 120 180 Time After Drinking, min Ethanol Conc. g/L 0.6 CSF Blood 0.5 0.4 0.3 0.2 0.1 0.0 0 60 120 Time After Drinking, min 180 Concentration-time profiles of ethanol in serial samples of lumbar cerebrospinal fluid ETHANOL-FOOD INTERACTION • • • • Lowers the Peak BAC Smaller Area Under the Curve Diminished Feelings of Intoxication Shorter Time to Zero BAC •More rapid metabolism Influence of food on ethanol parameters Empty stomach After food 1.5 C 0 (fast) Widmark's rho Dose (g/kg)/C 0 Blood Ethanol, g/L C 0 (fed) 1.0 C t = C 0 - ßt 0.5 Time0 0 0 60 120 180 240 300 Time, min 360 420 480 540 Effect of Eating a Meal Before Drinking Mean Curves n = 12 150 150 0.80 g/kg Empty stomach 100 Blood Ethanol, mg/dl Blood-ethanol mg/dl Man 43 y, 68 kg Ethanol dose 0.8 g/kg Fasted β = 13.5 mg/dl/h After food 100 50 0 50 0 60 120 180 Time, min Fed β = 14.3 mg/dl/h 0 0 1 2 3 4 5 6 7 Time from start of drinking 8 9 240 300 360 Inter-individual variations A. Drinking on empty stomach Ethanol dose 0.3 g/kg, 10 male subjects B. Drinking 60 min after breakfast C. Drinking 60 min after breakfast + aspirin 0.6 0.4 0.2 0 0.4 0.2 60 120 Time, min 180 240 0.4 0.2 0 0 0 C 0.6 B Blood Ethanol, g/L A Blood Ethanol, g/L Blood Ethanol, g/L 0.6 0 60 120 Time, min 180 240 0 60 120 Time, min 180 240 Pharmacokinetics in people with GERD Trial 1 Trial 2 Blood Ethaol, g/L 0.8 0.6 0.4 0.2 0.0 0 50 100 150 200 250 300 Time, min 0.8 Blood Ethanol, g/L Trial 1 Trial 2 J. Forensic Science 1999;44:814-819 0.6 0.4 0.2 0.0 0 50 100 150 Time, min 200 250 300 Pharmacokinetics in women after gastric bypass surgery Upper gastrointestinal canal after operation for gastric bypass. The volume of new stomach is ~25 mL. This operation often leads to mean body weight reduction of 25-40% within 3 to 5 years. Representative BAC Profile GASTRIC BYPASS PATIENTS 1.2 15_F KM F, 44 y, 74 kg, 167 cm Blood Alcohol, g/L 1.0 0.8 0.6 0.4 0.2 0 0 60 120 180 TIme from start of drinking, min 240 Mean Curves, N = 13 subjects. Brit J. Clin. Pharmacol Dec., 2002 Blood Alcohol, g/L 0.80 0.60 Operated Control 0.40 30 min 0.20 0 0 60 120 180 TIme from start of drinking, min 240 Disease States and Rate of Ethanol Disappearance from Blood Jokipii, MD Thesis, University of Helsinki 1951 • • • • • • Healthy Controls (N = 42) Dystonia (N = 17) Hepatitis (N = 19) Cirrhosis (N = 5) Hyperthyreosis (N = 15) Diabetes Mellitus (N = 21) 0.013 g/100 mL/h 0.010 g/100 mL/h 0.010 g/100 mL/h 0.010 g/100 mL/h 0.014 g/100 mL/h 0.011 g/100 mL/h Combined results of experiments with men and women who drank 0.50 g/kg (40% v/v) as a bolus dose on an empty stomach Rate of Ethanol Elimination in Alcoholics (induced CYP2E1 activity) • • • • Male and female alcoholics. BAC at start of detoxification 0.23 - 0.49 g% w/v. 6-8 specimens of venous blood taken over 24 h. Blood-ethanol determined by headspace gas chromatography. • Rate of ethanol disappearance from blood calculated as described by Widmark from the slope of the elimination phase. β = 0.024 g% per h SUBJECT 2 2.5 400 2.0 300 1.5 200 1.0 100 0.5 0 0 0 5 10 15 20 25 Time From Start, h 500 3.0 Subject 7 0.5 0.4 0.3 0.2 0.1 0 β = 0.021 g% per h 0.5 0.4 0.3 0.2 0.1 0 β = 0.022 g% per h 2.5 400 2.0 300 1.5 200 1.0 100 0.5 0 0 0 5 10 15 20 25 Time From Start, h 0 3 6 9 12 15 18 21 TIME FROM START, h 24 27 EtOH-MeOH metabolic interaction Blood Methanol, mg/dl 0.5 0.4 0.3 0.2 0.1 0 Blood Ethanol, mg/dl β = 0.019 g% per h F Blood Ethanol, mg/dl