Gastric origin of the first-pass metabolism of ethanol in humans: effect of gastrectomy

Site of Alcohol First-Pass Metabolism Among Women

This cross-sectional study compares alcohol pharmacokinetics in patients who underwent sleeve gastrectomy with control participants who did not undergo surgery.

Comparison of ethanol concentrations after drinking in patients who underwent total gastrectomy versus healthy controls

BACKGROUND

The safety of drinking in patients who have undergone total gastrectomy for gastric cancer has not been established. We conducted a clinical trial to investigate the trend in alcohol absorption in actual patients.

METHODS

Patients who received total gastrectomy with lymph-node dissection and Roux-en-Y reconstruction six or more months ago were enrolled. Participants drank 1 unit (20 g) of ethanol within 1 h starting at least 1 h after a meal. The blood alcohol concentration (BAC) was then estimated by a measurement of the breath alcohol concentration. The peak and trend in the BAC in patients was compared with that in healthy volunteers who were matched with patients for the alcohol-sensitive genotype.

RESULTS

Ten patients and 10 healthy people were enrolled in the BAC evaluation. The peak BAC (%) was 0.158 in patients after total gastrectomy versus 0.110 in control (P < 0.001). The mean half-life of BAC was 58.0 min in the patient group and 94.0 min in the control group, although the mean time to complete drinking was significantly longer in the patient group than in the control group at 40.8 versus 21.9 min (P = 0.009).

CONCLUSION

Drinking alcohol is likely to carry a risk of increasing the BAC in patients who have undergone total gastrectomy.

Muscle Glycogen Utilization during Exercise after Ingestion of Alcohol

PURPOSE

Ingested ethanol (EtOH) is metabolized gastrically and hepatically, which may influence resting and exercise metabolism. Previous exercise studies have provided EtOH intravenously rather than orally, altering the metabolic effects of EtOH. No studies to date have investigated the effects of EtOH ingestion on systemic and peripheral (e.g., skeletal muscle) exercise metabolism.

METHODS

Eight men (mean ± SD; age = 24 ± 5 yr, body mass = 76.7 ± 5.6 kg, height = 1.80 ± 0.04 m, V˙O2peak = 4.1 ± 0.2 L·min) performed two bouts of fasted cycling exercise at 55% V˙O2peak for 2 h, with (EtOH) and without (control) prior ingestion of EtOH 1 h and immediately before exercise (total dose = 0.1 g·kg lean body mass·h; 30.2 ± 1.1 g 40% ABV Vodka; fed in two equal boluses) in a randomized order, separated by 7-10 d.

RESULTS

Muscle glycogen use during exercise was not different between conditions (mean [normalized 95% confidence interval]; EtOH, 229 [156-302] mmol·kg dm, vs control, 258 [185-331] mmol·kg dm; P = 0.67). Mean plasma glucose concentrations during exercise were similar (control, 5.26 [5.22-5.30], vs EtOH, 5.34 [5.30-5.38]; P = 0.06). EtOH ingestion resulted in similar plasma nonesterified fatty acid concentrations compared with rest (control, 0.43 [0.31-0.55] mmol·L, vs EtOH, 0.30 [0.21-0.40] mmol·L) and during exercise. Plasma lactate concentration was higher during the first 30 min of rest after EtOH consumption (mean concentration; control, 0.83 [0.77-0.90] mmol·L, vs EtOH, 1.00 [0.93-1.07] mmol·L), but the response during exercise was similar between conditions.

CONCLUSIONS

Muscle glycogen utilization was similar during exercise with or without prior EtOH ingestion, reflected in similar total whole-body carbohydrate oxidation rates observed.

Incidence and Risk Factors Associated With 30-Day Readmission for Alcoholic Hepatitis

BACKGROUND

Alcohol abuse and liver disease are associated with high rates of 30-day hospital readmission, but factors linking alcoholic hepatitis (AH) to readmission are not well understood. We aimed to determine the incidence rate of 30-day readmission for patients with AH and to evaluate potential predictors of readmission.

METHODS

We used the Nationwide Readmissions Database to determine the 30-day readmission rate for recurrent AH between 2010 and 2014 and examined trends in readmissions during the study period. We also identified the 20 most frequent reasons for readmission. Multivariate survey logistic regression analysis was used to identify factors associated with 30-day readmission.

RESULTS

Of the 61,750 index admissions for AH, 23.9% were readmitted within 30-days. The rate of readmission did not change significantly during the study period. AH, alcoholic cirrhosis, and hepatic encephalopathy were the most frequent reasons for readmission. In multivariate analysis female sex, leaving against medical advice, higher Charlson comorbidity index, ascites, and history of bariatric surgery were associated with earlier readmissions, whereas older age, payer type (private or self-pay/other), and discharge to skilled nursing-facility reduced this risk.

CONCLUSIONS

The 30-day readmission rate in patients with AH was high and stable during the study period. Factors associated with readmission may be helpful for development of consensus-based expert guidelines, treatment algorithms, and policy changes to help decrease readmission in AH.

Alcoholic Liver Disease: Current Mechanistic Aspects with Focus on Their Clinical Relevance

The spectrum of alcoholic liver disease (ALD) is broad and includes alcoholic fatty liver, alcoholic steatohepatitis, alcoholic hepatitis, alcoholic fibrosis, alcoholic cirrhosis, and alcoholic hepatocellular carcinoma, best explained as a five-hit sequelae of injurious steps. ALD is not primarily the result of malnutrition as assumed for many decades but due to the ingested alcohol and its metabolic consequences although malnutrition may marginally contribute to disease aggravation. Ethanol is metabolized in the liver to the heavily reactive acetaldehyde via the alcohol dehydrogenase (ADH) and the cytochrome P450 isoform 2E1 of the microsomal ethanol-oxidizing system (MEOS). The resulting disturbances modify not only the liver parenchymal cells but also non-parenchymal cells such as Kupffer cells (KCs), hepatic stellate cells (HSCs), and liver sinusoidal endothelial cells (LSECs). These are activated by acetaldehyde, reactive oxygen species (ROS), and endotoxins, which are produced from bacteria in the gut and reach the liver due to gut leakage. A variety of intrahepatic signaling pathways and innate or acquired immune reactions are under discussion contributing to the pathogenesis of ALD via the five injurious hits responsible for disease aggravation. As some of the mechanistic steps are based on studies with in vitro cell systems or animal models, respective proposals for humans may be considered as tentative. However, sufficient evidence is provided for clinical risk factors that include the amount of alcohol used daily for more than a decade, gender differences with higher susceptibility of women, genetic predisposition, and preexisting liver disease. In essence, efforts within the last years were devoted to shed more light in the pathogenesis of ALD, much has been achieved but issues remain to what extent results obtained from experimental studies can be transferred to humans.

