Pharmacokinetic interactions between alcohol and other drugs

Alcohol Consumption Is a Coping Mechanism for Male Patients with Severe Anxiety Disorders Treated with Antidepressants Monotherapy

Background: Anxiety disorders are prevalent mental health conditions often accompanied by various comorbidities. The association between anxiety and liver disease, as well as fluctuations in blood sugar levels, highlights the importance of carefully evaluating patients with anxiety undergoing antidepressant therapy. The aim of this study was to conduct a comparative assessment of liver function and blood glucose levels in patients diagnosed with anxiety disorders while considering potential gender-specific differences. Methods: An analysis was conducted over a 24-month period. This study included 88 patients diagnosed with anxiety disorders, with symptoms severe enough to require hospitalization, aged 18 or older, undergoing antidepressant monotherapy, without any additional pathologies. Liver enzymes (AST, ALT, GGT), AST/ALT ratio, and blood glucose levels were measured and compared. Results: While no significant differences were found between antidepressant classes, increased GGT levels were observed in men older than 40 years compared to women of the same age, suggesting that alcohol consumption may be a coping mechanism for anxiety. This gender difference was not observed among young patients. Conclusions: Early detection of alcohol consumption is essential in patients with anxiety disorders in order to prevent alcohol-related liver damage and to adjust the management of both conditions accordingly.

Age and Sex in the Development of Hepatic Encephalopathy: Role of Alcohol

Hepatic encephalopathy (HE) is a neurological condition linked to liver failure. Acute HE (Type A) occurs with acute liver failure, while chronic HE (Type C) is tied to cirrhosis and portal hypertension. HE treatments lag due to gaps in understanding its development by gender and age. We studied how sex and age impact HE and its severity with combined liver toxins. Our findings indicate that drug-induced (thioacetamide, TAA) brain edema was more severe in aged males than in young males or young/aged female rats. However, adding alcohol (ethanol, EtOH) worsens TAA's brain edema in both young and aged females, with females experiencing a more severe effect than males. These patterns also apply to Type A HE induced by azoxymethane (AZO) in mice. Similarly, TAA-induced behavioral deficits in Type C HE were milder in young and aged females than in males. Conversely, EtOH and TAA in young/aged males led to severe brain edema and fatality without noticeable behavioral changes. TAA metabolism was slower in aged males than in young or middle-aged rats. When TAA-treated aged male rats received EtOH, there was a slow and sustained plasma level of thioacetamide sulfoxide (TASO). This suggests that with EtOH, TAA-induced HE is more severe in aged males. TAA metabolism was similar in young, middle-aged, and aged female rats. However, with EtOH, young and aged females experience more severe drug-induced HE as compared to middle-aged adult rats. These findings strongly suggest that gender and age play a role in the severity of HE development and that the presence of one or more liver toxins may aggravate the severity of the disease progression.

Determinants of adverse reactions to first-line antitubercular medicines: a prospective cohort study

BACKGROUND

The success of tuberculosis treatment relies on patients adhering to their medication regimen consistently. However, adherence levels tend to decrease among patients who experience adverse drug reactions to antitubercular medications, leading to suboptimal treatment outcomes. Hence, this study aimed to examine the types, incidence rates, and severity of adverse reactions caused by first-line antitubercular drugs. Additionally, it aimed to identify factors associated with the development of these reactions. By doing so, the study aimed to facilitate the provision of personalized and effective treatment to patients, ultimately improving treatment outcomes.

METHODS

Newly diagnosed patients with active tuberculosis were monitored from the start of their treatment until the completion of therapy. Any adverse reactions to anti-TB drugs that they encountered were carefully recorded. The collected data were analyzed using appropriate statistical methods such as analysis of variance, Chi-squared test, Fisher's exact test, and independent t-tests. Logistic regression was employed to assess the association between adverse drug reactions and various socio-demographic and clinical factors of the patients, using odds ratios as a measure of association.

RESULTS

Among the 378 patients included in the study, 181 individuals (47.9%) reported experiencing at least one adverse drug reaction, with an incidence rate of 1.75 events per 100-person months. The majority of these reactions occurred during the intensive phase of treatment. The gastrointestinal tract was the most commonly affected system, followed by the nervous system and skin. Patients aged over 45 years (OR = 1.55, 95% CI 1.01-2.39, p = 0.046) and those with extrapulmonary tuberculosis (OR = 2.41, 95% CI 1.03-5.64) were more likely to develop gastrointestinal reactions. Female gender was a significant predictor of both skin (OR = 1.78, 95% CI 1.05-3.02, p = 0.032) and nervous system (OR = 1.65, 95% CI 1.07-2.55, p = 0.024) reactions. Additionally, alcohol use and HIV infection were identified as independent predictors of adverse drug reactions affecting all three systems.