BLOOD ALCOHOL CONCENTRATION, g% w/v Alcoholics Blood Methanol, mg/dl 3.0 500 0.5 0.4 0.3 0.2 0.1 0 Faster Elimination Rate in Alcoholics during Detoxification* Subject • • • • • • • • 1 2 3 4 5 6 7 8 BAC at Start ß-slope g% per h 0.443 g% 0.489 g% 0.398 g% 0.454 g% 0.359 g% 0.343 g% 0.337 g% 0.410 g% 0.018 g% per h 0.021 g% per h 0.028 g% per h 0.017 g% per h 0.019 g% per h 0.016 g% per h 0.017 g% per h 0.033 g% per h Mean rate (N = 21), 0.023 g% per h (0.013-0.036) *Alcohol & Alcoholism 27;641-647, 1992 Jones, unpublished work Blood Alcohol, mg/dl 150 Subject Vomited and Comatose 125 100 75 50 M 110 kg Alcohol dose 1.02 g/kg 330 ml neat whisky in 25 min 25 0 0 1 2 3 4 5 6 Time From Start of Drinking, h 7 Retrograde Extrapolation Position of the BAC profile at the time of driving? Was alcohol consumed after driving? Was BAC or BrAC measured? What allowance if any should be made for absorption of alcohol contained in the last drink? ! Allowance for a rising BAC or BAC plateau? ! Was a urine sample taken? ! ! ! ! ! Can help to verify post-absorptive state ! What elimination rate (ß-slope) should apply? Exact quantitative results are probably not possible Retrograde Extrapolation ! Provided that the BAC curve was post-peak at the time of driving and the time of drawing blood then back extrapolation is feasible and simple. ! Ct1 = C0 - ßt1 and Ct2 = C0 - ßt2 ! Ct1 = Ct2 + (ß x tdiff) ! In criminal cases best to assume a low rate of alcohol elimination (ß-slope) such as 0.01 g% per hour. See Stowell and Stowell, JFS, 43;14-21, 1998 Forward Prediction of BAC ! This application of Widmark’s equation has been widely abused and has considerable uncertainty owing to assumptions about the rate of absorption and first-pass metabolism that might occur. ! If alcohol is taken with food then the dose of alcohol available for absorption into the blood is less by 10-20%. ! Drinking heavily over many hours seems to result in larger “losses” of alcohol. See Zink & Reinhardt , Blutalkohol 21; 422-442, 1984. Arterial-Venous Differences in EtOH Conc. at the Blood Sampling Compartment Tissue of the Arm Peripheral vein CA CV Peripheral artery High water content of muscle acts as a reservoir for ethanol Male subjects A-V Difference g/L 0.5 0.4 A-V Difference g/L 0.4 0.3 Mean ± SD N = 9 Subjects 0.3 0.2 0.1 0.0 -0.1 0.2 -0.2 0 60 120 0.1 180 240 300 Time 0.0 -0.1 -0.2 0 60 120 180 240 300 Time After Start of Drinking, min 360 360 Arterial-Venous Differences in Blood Ethanol Concentration • ABAC > VBAC during the absorption and distribution stages during and shortly after drinking – mean 0.019 g% (range 0.008 to 0.043 g%). • Occurred 10 min after end of drinking. • ABAC = VBAC at only one time point – 90 min (median) range 45-150 min. – Represents equilibriation in all body water • ABAC < VBAC at all later times – mean -0.0029 g/L (range -0.0018 to -0.0052). Studies in Progress • Pharmacokinetics of ethanol in obese subjects – People with very high BMI > 35 – What is volume of distribution of ethanol? – What consequences for Widmark calculatiosn? • Magnitude and time course of arterial-venous differences in ethanol concentration. – Implications for use of evidential breath-alcohol analyzers. • Comparison of glucose and amino acids on rate of alcohol metabolism – Both ethanol and nutrients given intravenously to sidestep confounding influences of gastric emptying. ”Is this really necessary, your Honor? I’m an expert.”