[Alcohol and the Bariatric Patient: When One Drink Becomes Two Drinks]

Alcohol and the Bariatric Patient: When One Drink Becomes Two Drinks Abstract. Moderate consumption of alcohol is a risk factor for weight gain and obesity. Alcohol affects all components of the energy balance. Alcohol consumption is - as in the general population - also a widespread phenomenon in obese and bariatric patients. As a function of the bariatric surgery technique, alcohol metabolism is altered: gastric bypass surgery and sleeve gastrectomy lead to a faster absorption of alcohol, higher peak alcohol concentration and a longer alcohol persistence in the circulation. Further reward mechanisms for alcohol are changed, so that alcohol consumption is enhanced and promoted, with an increased risk to develop alcohol dependency. It is time to address these issues in the daily practice and to fill the existing research gaps.

Alcoholic Liver Disease: Alcohol Metabolism, Cascade of Molecular Mechanisms, Cellular Targets, and Clinical Aspects

Alcoholic liver disease is the result of cascade events, which clinically first lead to alcoholic fatty liver, and then mostly via alcoholic steatohepatitis or alcoholic hepatitis potentially to cirrhosis and hepatocellular carcinoma. Pathogenetic events are linked to the metabolism of ethanol and acetaldehyde as its first oxidation product generated via hepatic alcohol dehydrogenase (ADH) and the microsomal ethanol-oxidizing system (MEOS), which depends on cytochrome P450 2E1 (CYP 2E1), and is inducible by chronic alcohol use. MEOS induction accelerates the metabolism of ethanol to acetaldehyde that facilitates organ injury including the liver, and it produces via CYP 2E1 many reactive oxygen species (ROS) such as ethoxy radical, hydroxyethyl radical, acetyl radical, singlet radical, superoxide radical, hydrogen peroxide, hydroxyl radical, alkoxyl radical, and peroxyl radical. These attack hepatocytes, Kupffer cells, stellate cells, and liver sinusoidal endothelial cells, and their signaling mediators such as interleukins, interferons, and growth factors, help to initiate liver injury including fibrosis and cirrhosis in susceptible individuals with specific risk factors. Through CYP 2E1-dependent ROS, more evidence is emerging that alcohol generates lipid peroxides and modifies the intestinal microbiome, thereby stimulating actions of endotoxins produced by intestinal bacteria; lipid peroxides and endotoxins are potential causes that are involved in alcoholic liver injury. Alcohol modifies SIRT1 (Sirtuin-1; derived from Silent mating type Information Regulation) and SIRT2, and most importantly, the innate and adapted immune systems, which may explain the individual differences of injury susceptibility. Metabolic pathways are also influenced by circadian rhythms, specific conditions known from living organisms including plants. Open for discussion is a 5-hit working hypothesis, attempting to define key elements involved in injury progression. In essence, although abundant biochemical mechanisms are proposed for the initiation and perpetuation of liver injury, patients with an alcohol problem benefit from permanent alcohol abstinence alone.

Life course socioeconomic position, alcohol drinking patterns in midlife, and cardiovascular mortality: Analysis of Norwegian population-based health surveys

BACKGROUND

Socioeconomically disadvantaged groups tend to experience more harm from the same level of exposure to alcohol as advantaged groups. Alcohol has multiple biological effects on the cardiovascular system, both potentially harmful and protective. We investigated whether the diverging relationships between alcohol drinking patterns and cardiovascular disease (CVD) mortality differed by life course socioeconomic position (SEP).

METHODS AND FINDINGS

From 3 cohorts (the Counties Studies, the Cohort of Norway, and the Age 40 Program, 1987-2003) containing data from population-based cardiovascular health surveys in Norway, we included participants with self-reported information on alcohol consumption frequency (n = 207,394) and binge drinking episodes (≥5 units per occasion, n = 32,616). We also used data from national registries obtained by linkage. Hazard ratio (HR) with 95% confidence intervals (CIs) for CVD mortality was estimated using Cox models, including alcohol, life course SEP, age, gender, smoking, physical activity, body mass index (BMI), systolic blood pressure, heart rate, triglycerides, diabetes, history of CVD, and family history of coronary heart disease (CHD). Analyses were performed in the overall sample and stratified by high, middle, and low strata of life course SEP. A total of 8,435 CVD deaths occurred during the mean 17 years of follow-up. Compared to infrequent consumption (

CONCLUSIONS

Moderately frequent consumers had a lower risk of CVD mortality compared with infrequent consumers, and we observed that this association was more pronounced among participants with higher SEP throughout their life course. Frequent binge drinking was associated with a higher risk of CVD mortality, but it was more uncertain whether the risk differed by life course SEP. It is unclear if these findings reflect differential confounding of alcohol consumption with health-protective or damaging exposures, or differing effects of alcohol on health across socioeconomic groups.

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Key Words Collapse

MESH Headings

• Adult
• Alcohol Drinking/epidemiology
• Cardiovascular Diseases/epidemiology
• Cardiovascular Diseases/etiology
• Cardiovascular Diseases/mortality
• Female
• Follow-Up Studies
• Humans
• Male
• Middle Aged
• Norway/epidemiology
• Proportional Hazards Models
• Prospective Studies
• Risk Factors
• Socioeconomic Factors

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Grants

• MC_UU_00011/1 Medical Research Council
• Norges Forskningsråd

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Affiliation(s)

Eirik Degerud Norwegian Institute of Public Health, Oslo, Norway
Inger Ariansen Norwegian Institute of Public Health, Oslo, Norway
Eivind Ystrom Norwegian Institute of Public Health, Oslo, Norway Department of Psychology, University of Oslo, Oslo, Norway School of Pharmacy, University of Oslo, Oslo, Norway
Sidsel Graff-Iversen Norwegian Institute of Public Health, Oslo, Norway
Gudrun Høiseth Norwegian Institute of Public Health, Oslo, Norway Diakonhjemmet Hospital, Center for Psychopharmacology, Oslo, Norway
Jørg Mørland Norwegian Institute of Public Health, Oslo, Norway Institute of Clinical Medicine, University of Oslo, Oslo, Norway
George Davey Smith MRC Integrative Epidemiology Unit, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
Øyvind Næss Norwegian Institute of Public Health, Oslo, Norway Institute of Health and Society, University of Oslo, Oslo, Norway

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Sleeve gastrectomy surgery: when 2 alcoholic drinks are converted to 4

BACKGROUND

While it is well established that Roux-en-Y gastric bypass (RYGB) causes a rapid and heightened peak blood alcohol concentration (BAC), results from previous studies on the effects of sleeve gastrectomy (SG) on alcohol pharmacokinetics are conflicting. Data from 2 studies found SG did not affect BAC, whereas another study found SG caused a heightened peak BAC after alcohol ingestion. Moreover, these 3 studies estimated BAC from breathalyzers, which might not reliably estimate peak BAC.