CONCLUSION

Significant risk factors for developing antitubercular drug adverse reactions include alcohol consumption, cigarette smoking, being HIV positive, female gender and extrapulmonary tuberculosis.

The role of alcohol intake in the pharmacogenetics of treatment with clozapine

Clozapine (CLZ) is an atypical antipsychotic reserved for patients with refractory psychosis, but it is associated with a significant risk of severe adverse reactions (ADRs) that are potentiated with the concomitant use of alcohol. Additionally, pharmacogenetic studies have explored the influence of several genetic variants in CYP450, receptors and transporters involved in the interindividual response to CLZ. Herein, we systematically review the current multiomics knowledge behind the interaction between CLZ and alcohol intake, and how its concomitant use might modulate the pharmacogenetics. CYP1A2*1F, *1C and other alleles not yet discovered could support a precision medicine approach for better therapeutic effects and fewer CLZ ADRs. CLZ monitoring systems should be amended and include alcohol intake to protect patients from severe CLZ ADRs.

Alcohol-medication interactions: A systematic review and meta-analysis of placebo-controlled trials

Alcohol and other xenobiotics may limit the therapeutic effects of medications. We aimed at investigating alcohol-medication interactions (AMI) after the exclusion of confounding effects related to other xenobiotics. We performed a systematic review and meta-analysis of controlled studies comparing the effects induced by alcohol versus placebo on pharmacodynamic and/or pharmacokinetic parameters of approved medications. Certainty in the evidence of AMI was assessed when at least 3 independent studies and at least 200 participants were available. We included 107 articles (3097 participants): for diazepam, cannabis, opioids, and methylphenidate, we found significant AMI and enough data to assign the certainty of evidence. Alcohol consumption significantly increases the peak plasma concentration of diazepam (low certainty; almost 290 participants), cannabis (high certainty; almost 650 participants), opioids (low certainty; 560 participants), and methylphenidate (moderate certainty; 290 participants). For most medications, we found some AMI but not enough data to assign them the certainty grades; for some medications, we found no differences between alcohol and placebo in any outcomes evaluated. Our results add further evidence for interactions between alcohol and certain medications after the exclusion of confounding effects related to other xenobiotics. Physicians should advise patients who use these specific medications to avoid alcohol consumption. Further studies with appropriate control groups, enough female participants to investigate sex differences, and elderly population are needed to expand our knowledge in this field. Short phrases suitable for indexing terms.

The OATH Syndemic: opioids and other substances, aging, alcohol, tobacco, and HIV

PURPOSE OF REVIEW

Persons living with HIV (PLWH) are aging, continue to use alcohol and other substances, and experience age-associated adverse effects. We explore a new syndemic: OATH (opioids and other substances, aging, alcohol, tobacco, and HIV).

RECENT FINDINGS

Frailty and falls are important problems that affect the health status of PLWH who continue to use alcohol and other substances. HIV, alcohol and other substance use, and aging each contributes to inflammaging. Multimorbidity and polypharmacy are also important pathways as alcohol and other substances interact with prescribed medications resulting in adverse-drug interactions leading to potentially serious consequences. Social conditions including racism, poverty, sex bias, stress, and stigma contribute to the existence and persistence of this syndemic.

SUMMARY

Substance use, HIV, and aging are linked in a new syndemic (OATH) that drives age-related outcomes such as frailty and falls. We need to expand our understanding of the 'healthcare team' so that we include social and political advocates who can support necessary structural change. Treatment of substance use should be better incorporated into the management of HIV, including a focus on potential medication/substance interactions. Finally, we need to explore treatment of frailty rather than individual manifestations of frailty (e.g., atherosclerosis, neurodegeneration).

The microbiome and tuberculosis: state of the art, potential applications, and defining the clinical research agenda

The diverse microbial communities within our bodies produce metabolites that modulate host immune responses. Even the microbiome at distal sites has an important function in respiratory health. However, the clinical importance of the microbiome in tuberculosis, the biggest infectious cause of death worldwide, is only starting to be understood. Here, we critically review research on the microbiome's association with pulmonary tuberculosis. The research indicates five main points: (1) susceptibility to infection and progression to active tuberculosis is altered by gut Helicobacter co-infection, (2) aerosol Mycobacterium tuberculosis infection changes the gut microbiota, (3) oral anaerobes in the lung make metabolites that decrease pulmonary immunity and predict progression, (4) the increased susceptibility to reinfection of patients who have previously been treated for tuberculosis is likely due to the depletion of T-cell epitopes on commensal gut non-tuberculosis mycobacteria, and (5) the prolonged antibiotic treatment required for cure of tuberculosis has long-term detrimental effects on the microbiome. We highlight knowledge gaps, considerations for addressing these knowledge gaps, and describe potential targets for modifying the microbiome to control tuberculosis.

Alcohol Interaction with Cocaine, Methamphetamine, Opioids, Nicotine, Cannabis, and γ-Hydroxybutyric Acid

Millions of people around the world drink alcoholic beverages to cope with the stress of modern lifestyle. Although moderate alcohol drinking may have some relaxing and euphoric effects, uncontrolled drinking exacerbates the problems associated with alcohol abuse that are exploding in quantity and intensity in the United States and around the world. Recently, mixing of alcohol with other drugs of abuse (such as opioids, cocaine, methamphetamine, nicotine, cannabis, and γ-hydroxybutyric acid) and medications has become an emerging trend, exacerbating the public health concerns. Mixing of alcohol with other drugs may additively or synergistically augment the seriousness of the adverse effects such as the withdrawal symptoms, cardiovascular disorders, liver damage, reproductive abnormalities, and behavioral abnormalities. Despite the seriousness of the situation, possible mechanisms underlying the interactions is not yet understood. This has been one of the key hindrances in developing effective treatments. Therefore, the aim of this article is to review the consequences of alcohol's interaction with other drugs and decipher the underlying mechanisms.

Selective and sensitive quantification of the cytochrome P450 3A4 protein in human liver homogenates through multiple reaction monitoring mass spectrometry

This study aimed at establishing a sensitive multiple reaction monitoring-mass spectrometry (MRM-MS) method for the quantification of the drug metabolizing cytochrome P450 (CYP)3A4 enzyme in human liver homogenates. Liver samples were subjected to trypsin digestion. MRM-MS analyses were performed using three transitions optimized on one purified synthetic peptide unique to CYP3A4 and the standardizing protein, calnexin. Coefficient of variations for the precision and reproducibility of the MRM-MS measurement were also determined. The method was applied to liver samples from ten non-cholestatic donors and 34 cholestatic patients with primary biliary cholangitis (n = 12; PBC), primary sclerosing cholangitis (n = 10; PSC) or alcoholic liver disease (n = 12; ALD). The established method presented high sensitivity with limit of detection lower than 5 fmol, and was successfully applied for the absolute and relative quantification of CYP3A4 in both whole liver homogenate and microsomal fractions. When all groups were analyzed together, a significant correlation was observed for the MRM-based CYP3A4 protein quantification in homogenates and microsomes (r = 0.49, p < 0.001). No statistically significant difference was detected between CYP3A4 levels in PSC, PBC, ALD and control samples. Finally, the MRM-MS quantification of CYP3A4 in homogenates also correlated (r = 0.44; p < 0.05) with the level of enzyme activity in the same samples, as determined by measuring the chenodeoxycholic to hyocholic acid conversion. The established method provides a sensitive tool to evaluate the CYP3A4 protein in human liver homogenates from patients with normal or chronic/severe hepatic injury.

MEDICAL COMORBIDITY AND COMPLICATIONS

Like their peers in the general youth population, youth with chronic medical conditions (YCMC) are at risk for substance use, including nonmedical use of prescription medications. However, given dangerous disease-substance interactions, the stakes for detecting and intervening on substance use are perhaps even higher for YCMC. Given the risk for nonadherence with chronic disease management, it is incumbent on primary care providers, specialty providers, and behavioral health specialists to be vigilant in asking about substance use and providing brief counseling and referral to substance use treatment when appropriate.

Effects of idazoxan on alcohol pharmacokinetics and intoxication: a preliminary human laboratory study

BACKGROUND

Preliminary basic and human studies suggest that the α2 -adrenergic antagonist idazoxan may represent a novel medication for alcohol dependence. The goal of this study was to evaluate the safety and tolerability of the co-administration of idazoxan with alcohol and explore whether pharmacokinetics (PK) and biobehavioral mechanisms of idazoxan may alter alcohol's effects.

METHODS

This was a preliminary double-blind, single-dose, placebo-controlled, crossover, randomized human laboratory study. Ten social drinkers were dosed, in 2 different alcohol challenge studies (ACS), with a single oral dose of idazoxan (40 mg) or placebo, followed by a fixed alcohol dose 60 minutes later. Participants returned after a 1-week washout, and they were crossed over to the opposite medication condition.