OBJECTIVES

The aims of this study were to evaluate (1) the effect of SG, relative to RYGB and a presurgery group, on alcohol pharmacokinetics and subjective effects, and (2) whether breathalyzers are reliable in this population.

SETTING

Single-center prospective nonrandomized trial.

METHODS

We performed alcohol challenge tests in 11 women who had SG surgery 1.9 ± .1 years ago (body mass index = 35.1 ± 6.6 kg/m²), 8 women who had RYGB surgery 2.2 ± .4 years ago (body mass index = 30.0 ± 5.2 kg/m²), and 9 women who were scheduled for bariatric surgery (body mass index = 44.1 ± 4.0 kg/m²). BACs were estimated from breath samples and measured by gas chromatography at various times after consuming approximately 2 standard drinks.

RESULTS

BAC increased faster, peak BAC was approximately 2-fold higher, and feelings of drunkenness were heightened in both SG and RYGB groups relative to the presurgery group (P values<.001). BAC estimated from breath samples underestimated BAC by 27% (standard deviation = 13%) and missed peak BACs postsurgery.

CONCLUSIONS

SG, similar to RYGB, causes marked alterations in the response to alcohol ingestion manifested by a faster and higher peak BAC. The breathalyzer is invalid to assess effects of gastric surgeries on pharmacokinetics of ingested alcohol.

Obesity and addiction: can a complication of surgery help us understand the connection?

Obesity is a multifactorial, chronic disease that has proven difficult to treat. An increased understanding of aetiological mechanisms is critical to the development of more effective obesity prevention and treatment strategies. A growing body of empirical evidence has demonstrated parallels between obesity, overeating and substance abuse, including shared behavioural, psychological and neurophysiological factors implicated in the excessive intake of both food and substances of abuse. Several different lines of research have recently emerged that hold the potential to shed light on the connection between obesity, food reward and addiction, with studies examining changes in alcohol use/misuse after weight loss surgery providing a particularly interesting perspective on these interrelationships. However, these lines of investigation have proceeded in relative isolation, and relevant research findings have yet to be integrated in a synthesized, comprehensive manner. To provide an opportunity to achieve such a synthesis, a scientific symposium was convened at the Radcliffe Institute in Cambridge, Massachusetts. Invited participants were researchers working in diverse domains related to the intersection between obesity and addiction. Extensive discussion was generated suggesting novel research directions. In this article, we summarize and synthesize the symposium participants' ongoing research in this area, incorporating additional relevant research holding potential clues regarding the connections between obesity, weight loss surgery and addiction.

Genetic polymorphisms of alcohol dehydrogense-1B and aldehyde dehydrogenase-2, alcohol flushing, mean corpuscular volume, and aerodigestive tract neoplasia in Japanese drinkers

Genetic polymorphisms of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) modulate exposure levels to ethanol/acetaldehyde. Endoscopic screening of 6,014 Japanese alcoholics yielded high detection rates of esophageal squamous cell carcinoma (SCC; 4.1%) and head and neck SCC (1.0%). The risks of upper aerodigestive tract SCC/dysplasia, especially of multiple SCC/dysplasia, were increased in a multiplicative fashion by the presence of a combination of slow-metabolizing ADH1B*1/*1 and inactive heterozygous ALDH2*1/*2 because of prolonged exposure to higher concentrations of ethanol/acetaldehyde. A questionnaire asking about current and past facial flushing after drinking a glass (≈180 mL) of beer is a reliable tool for detecting the presence of inactive ALDH2. We invented a health-risk appraisal (HRA) model including the flushing questionnaire and drinking, smoking, and dietary habits. Esophageal SCC was detected at a high rate by endoscopic mass-screening in high HRA score persons. A total of 5.0% of 4,879 alcoholics had a history of (4.0%) or newly diagnosed (1.0%) gastric cancer. Their high frequency of a history of gastric cancer is partly explained by gastrectomy being a risk factor for alcoholism because of altered ethanol metabolism, e.g., by blood ethanol level overshooting. The combination of H. pylori-associated atrophic gastritis and ALDH2*1/*2 showed the greatest risk of gastric cancer in alcoholics. High detection rates of advanced colorectal adenoma/carcinoma were found in alcoholics, 15.7% of 744 immunochemical fecal occult blood test (IFOBT)-negative alcoholics and 31.5% of the 393 IFOBT-positive alcoholics. Macrocytosis with an MCV≥106 fl increased the risk of neoplasia in the entire aerodigestive tract of alcoholics, suggesting that poor nutrition as well as ethanol/acetaldehyde exposure plays an important role in neoplasia.

Ethanol pharmacokinetics in neonates and infants

Introduction

Ethanol has been used for years in neonatal and infant liquid medications, yet the pharmacokinetics, pharmacodynamics, and safety of ethanol in this vulnerable population have not been well characterized. The purpose of this review is to raise awareness of ethanol use as an excipient in neonatal and infant medications and to provide insight, based on the available evidence, into clearance rates of ethanol in babies. We also discuss ethanol pharmacokinetics in adults, theoretical pharmacokinetic changes in neonates and infants as it may apply to ethanol disposition, and case reports involving ethanol exposure in neonates and infants.

Materials and methods

This study was a narrative review in which relevant papers were selected using databases and scientific search engines such as PubMed with the key words ethanol, infant, and newborninfant.

Results

It remains unclear what ethanol exposure is safe for neonates and infants. The Food and Drug Administration and American Academy of Pediatrics have both taken action, by either setting limits of ethanol content in over-the-counter medications or by recommending restricted exposure to ethanol-containing pediatric formulations.