RESULTS

There were no significant differences in adverse events between idazoxan and placebo. Moreover, during the ACS paradigm, 40 mg idazoxan was well tolerated with no significant autonomic effects compared to placebo; idazoxan reduced the peak blood alcohol level (p < 0.01) and time to peak (p < 0.05) compared to placebo. A PK/pharmacodynamic model aligned the biobehavioral effects, demonstrating that the co-administration of 40 mg idazoxan with alcohol decreased alcohol-related stimulation (p < 0.05) and increased alcohol-related sedation (p < 0.05).

CONCLUSIONS

This study supports the safety and tolerability of 40 mg idazoxan when co-administered with alcohol. Additionally, this study suggests that idazoxan may alter the biphasic effects of alcohol by decreasing stimulation and increasing sedation. These findings have implications for further investigation of using idazoxan as a probe to develop potential novel medications to treat alcoholic patients.

Prevalence and risk of potentially adverse drug interactions in the treatment of acute alcohol poisoning

ABSTRACT The aim of this paper is to determine the profile of acute alcohol poisoning and to estimate the risk of potentially adverse drug interactions (ADIs) in patients intoxicated by alcohol when attended in emergency care at hospital. A descriptive serial cross-sectional study was performed with 4,271 individuals intoxicated by alcohol, from January 2009 to July 2011. Possible correlations were measured by Pearson's chi-square test. The data show high consumption in the population, especially in males between 25 and 59 years. The main circumstances for poisoning were alcohol misuse (96.3%). After treatment complete recovery from the signs or symptoms of the poisoning was observed in 96.88% cases; and death in 0.70%. The demonstration of potential risk for ADIs in medical care included 300 medical records which contained a history of acute alcohol poisoning. Possible drug-drug interactions (44.2%) and drug-alcohol interactions (55.8%) were demonstrated in 60.60% of analyzed medical records. Among these cases, 3%, 92.4% and 4.6% were classified as mild, moderate and severe, respectively. The measurement of ADIs aims to prevent clinical complications in medical care for alcohol misuse disorders.

Alcohol Use as Risk Factors for Older Adults' Emergency Department Visits: A Latent Class Analysis

INTRODUCTION

Late middle-aged and older adults' share of emergency department (ED) visits is increasing more than other age groups. ED visits by individuals with substance-related problems are also increasing. This paper was intended to identify subgroups of individuals aged 50+ by their risk for ED visits by examining their health/mental health status and alcohol use patterns.

METHODS

Data came from the 2013 National Health Interview Survey's Sample Adult file (n=15,713). Following descriptive analysis of sample characteristics by alcohol use patterns, latent class analysis (LCA) modeling was fit using alcohol use pattern (lifetime abstainers, ex-drinkers, current infrequent/light/moderate drinkers, and current heavy drinkers), chronic health and mental health status, and past-year ED visits as indicators.

RESULTS

LCA identified a four-class model. All members of Class 1 (35% of the sample; lowest-risk group) were infrequent/light/moderate drinkers and exhibited the lowest probabilities of chronic health/mental health problems; Class 2 (21%; low-risk group) consisted entirely of lifetime abstainers and, despite being the oldest group, exhibited low probabilities of health/mental health problems; Class 3 (37%; moderate-risk group) was evenly divided between ex-drinkers and heavy drinkers; and Class 4 (7%; high-risk group) included all four groups of drinkers but more ex-drinkers. In addition, Class 4 had the highest probabilities of chronic health/mental problems, unhealthy behaviors, and repeat ED visits, with the highest proportion of Blacks and the lowest proportions of college graduates and employed persons, indicating significant roles of these risk factors.

CONCLUSION

Alcohol nonuse/use (and quantity of use) and chronic health conditions are significant contributors to varying levels of ED visit risk. Clinicians need to help heavy-drinking older adults reduce unhealthy alcohol consumption and help both heavy drinkers and ex-drinkers improve chronic illnesses self-management.

Associations of Mental Health and Substance Use Disorders With Presenting Problems and Outcomes in Older Adults' Emergency Department Visits

OBJECTIVES

The increasing prevalence of mental health and/or substance use disorders in older adults is a significant public health issue affecting their health, health care use, and health care outcomes. These disorders are especially prevalent in emergency department (ED) visits. This study examined the effect of mental health and substance use disorders on older adults' ED presenting problems and outcomes.

METHODS

Data were from the publicly available 2012 Nationwide Emergency Department Sample data set (unweighted n = 5,344,743 visits by the 65+ years age group). We used binary logistic regression analysis to test relationships between mental health and substance use disorders and suicide attempts, falls, and other injuries and multinomial logistic regression analysis to test relationships between the disorders and ED outcomes of death, hospital admission, transfer to institutional care, home health care, leaving against medical advice (AMA), or other or unknown destinations, as opposed to routine care.