Conclusions

Until the short- and long-term health effects of chronic ethanol administration can be further characterized, ethanol-containing medications should be used with caution.

Alcohol metabolism is not affected by sleeve gastrectomy

INTRODUCTION

It has been published that patients who underwent gastric bypass surgery have impaired alcohol metabolism, predisposing them to higher rates of intoxication and DUI arrests. Yet the impact of laparoscopic sleeve gastrectomy (LSG) on alcohol metabolism and in particular the long-term effects are still unclear. We hypothesized that LSG does not alter alcohol metabolism.

METHODS

A prospective cohort study of patients undergoing LSG was evaluated. Blood alcohol concentration (BAC) was extrapolated using a Breathalyzer(®). Alcohol metabolism was evaluated by determining BAC every 5 min after a single dose of alcohol (5 oz. glass of 14% v/v Malbec wine), until BAC was equal to zero. Subjects were queried about alcohol intoxication symptoms. All parameters were obtained and analyzed preoperatively and at 3 and 12 months postoperatively.

RESULTS

Our study consisted of 10 patients (9 female) with a mean age of 46.6 ± 2.2 years and BMI of 43.5 ± 2.2 kg/m(2). The mean percentage excess weight loss was 39.5 ± 3.3 at 3 months and 55.6 ± 4.4 at 12 months. Peak BAC at 20 min was not different at 3 months (0.068 ± 0.007, p = 0.77) or at 12 months (0.047 ± 0.008, p = 0.19) when compared to the preoperative assessment (0.059 ± 0.014). In addition, the time to BAC equal to zero was not significantly different between baseline and the follow-up values (preoperative: 70 ± 9 min, 3 months: 95 ± 18 min, and 12 months: 57 ± 8 min, (p > 0.05). Symptoms of intoxication were not significantly different in patients before and after surgery.

CONCLUSIONS

Our study suggests that LSG does not alter alcohol metabolism. Patients who undergo LSG do not have higher levels of intoxication following alcohol consumption and are therefore not prone to higher rates of DUI charges than the general public, in contrast to that previously reported following in patients who undergo gastric bypass surgery.

Ethanol metabolism and its effects on the intestinal epithelial barrier

Ethanol is widely consumed and is associated with an increasing global health burden. Several reviews have addressed the effects of ethanol and its oxidative metabolite, acetaldehyde, on the gastrointestinal (GI) tract, focusing on carcinogenic effects or alcoholic liver disease. However, both the oxidative and the nonoxidative metabolites of ethanol can affect the epithelial barrier of the small and large intestines, thereby contributing to GI and liver diseases. This review outlines the possible mechanisms of ethanol metabolism as well as the effects of ethanol and its metabolites on the intestinal barrier. Limited studies in humans and supporting in vitro data have indicated that ethanol as well as mainly acetaldehyde can increase small intestinal permeability. Limited evidence also points to increased colon permeability following exposure to ethanol or acetaldehyde. In vitro studies have provided several mechanisms for disruption of the epithelial barrier, including activation of different cell-signaling pathways, oxidative stress, and remodeling of the cytoskeleton. Modulation via intestinal microbiota, however, should also be considered. In conclusion, ethanol and its metabolites may act additively or even synergistically in vivo. Therefore, in vivo studies investigating the effects of ethanol and its byproducts on permeability of the small and large intestines are warranted.

Possible risk factors for increased suicide following bariatric surgery

OBJECTIVE

There is a growing research literature suggesting that there may be elevated risk of suicide following bariatric surgery. Most of the data reported thus far has been cross-sectional and observational, and very little is known about the possible specific causal variables involved.

DESIGN AND METHODS

The purpose of this report is to review this literature and to review possible risk factors for increased suicidal risk following bariatric surgery, to delineate future research directions.

RESULTS

First a variety of medical, biological, and genetic factors, including the persistence or recurrence of medical comorbidities after bariatric surgery, the disinhibition and impulsivity secondary to changes in the absorption of alcohol, hypoglycemia, as well as pharmacokinetic changes that may affect the absorption of various medications including antidepressant medications are reviewed. Also reviewed are possible mediating factors involving changes in various peptidergic systems such as GLP-1 and Ghrelin. A number of psychosocial issues that might be involved are discussed, including lack of improvement in quality of life after surgery, continued or recurrent physical mobility restrictions, persistence or recurrence of sexual dysfunction and relationship problems, low self-esteem, and a history of child maltreatment. Inadequate weight loss or weight regain are also discussed.

CONCLUSIONS

A number of possible contributing factors have been identified. Possible theoretical models involved and directions for research are suggested.

Trends in gastrectomy and ADH1B and ALDH2 genotypes in Japanese alcoholic men and their gene-gastrectomy, gene-gene and gene-age interactions for risk of alcoholism

AIMS

The life-time drinking profiles of Japanese alcoholics have shown that gastrectomy increases susceptibility to alcoholism. We investigated the trends in gastrectomy and alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) genotypes and their interactions in alcoholics.

METHODS

This survey was conducted on 4879 Japanese alcoholic men 40 years of age or older who underwent routine gastrointestinal endoscopic screening during the period 1996-2010. ADH1B/ALDH2 genotyping was performed in 3702 patients.

RESULTS

A history of gastrectomy was found in 508 (10.4%) patients. The reason for the gastrectomy was peptic ulcer in 317 patients and gastric cancer in 187 patients. The frequency of gastrectomy had gradually decreased from 13.3% in 1996-2000 to 10.5% in 2001-2005 and to 7.8% in 2006-2010 (P < 0.0001). ADH1B*1/*1 was less frequent in the gastrectomy group than in the non-gastrectomy group (age-adjusted prevalence: 20.4 vs. 27.6%, P = 0.006). ALDH2 genotype distribution did not differ between the two groups. The frequency of inactive ALDH2*1/*2 heterozygotes increased slightly from 13.0% in 1996-2000 to 14.0% in 2001-2005 and to 15.4% in 2006-2010 (P < 0.08). Two alcoholism-susceptibility genotypes, ADH1B*1/*1 and ALDH2*1/*1, modestly but significantly tended not to occur in the same individual (P = 0.026). The frequency of ADH1B*1/*1 decreased with ascending age groups.