RESULTS

Of ED visits by older adults, 5.1% involved anxiety disorders, 7.1% involved mood disorders, 10.45% involved delirium/dementia, 1.4% involved alcohol use disorders, and 0.6% involved drug use disorders; 0.2% were suicide-related, 12.0% involved falls, and 10.2% involved other injuries. Mental health and substance use disorders had large-to-medium effects on suicide attempts. Both dementia and delirium and alcohol use disorders had a small effect on falls. Drug use disorders had a small effect on other injuries. Anxiety disorder had a small effect on the risk of death in the ED or in the hospital, relative to routine care. Suicide attempts and drug use disorders had a medium effect on hospital admission. Suicide attempts had a large effect, delirium and dementia and other mental disorders had medium effects, and mood disorder had a small effect on the risk of transfer to another facility. Delirium and dementia, suicide attempts, and drug use disorders had small effects on the risk of discharge with home health care. Alcohol use disorders and drug use disorders had a small effect on the risk of leaving AMA. Finally, suicide attempts had a medium effect on the risk of other outcomes and unknown destinations.

CONCLUSIONS

Late-life mental health and substance use disorders are significant risk factors for both intentional self-harm and unintentional injuries that bring older adults to the ED and contribute to ED dispositions and outcomes that involve more intensive and longer-term health care services. The findings underscore the importance of detection and treatment of these disorders among older adults before they end up in the ED.

Interrelations between pain and alcohol: An integrative review

Pain and alcohol use are both highly prevalent in the general population, and pain-alcohol interrelations are of increasing empirical interest. Previous research has identified associations between pain and alcohol dependence, and the current review provides novel contributions to this emerging domain by incorporating studies that have tested relations between pain and low-to-moderate alcohol consumption, and by identifying potential psychosocial mechanisms of action. Specifically, we sought to integrate evidence of pain-alcohol relations derived from two directions of empirical inquiry (i.e., effects of alcohol on pain and effects of pain on alcohol use) across psychological, social, and biological literatures. We observed converging evidence that associations between alcohol consumption and pain may be curvilinear in nature. Whereas moderate alcohol use was observed to be associated with positive pain-related outcomes (e.g., greater quality of life), excessive drinking and alcohol use disorder appear to be associated with deleterious pain-related outcomes (e.g., greater pain severity). We also observed evidence that alcohol administration confers acute pain-inhibitory effects, and that situational pain may motivate alcohol consumption (e.g., drinking for pain-coping). Future research can inform theoretical and clinical applications through examination of temporal relations between pain and alcohol consumption, tests of hypothesized mechanisms, and the development of novel interventions.

Fatal kavalactone intoxication by suicidal intravenous injection

Kavalactones are a group of compounds found in kava, a beverage or extract prepared from the rhizome of the kava plant (Piper methysticum). Traditionally kava extracts have been used for their anxiolytic and sedative properties. Sales of kava extracts were severely restricted or prohibited in European countries in 2002 following several cases of serious hepatotoxicity. Here we report a case where high concentrations of kavalactones and ethanol were detected in post mortem femoral blood. An injection needle with a 10-mL syringe containing 7.5 mL of slightly yellowish liquid was found next to the victim, and there were numerous needle prints on both lower arms following the venous tracks. No evidence of other cause of death was found in the medico-legal investigation. The case was therefore classified as suicide using an injection of kavalactones intravenously together with alcohol poisoning.

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.

Wine, Food and Health

Wine has historically been associated with religious rights, used as a salubrious beverage, employed as a medication as well as a medicinal solvent, and consumed as a food accompaniment. It is the latter that is most intimately associated in the minds of most modern consumers. Despite this, there is little flavor commonality on which pairing could be based. The first section of the chapter examines this feature, and wine’s primary role as a palate cleanser and food condiment. The synergistic role of food and wine in suppressing each other’s least pleasant attributes is also explained. The final section deals with the latest evidence relating to the many beneficial health effects of moderate wine consumption, shortfalls in the data, headache induction, dental erosion, and conditions under which wine intake is contraindicated.

The Pharmacokinetics and Pharmacodynamics of Ximelagatran, an Oral Direct Thrombin Inhibitor, Are Unaffected by a Single Dose of Alcohol

Ximelagatran-a direct thrombin inhibitor rapidly converted to its active form, melagatran, after oral administration-is being developed for the prevention and treatment of thromboembolic disease. The pharmacokinetics, pharmacodynamics, and tolerability/safety of ximelagatran following a single 36-mg oral dose of ximelagatran +/- a single oral dose of alcohol (0.5 and 0.6 g ethanol/kg to women and men, respectively) were assessed in a randomized, open-label, two-way crossover study (n = 26). The 90% confidence intervals (CIs) and least squares mean estimates for the ratio of ximelagatran plus alcohol to ximelagatran alone for melagatran AUC (1.04 [90% CI = 1.00-1.08]) and C(max) (1.08 [90% CI = 1.03-1.14]) fell within the bounds demonstrating no interaction. Alcohol did not alter the melagatran-induced prolongation of the activated partial thromboplastin time or the good tolerability/safety profile of ximelagatran. In conclusion, the pharmacokinetics, pharmacodynamics, and tolerability/safety of oral ximelagatran were not affected by alcohol.

Differential effects of ethanol on spectral binding and inhibition of cytochrome P450 3A4 with eight protease inhibitors antiretroviral drugs

BACKGROUND

Cytochrome P450 3A4 (CYP3A4) is the most abundant CYP enzyme in the liver, which metabolizes approximately 50% of the marketed drugs including antiretroviral agents. CYP3A4 induction by ethanol and its impact on drug metabolism and toxicity is known. However, CYP3A4-ethanol physical interaction and its impact on drug binding, inhibition, or metabolism is not known, except that we have recently shown that ethanol facilitates the binding of a protease inhibitor (PI), nelfinavir, with CYP3A4. The current study was designed to examine the effect of ethanol on spectral binding and inhibition of CYP3A4 with all currently used PIs that differ in physicochemical properties.

METHODS

We performed type I and type II spectral binding with CYP3A4 at 0 and 20 mM ethanol and varying PIs' concentrations. We also performed CYP3A4 inhibition using 7-benzyloxy-4-trifluoromethylcoumarin substrate and NADPH at varying concentrations of PIs and ethanol.

RESULTS

Atazanavir, lopinavir, saquinavir, and tipranavir showed type I spectral binding, whereas indinavir and ritonavir showed type II. However, amprenavir and darunavir did not show spectral binding with CYP3A4. Ethanol at 20 mM decreased the maximum spectral change (δA(max)) with type I lopinavir and saquinavir, but it did not alter δA(max) with other PIs. Ethanol did not alter spectral binding affinity (K(D)) and inhibition constant (IC(50)) of type I PIs. However, ethanol significantly decreased the IC(50) of type II PIs, indinavir and ritonavir, and markedly increased the IC(50) of amprenavir and darunavir.

CONCLUSIONS

Overall, our results suggest that ethanol differentially alters the binding and inhibition of CYP3A4 with the PIs that have different physicochemical properties. This study has clinical relevance because alcohol has been shown to alter the response to antiretroviral drugs, including PIs, in HIV-1-infected individuals.

Effect of ethanol on spectral binding, inhibition, and activity of CYP3A4 with an antiretroviral drug nelfinavir

Cytochrome P450 3A4 (CYP3A4) is the most abundant CYP enzyme in the liver and metabolizes approximately 50% of the drugs, including antiretrovirals. Although CYP3A4 induction by ethanol and impact of CYP3A4 on drug metabolism and toxicity is known, CYP3A4-ethanol physical interaction and its impact on drug binding, inhibition, or metabolism is not known. Therefore, we studied the effect of ethanol on binding and inhibition of CYP3A4 with a representative protease inhibitor, nelfinavir, followed by the effect of alcohol on nelfinavir metabolism. Our initial results showed that methanol, ethanol, isopropanol, isobutanol, and isoamyl alcohol bind in the active site of CYP3A4 and exhibit type I spectra. Among these alcohol compounds, ethanol showed the lowest K(D) (5.9±0.34mM), suggesting its strong binding affinity with CYP3A4. Ethanol (20mM) decreased the K(D) of nelfinavir by >5-fold (0.041±0.007 vs. 0.227±0.038μM). Similarly, 20mM ethanol decreased the IC(50) of nelfinavir by >3-fold (2.6±0.5 vs. 8.3±3.1μM). These results suggest that ethanol facilitates binding of nelfinavir with CYP3A4. Furthermore, we performed nelfinavir metabolism using LCMS. Although ethanol did not alter k(cat), it decreased the K(m) of nelfinavir, suggesting a decrease in catalytic efficiency (k(cat)/K(m)). This is an important finding because alcoholism is prevalent in HIV-1-infected persons and alcohol is shown to decrease the response to antiretroviral therapy.