CONCLUSIONS

The high frequency of history of gastrectomy suggested that gastrectomy is still a risk factor for alcoholism, although the percentage decreased during the period. The alcoholism-susceptibility genotype ADH1B*1/*1 was less frequent in the gastrectomy group, suggesting a competitive gene-gastrectomy interaction for alcoholism. A gene-gene interaction and gene-age interactions regarding the ADH1B genotype were observed.

Metabolism of ethanol and associated hepatotoxicity

Over the last three decades, direct hepatotoxic effects of ethanol were established, some of which were linked to redox changes produced by NADH generated via the alcohol dehydrogenase (ADH) pathway and shown to affect the metabolism of lipids, carbohydrates, proteins, and purines. It was also determined that ethanol can be oxidized by a microsomal ethanol oxidizing system (MEOS) involving a specific cytochrome P-450; this newly discovered ethanol-inducible cytochrome P-450 (P-450 IIEi) contributes to ethanol metabolism, tolerance, energy wastage (with associated weight loss), and the selective hepatic perivenular toxicity of various xenobiotics. Their activation by P-450IIEi now provides an understanding of the increased susceptibility of the heavy drinker to the toxicity of industrial solvents, anaesthetic agents, commonly prescribed drugs, over-the-counter analgesics, and chemical carcinogens. P-450 induction also explains depletion (and toxicity) of nutritional factors such as vitamin A. As a consequence, treatment with vitamin A and other nutritional factors is beneficial, but must take into account a narrowed therapeutic window in alcoholics who have increased needs for nutrients and also display an enhanced susceptibility to some of their adverse effects. Acetaldehyde (the metabolite produced from ethanol by either ADH or MEOS) impairs hepatic oxygen utilization and forms protein adducts, resulting in antibody production, enzyme inactivation, and decreased DNA repair. It also stimulates collagen production by the vitamin A storing cells (lipocytes) and myofibroblasts, and causes glutathione depletion. Supplementation with S-adenosyl-L-methionine partly corrects the depletion and associated mitochondrial injury, whereas administration of polyunsaturated lecithin opposes the fibrosis. Thus, at the cellular level, the classic dichotomy between the nutritional and toxic effects of ethanol has now been bridged. The understanding of how the ensuing injury eventually results in irreversible scarring or cirrhosis may provide us with improved modalities for treatment and prevention.

Effects of lipase inhibition on gastric emptying and alcohol absorption in healthy subjects

The rate of alcohol absorption is dependent on gastric emptying (GE). As the slowing of GE by fat is dependent on lipolysis, orlistat may increase the rise in blood alcohol when alcohol is consumed with, or after, fat. The aim of the study was to evaluate the effects of orlistat on GE and blood alcohol after an alcohol-containing drink following a fat 'preload', in healthy subjects. Ten healthy males consumed 120 ml cream with or without 120 mg orlistat, 30 min before an alcohol-containing drink labelled with 20 MBq [(99 m)Tc]sulfur colloid on 2 d. GE, plasma alcohol and blood glucose were measured. GE was slightly faster with orlistat (P<0.05) compared with control. Plasma alcohol at 15 min was slightly higher with orlistat (0.034 (SEM 0.006) g/100 ml) v. control (0.029 (SEM 0.005) g/100 ml) (P<0.05), but there was no effect on the area under the curve 0-240 min. The increase in blood glucose was greater with orlistat, for example, at 15 min (1.07 (SEM 0.2) mmol/l) v. control (0.75 (SEM 0.2) mmol/l) (P=0.05). The rise in blood glucose and plasma alcohol were related (for example, at 15 min r 0.49; P=0.03). In conclusion, lipase inhibition accelerates GE of an alcohol-containing drink following a fat 'preload' with a minor increase in the initial rise in plasma alcohol.

Functional Assessment of Human Alcohol Dehydrogenase Family in Ethanol Metabolism: Significance of First-Pass Metabolism

BACKGROUND

Alcohol dehydrogenase (ADH) is the principal enzyme responsible for ethanol metabolism in mammals. Human ADH constitutes a unique complex enzyme family with no equivalent counterpart in experimental rodents. This study was undertaken to quantitatively assess relative contributions of human ADH isozymes and allozymes to hepatic versus gastric metabolism of ethanol in the context of the entire family.

METHODS

Kinetic parameters for ethanol oxidation for recombinant human class I ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, and ADH1C2; class II ADH2; class III ADH3; and class IV ADH4 were determined in 0.1 M sodium phosphate at pH 7.5 over a wide range of substrate concentrations in the presence of 0.5 mM NAD+. The composite numerical formulations for organ steady-state ethanol clearance were established by summing up the kinetic equations of constituent isozymes/allozymes with the assessed contents in livers and gastric mucosae with different genotypes.

RESULTS

In ADH1B*1 individuals, ADH1B1 and ADH1C allozymes were found to be the major contributors to hepatic-alcohol clearance; ADH2 made a significant contribution only at high ethanol levels (> 20 mM). ADH1B2 was the major hepatic contributor in ADH1B*2 individuals. ADH1C allozymes were the major contributor at low ethanol (< 2 mM), whereas ADH1B3 the major form at higher levels (> 10 mM) in ADH1B*3 individuals. For gastric mucosal-alcohol clearance, the relative contributions of ADH1C allozymes and ADH4 were converse as ethanol concentration increased. It was assessed that livers with ADH1B*1 may eliminate approximately 95% or more of single-passed ethanol as inflow sinusoidal alcohol reaches approximately 1 mM and that stomachs with different ADH1C genotypes may remove 20% to 30% of single-passed alcohol at the similar level in mucosal cells.

CONCLUSIONS

This work provides just a model, but a strong one, for quantitative assessments of ethanol metabolism in the human liver and stomach. The results indicate that the hepatic-alcohol clearance of ADH1B*2 individuals is higher than that of the ADH1B*1 and those of the ADH1B*3 versus the ADH1B*1 vary depending on sinusoidal ethanol levels. The maximal capacity for potential alcohol first-pass metabolism in the liver is greater than in the stomach.