Role of ethanol in kava hepatotoxicity

Kava is known for its recreational, ceremonial and medicinal use in the Pacific. The aqueous non-alcoholic drink of kava rhizome produces intoxicating, relaxing and soothing effects. While kava's medicinal effects receive worldwide recognition, kava-containing products came under scrutiny after over 100 reports of spontaneous adverse hepatic effects. Many mechanisms have been postulated to explain the unexpected toxicity, one being pharmacokinetic interactions between kavalactones and co-administered drugs involving cytochrome P450 enzyme system. Alcohol is often co-injested in kava hepatotoxicity cases. This review evaluates the possible hepatotoxicity mechanisms involving alcohol and kava.

Rheumatoid arthritis, alcohol, leflunomide and methotrexate. Can changes to the BSR guidelines for leflunomide and methotrexate on alcohol consumption be justified?

INTRODUCTION

The summary of product characteristics for leflunomide and methotrexate recommend avoiding alcohol. By contrast, the latest British Society for Rheumatology (BSR) guidelines suggest that alcohol should be 'well within national limits'. A postal survey was performed of rheumatoid arthritis (RA) patients to address their alcohol consumption, and assess whether this influenced any rise in alanine transaminase (ALT) levels while on leflunomide or methotrexate.

METHODS

RA patients commenced on methotrexate or leflunomide within the preceding two years were identified using the departmental database. A total of 200 patients on methotrexate or leflunomide were sent questionnaires covering demographics, disease details, duration of disease-modifying anti-rheumatic drug (DMARD) use, previous medical and drug history, alcohol advice recalled, and alcohol consumption while on the drug. ALT levels at drug commencement and the highest level on the drug were recorded.

RESULTS

Replies were received from 69.5% of methotrexate and 57.5% of leflunomide patients. 68.6% of patients recalled receiving alcohol advice. 55.8% of leflunomide patients did not drink alcohol prior to taking the DMARD, compared with 39.4% of methotrexate patients. 27.7% of leflunomide patients continued to drink alcohol compared with 64.3% on methotrexate. For both drugs, no patterns emerged to suggest that baseline or highest ALT levels were influenced by higher levels of alcohol consumption.

DISCUSSION

No differences were found with either methotrexate or leflunomide for self-reported alcohol consumption influencing ALT levels. It is appropriate to give similar alcohol advice to patients beginning therapy with either methotrexate or leflunomide. This research has not found any evidence to contradict the relaxation of advice on alcohol consumption with methotrexate and leflunomide in the updated BSR guidelines.

Role of cytochrome P450 in drug interactions

Drug-drug interactions have become an important issue in health care. It is now realized that many drug-drug interactions can be explained by alterations in the metabolic enzymes that are present in the liver and other extra-hepatic tissues. Many of the major pharmacokinetic interactions between drugs are due to hepatic cytochrome P450 (P450 or CYP) enzymes being affected by previous administration of other drugs. After coadministration, some drugs act as potent enzyme inducers, whereas others are inhibitors. However, reports of enzyme inhibition are very much more common. Understanding these mechanisms of enzyme inhibition or induction is extremely important in order to give appropriate multiple-drug therapies. In future, it may help to identify individuals at greatest risk of drug interactions and adverse events.

Alcohol significantly lowers the seizure threshold in mice when co-administered with bupropion hydrochloride

BACKGROUND

Bupropion HCl is a widely used antidepressant that is known to cause seizures in a dose-dependent manner. Many patients taking antidepressants will consume alcohol, even when advised not to. Previous studies have not shown any interactions between bupropion HCl and alcohol. However, there have been no previous studies examining possible changes in seizure threshold induced by a combination of alcohol and bupropion HCl.

METHODS

Experimentally naïve female Swiss albino mice (10 per group) received either single doses of bupropion HCl (ranging from 100 mg/kg to 120 mg/kg) or vehicle (0.9% NaCl) by intraperitoneal (IP) injection in a dose volume of 10 ml/kg, and single-dose ethanol alone (2.5 g/kg), or vehicle, 5 min prior to bupropion dosing. The presence or absence of seizures, the number of seizures, the onset, duration and the intensity of seizures were all recorded for 5 h following the administration of ethanol.

RESULTS

The results show that administration of IP bupropion HCl alone induced seizures in mice in a dose-dependent manner, with the 120 mg/kg dose having the largest effect. The percentage of convulsing mice were 0%, 20%, 30% and 60% in the 0 (vehicle), 100, 110, and 120 mg/kg dose groups, respectively. Pretreatment with ethanol produced a larger bupropion HCl-induced convulsive effect at all the doses (70% each at 100, 110 and 120 mg/kg) and a 10% effect in the ethanol + vehicle only group. The convulsive dose of bupropion HCl required to induce seizures in 50% of mice (CD50), was 116.72 mg/kg for bupropion HCl alone (CI: 107.95, 126.20) and 89.40 mg/kg for ethanol/bupropion HCl (CI: 64.92, 123.10).