Effect of alcohol consumption on the gut

Both acute and chronic alcohol consumption have severe effects on the structure and function of the entire gastrointestinal tract (GIT) which result in a vicious cycle. The healthy person who begins to drink heavily, first experiences the toxic effects of high concentrations of ethanol. Mucosal damage compromises the basic functions of the GIT. Suppression of the gastrointestinal immune system and increased transport of toxins across the mucosa result in increased susceptibility to infections. Inhibition of digestion, absorption and secretion cause diarrhea and reduce the transfer of nutrients to the rest of the body. As the individual becomes more dependent on alcohol, the functional reserve and regenerative capacity of the GIT are overwhelmed and malnutrition increases. The rate of progression of this cycle depends on several factors including nutritional intake. Whilst the clinical effects of alcohol are well recognized, more research is required to fully elucidate the underlying mechanisms.

Association of laryngeal cancer with previous gastric resection

OBJECTIVE

To investigate the association between gastric surgery and cancer of the larynx.

SUMMARY BACKGROUND DATA

Biliary reflux is frequent after gastric surgery and may reach the proximal segment of the esophagus and the larynx. It is possible that duodenal content (consisting in bile acids, trypsin), together with pepsin and acid residues when gastric resection is partial, may cause harmful action on the multistratified epithelium of the larynx.

METHODS

A retrospective case-control study on subjects admitted between January 1987 and May 2002 in the same hospital in Rome was carried out. The study included 828 consecutive patients with laryngeal cancer (cases) and 825 controls with acute myocardial infarction. Controls were randomly sampled out of a total of 10,000 and matched with cases for age, sex, and year of admission. Logistic regression models were used to assess the role of gastric resection in determining laryngeal cancer risk while controlling for potential confounding factors.

RESULTS

Previous gastrectomy was reported by 8.1% of cases and 1.8% of the controls (P < 0.0001). A 4-fold association emerged between gastric surgery and laryngeal cancer risk (adjusted OR = 4.3, 95% CI: 2.4-7.9). The risk appeared strongly increased 20 years after surgery (OR = 14.8, 95% CI: 3.4-64.6). Heavy alcohol drinking (OR = 2.5, 95% CI: 1.8-3.5), smoking (OR = 4.7, 95% CI: 3.3-6.7), and blue-collar occupation (OR = 4.6, 95% CI: 3.2-6.7) were all independently associated with the risk of laryngeal cancer.

CONCLUSIONS

Previous gastric surgery is associated with an increased risk of laryngeal cancer. A periodic laryngeal examination should be considered in long-term follow-up of patients with gastric resection.

First-pass metabolism of ethanol in human beings: effect of intravenous infusion of fructose

Intravenous infusion of fructose has been shown to enhance reduced form of nicotinamide adenine dinucleotide reoxidation and, thereby, to enhance the metabolism of ethanol. In the current study, the effect of fructose infusion on first-pass metabolism of ethanol was studied in human volunteers. A significantly higher first-pass metabolism of ethanol was obtained after administration of fructose in comparison with findings for control experiments with an equimolar dose of glucose. Because fructose is metabolized predominantly in the liver and can be presumed to have virtually no effects in the stomach, results of the current study support the assumption that only a negligible part of first-pass metabolism of ethanol occurs in the stomach.

Expression, localization and potential physiological significance of alcohol dehydrogenase in the gastrointestinal tract

ADH1 and ADH4 are the major alcohol dehydrogenases (ADH) in ethanol and retinol oxidation. ADH activity and protein expression were investigated in rat gastrointestinal tissue homogenates by enzymatic and Western blot analyses. In addition, sections of adult rat gastrointestinal tract were examined by in situ hybridization and immunohistochemistry. ADH1 and ADH4 were detected along the whole tract, changing their localization and relative content as a function of the area studied. While ADH4 was more abundant in the upper (esophagus and stomach) and lower (colorectal) regions, ADH1 was predominant in the intestine but also present in stomach. Both enzymes were detected in mucosa but, in general, ADH4 was found in outer cell layers, lining the lumen, while ADH1 was detected in the inner cell layers. Of interest were the sharp discontinuities in the expression found in the pyloric region (ADH1) and the gastroduodenal junction (ADH4), reflecting functional changes. The precise localization of ADH in the gut reveals the cell types where active alcohol oxidation occurs during ethanol ingestion, providing a molecular basis for the gastrointestinal alcohol pathology. Localization of ADH, acting as retinol dehydrogenase/retinal reductase, also indicates sites of active retinoid metabolism in the gut, essential for mucosa function and vitamin A absorption.

Alcohol metabolism: role in toxicity and carcinogenesis

This article contains the proceedings of a symposium at the 2002 RSA Meeting in San Francisco, organized and co-chaired by Thomas M. Badger, Paul Shih-Jiun Yin, and Helmut Seitz. The presentations were (1) First-pass metabolism of ethanol: Basic and clinical aspects, by Charles Lieber; (2) Intracellular CYP2E1 transport, oxidative stress, cytokine release, and ALD, by Magnus Ingelman-Sundberg; (3) Pulsatile ethanol metabolism in intragastric infusion models: Potential role in toxic outcomes, by Thomas M. Badger and Martin J.J. Ronis; (4) Free radicals, adducts, and autoantibodies resulting from ethanol metabolism: Role in ethanol-associated toxicity, by Emanuele Albano; and (5) Gastrointestinal metabolism of ethanol and its possible role in carcinogenesis, by Helmut Seitz.

PKQuest: measurement of intestinal absorption and first pass metabolism - application to human ethanol pharmacokinetics

BACKGROUND

PKQuest, a new physiologically based pharmacokinetic (PBPK) program, is applied to human ethanol data. The classical definition of first pass metabolism (FPM) based on the differences in the area under the curve (AUC) for identical intravenous and oral doses is invalid if the metabolism is non-linear (e.g. ethanol). Uncertainties in the measurement of FPM have led to controversy about the magnitude of gastric alcohol metabolism. PKQuest implements a new, rigorous definition of FPM based on finding the equivalent intravenous input function that would produce a blood time course identical to that observed for the oral intake. This input function equals the peripheral availability (PA) and the FPM is defined by: FPM = Total oral dose - PA. PKQuest also provides a quantitative measurement of the time course of intestinal absorption.

METHODS

PKQuest was applied to previously published ethanol pharmacokinetic data.

RESULTS

The rate of ethanol absorption is primarily limited by the rate of gastric emptying. For oral ethanol with a meal: absorption is slow (Tilde; 3 hours) and the fractional PKQuest FPM was 36% (0.15 gm/Kg dose) and 7% (0.3 gm/Kg). In contrast, fasting oral ethanol absorption is fast (Tilde; 50 minutes) and FPM is small.

CONCLUSIONS

The standard AUC and one compartment methods significantly overestimate the FPM. Gastric ethanol metabolism is not significant. Ingestion of a coincident meal with the ethanol can reduce the peak blood level by about 4 fold at low doses. PKQuest and all the examples are freely available on the web at www.pkquest.com.

Gender differences in alcohol metabolism. Physiological responses to ethanol

A gender difference in alcohol pharmacokinetics has been suggested to explain why women are more vulnerable to ethanol's toxic effects. The results of animal experiments suggest that females exhibit higher alcohol metabolic rates than males as a result of hormonal differences. Experimental results examining gender differences in human alcohol metabolism have been inconsistent; the diversity of experimental protocols and variety of pharmacokinetic parameters reported have made comparisons of these studies very difficult. Variability in alcohol metabolic rate between individuals of the same sex is often significant, preventing an assessment of gender differences in some studies. This chapter attempts to summarize the findings of studies from the last decade that examined the role of gender and sex hormone differences on ethanol metabolism in men and women. The role of body composition, genetic factors, gastric and hepatic alcohol dehydrogenase, and gastric absorption in creating gender differences in alcohol metabolism is discussed. Suggestions are offered that may result in better cross-study comparisons and more consistent experimental results.

ALCOHOL: its metabolism and interaction with nutrients

In the past, alcoholic liver disease was attributed exclusively to dietary deficiencies, but experimental and judicious clinical studies have now established alcohol's hepatotoxicity. Despite an adequate diet, it can contribute to the entire spectrum of liver diseases, mainly by generating oxidative stress through its microsomal metabolism via cytochrome P4502E1 (CYP2E1). It also interferes with nutrient activation, resulting in changes in nutritional requirements. This is exemplified by methionine, one of the essential amino acids for humans, which needs to be activated to S-adenosylmethionine (SAMe), a process impaired by liver disease. Thus, SAMe rather than methionine is the compound that must be supplemented in the presence of significant liver disease. In baboons, SAMe attenuated mitochondrial lesions and replenished glutathione; it also significantly reduced mortality in patients with Child A or B cirrhosis. Similarly, decreased phosphatidylethanolamine methyltransferase activity is associated with alcoholic liver disease, resulting in phosphatidylcholine depletion and serious consequences for the integrity of membranes. This can be offset by polyenylphosphatidylcholine (PPC), a mixture of polyunsaturated phosphatidylcholines comprising dilinoleoylphosphatidylcholine (DLPC), which has high bioavailability. PPC (and DLPC) opposes major toxic effects of alcohol, with down-regulation of CYP2E1 and reduction of oxidative stress, deactivation of hepatic stellate cells, and increased collagenase activity, which in baboons, results in prevention of ethanol-induced septal fibrosis and cirrhosis. Corresponding clinical trials are ongoing.

Contribution of gastric oxidation to ethanol first-pass metabolism in baboons

BACKGROUND

A portion of ingested alcohol does not reach the systemic blood, undergoing a first-pass metabolism (FPM) during gastric and hepatic circulation.

METHODS

To determine whether the stomach can metabolize sufficient ethanol to account for the FPM, and to what extent gastric alcohol dehydrogenase (ADH) activity is responsible, the hepatic vein, the portal vein, and the aorta were cannulated nonocclusively in baboons to measure the conversion of ethanol to acetate in vivo. 14C-ethanol (300 mg/kg as a 15% solution) was given intragastrically (IG) whereas 3H-acetate was continuously infused intravenously (IV). 14C-acetate was measured after exhaustive evaporation of ethanol. Simultaneous sampling of hepatic venous, portal and arterial blood was carried out for 3 hr, at the end of which the same alcohol dose was given IV to calculate the Michaelis-Menten parameters of elimination.

RESULTS

Analysis of the IV and IG ethanol curves revealed a FPM of 94+/-11 mg/kg (31% of dose). The portal-arterial differences were negative for 3H-acetate (indicating net extraction) and positive for 14C-ethanol and 14C-acetate (indicating net output). Portal acetate production (extraction plus net output multiplied by the portal plasma flow) increased with time and accounted, over the first 3 hr (82+/-13 mg/kg), for 87% of the FPM. Alcohol oxidation by gastric ADH activity (28.7+/-7.2 mg/kg) accounted for only 31% of the FPM.

CONCLUSIONS

The in vivo oxidation of ethanol to acetate in the upper digestive tract accounts for the FPM of ethanol and is mediated, at least in part, by ADH activity.

Appropriate use and misuse of blood concentration measurements to quantitate first-pass metabolism

First-pass metabolism commonly is determined from the difference in the area under the blood concentration time curve (AUC) that is observed with oral versus intravenous administration of a compound. It is not fully appreciated that this technique serves as an accurate indicator of first-pass metabolism only when the clearance of the compound under consideration is first order (unsaturated) throughout the range of blood concentrations observed in the study. For example, multiple publications continue to mistakenly use AUC measurements to assess the first-pass metabolism of ethanol, a compound cleared primarily via zero-order kinetics. This report briefly reviews the physiologic basis of measurements of first-pass metabolism, demonstrates the errors that result from application of this technique when clearance is not first order, and, using ethanol as an example, describes a technique that can be used to measure first-pass metabolism when clearance deviates from first order.

A comparison of the bioavailabilities of oral and intravenous ethanol in healthy male volunteers

OBJECTIVES

Ethanol (EtOH), the antidote for methanol and ethylene glycol, is administered by the oral (PO) and intravenous (IV) routes. Serum concentrations (SCs) of 100 mg/dL or more are targeted for clinical effect. This study was completed to validate the assumption that there are minimal differences in SC achieved between these two routes.

METHODS

Twenty healthy male volunteers were randomized to receive either PO or IV EtOH. Subjects abstained from EtOH for 48 hours before each phase. After a seven-day washout period, the subjects crossed over to the other group. Inclusion criteria were no history of medical problems, age between 21 and 40 years, and actual body weight within 10% of ideal weight. Baseline EtOH SCs were obtained before participation in each phase. Two hours after a standard breakfast, the subjects received 700 mg/kg of PO or IV EtOH. PO EtOH was administered as a 20% solution in juice over 10 minutes. IV EtOH, controlled by an infusion pump, was administered as a 10% solution over 30 minutes. Blood was drawn for EtOH SCs at 45, 75, 105, 135, 165, 225, 285, and 345 minutes after start of the dose.

RESULTS

All initial EtOH SCs were 0. EtOH SCs were higher after IV administration. Mean peak SC was 103.6 mg/dL after IV administration and 71.3 mg/dL after PO administration (p<0.0001). Mean time to peak was 46.5 minutes after IV administration and 103.5 minutes after PO administration (p<0.0001). Total area under the curve was 17,440 min-mg/dL after IV administration and 13,875 min-mg/dL after PO administration (p<0.003). The order of treatments did not affect results (p>0.1).

CONCLUSION

Significant differences exist between the SCs of EtOH as well as the times to peak SC after PO and IV administrations.

Is there an interaction between H2-antagonists and alcohol?

H2-antagonists are commonly prescribed drugs and alcohol use is widespread in the community. Any possible interaction may be important because of the frequent co-administration of both drugs and the potential for unexpected impairment of pyschomotor function, in particular, driving skills. Hepatic ADH is the major site of alcohol metabolism. ADH is also found in the stomach, but it is uncertain whether gastric ADH is able to metabolise a significant amount of alcohol in vivo. Significant first-pass metabolism can be demonstrated at lower doses of alcohol, and if alcohol is given after meals. Varying degrees of extraction of alcohol from the portal circulation probably explains the data regarding first pass metabolism rather than gastric metabolism by gastric ADH. H2-receptor antagonists inhibit gastric ADH activity to a variable extent. If gastric metabolism of alcohol is negligible then this inhibition has no relevance. Given the uncertainty regarding a mechanism of interaction, only carefully conducted studies in controlled environments will answer the question. The large inter-subject variability of alcohol absorption means that any study which seeks to determine the effect of an H2-receptor antagonist on ethanol metabolism must have sufficient numbers. A cross-over design, with each subject acting as his own control, is preferable to avoid ascribing an effect to treatment rather than to chance. The alcohol dosing studies are reviewed and the results summarised according to dose of alcohol given. At a dose of 0.15 g/kg of alcohol, four commonly used H2-antagonists may cause a small increase in blood alcohol concentrations in certain conditions. This absolute increase is very small. The magnitude of effect is far less than the effect of taking a meal before alcohol. At doses of 0.3 g/kg and above the majority of evidence favours no interaction between H2-antagonists and alcohol. There is no interaction at doses that would be expected to impair psychomotor skills (above 25 mg/dl). There remains a question regarding the cumulative effect of repeated small doses of alcohol and further studies are required. The relationship between ethanol absorption and gastric emptying raises the possibility that the effects of H2-receptor antagonists observed at very low doses of alcohol may be due to the acceleration of gastric emptying by these drugs. This is an attractive hypothesis that explains many aspects of the debate, but studies of the effect of H2-antagonists on gastric emptying have been conflicting.

Medical risks for women who drink alcohol

OBJECTIVE

To summarize for clinicians recent epidemiologic evidence regarding medical risks of alcohol use for women.

METHODS

MEDLINE and PsychINFO, 1990 through 1996, were searched using key words "women" or "woman," and "alcohol." MEDLINE was also searched for other specific topics and authors from 1980 through 1996. Data were extracted and reviewed regarding levels of alcohol consumption associated with mortality, cardiovascular disease, alcohol-related liver disease, injury, osteoporosis, neurologic symptoms, psychiatric comorbidity, fetal alcohol syndrome, spontaneous abortion, infertility, menstrual symptoms, breast cancer, and gynecologic malignancies. Gender-specific data from cohort studies of general population or large clinical samples are primarily reviewed.

MAIN RESULTS

Women develop many alcohol-related medical problems at lower levels of consumption than men, probably reflecting women's lower total body water, gender differences in alcohol metabolism, and effects of alcohol on postmenopausal estrogen levels. Mortality and breast cancer are increased in women who report drinking more than two drinks daily. Higher levels of alcohol consumption by women are associated with increased menstrual symptoms, hypertension, and stroke. Women who drink heavily also appear to have increased infertility and spontaneous abortion. Adverse fetal effects occur after variable amounts of alcohol consumption, making any alcohol use during pregnancy potentially harmful.

CONCLUSIONS

In general, advising nonpregnant women who drink alcohol to have fewer than two drinks daily is strongly supported by the epidemiologic literature, although specific recommendations for a particular woman should depend on her medical history and risk factors.

Gastrointestinal alcohol dehydrogenase

Alcohol dehydrogenase (ADH) consists of a family of isozymes that convert alcohols to their corresponding aldehydes using NAD+ as a cofactor. The metabolism of ethanol by gastrointestinal ADH isozymes results in the production of acetaldehyde, a highly toxic compound that binds to cellular protein and DNA if not further metabolized to acetate by acetaldehyde dehydrogenase isozymes. Acetaldehyde seems to be involved in ethanol-associated cocarcinogenesis. The metabolism of retinol and the generation of retinoic acid is a function of class I and class IV ADH, and its inhibition by alcohol may lead to an alteration of epithelial cell differentiation and cell growth and may also be involved in ethanol-associated gastrointestinal cocarcinogenesis.

Inhibition of bacteriocolonic pathway for ethanol oxidation by ciprofloxacin in rats

Many colonic bacteria possess marked alcohol dehydrogenase (ADH) activity and are capable of oxidizing ethanol to acetaldehyde both in vitro and in vivo. We have recently shown that part of ingested ethanol is metabolized to acetaldehyde in the colon during normal alcohol metabolism. To assess the contribution of this bacteriocolonic pathway for ethanol oxidation to total ethanol metabolism, the elimination rate of ethanol, faecal aerobic flora and faecal ADH activity were determined in rats before and after the treatment with ciprofloxacin (200 mg/kg/day) for four days. Ciprofloxacin treatment decreased ethanol elimination rate from 310+/-9 to 282+/-13 mg/kg/h (mean+/-SE; p<0.02), markedly reduced faecal aerobic flora, and also lowered faecal ADH activity from 63+/-17 to 17+/-7 nmol/min/mg faeces (p<0.05). Neither hepatic ADH nor microsomal ethanol oxidizing system activities were affected by the ciprofloxacin treatment. On the contrary, an acute intraperitoneal dose of ciprofloxacin had no effect on the rate of ethanol elimination. These results support the significant role of the bacteriocolonic pathway in total ethanol elimination, and open a new, microbiological, perspective for studies on ethanol metabolism and pathogenesis of alcohol related organ damages.