CONCLUSION

These results show that in mice alcohol lowers the seizure threshold for bupropion-induced seizures. Clinical implications are firstly that there may be an increased risk of seizures in patients consuming alcohol, and secondly that formulations that can release bupropion more readily in alcohol may present additional risks to patients.

Screening of 214 single nucleotide polymorphisms in 44 candidate cancer susceptibility genes: a case-control study on gastric and colorectal cancers in the Japanese population

OBJECTIVES

Single nucleotide polymorphisms (SNPs) have potential as markers for identifying genes responsible for common diseases and for personalized medicine. To investigate the association between polymorphisms and gastrointestinal (gastric and colorectal) cancer, we performed a hospital-based case-control study in Japan.

METHODS

We screened a total of 214 SNPs in 44 candidate genes by using a mass spectrometry-based technique (MassARRAY; Sequenom, Inc., San Diego, CA). In this study, 153 patients and 302 controls for gastric cancer and 121 patients and 245 controls for colorectal cancer were matched with regard to age, sex, and residential area. Genes were selected based on their possible interactions with the environment and lifestyle, and the candidate genes constitute those encoding xenobiotic metabolism enzymes, DNA repair enzymes, and other stress-related proteins. Each polymorphism was tested in controls to ensure its fit with Hardy-Weinberg equilibrium. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by conditional logistic regression analysis to estimate the association between genetic polymorphisms and the risk of gastric and colorectal cancers.

RESULTS

Twenty-one SNPs in nine genes were associated with the risk of gastric cancer (P < 0.05) and 15 SNPs in nine genes were associated with the risk of colorectal cancer (P < 0.05).

CONCLUSIONS

The findings of the present study will be the basis for future large-scale association studies of gene-environment factors using the candidate gene approach for the Japanese population.

CYP2E1 Rsa I polymorphism impacts on risk of colorectal cancer association with smoking and alcohol drinking

AIM: To investigate associations between the Rsa I polymorphism of CYP2E1 and risk of colorectal cancer.

METHODS: A case-control study was conducted with 315 colorectal cancer cases (105 colon, 210 rectal) and 439 population-based controls in Jiangsu Province of China. Genomic DNA samples were assayed for restriction fragment length polymorphisms in CYP2E1 by PCR amplification followed by digestion with Rsa I. Information on smoking and alcohol drinking was collected using a questionnaire. Odds ratios (ORs) were estimated with an unconditional logistic model.

RESULTS: The proportional distribution of the CYP2E1 Rsa I c1/c1, c1/c2 and c2/c2 genotypes were 61.4%, 35.6% and 3.0% in controls, 60.6%, 33.7% and 5.8% in colon cancer cases, and 58.4%, 34.0% and 7.7% in rectal cancer cases, respectively. A significant difference was noted between controls and rectal cancer cases (P = 0.029), the c2/c2 genotype being associated with elevated OR (adjusted age, sex and status of the smoking and alcohol drinking) for rectal cancer (1.64, 95% CI, 1.12-2.41, vs c1 allele carriers), but not for colon cancer. In interaction analysis between the CYP2E1 Rsa I genotype and smoking and drinking habits, we found a significant cooperative action between the c2/c2 genotype and alcohol drinking in the sex-, age-adjusted ORs for both colon (4.74, 95% CI, 1.10-20.40) and rectal (5.75, 95% CI, 1.65-20.05) cancers. Among non-smokers, the CYP2E1 Rsa I c2/c2 genotype was also associated with elevated ORs in the two sites (1.95, 95% CI, 0.99-3.86 and 2.30, 95% CI, 1.32-3.99).

CONCLUSION: The results of the present study suggest that the CYP2E1 c2/c2 genotype increases susceptibility to rectal cancer and the gene-environmental interactions between the CYP2E1 polymorphism and smoking or alcohol drinking exist for colorectal neoplasia in general.

Warfarin and its interactions with foods, herbs and other dietary supplements

Despite its complex pharmacokinetic and pharmacodynamic profile, warfarin is still one of the most widely used oral anticoagulant agents. Attaining optimal anticoagulation with this agent is clinically challenging in view of its many food and drug interactions. Inappropriate anticoagulation control can expose patients to an increased risk of bleeding or thromboembolic complications, due to over and underanticoagulation, respectively. Fluctuations in dietary vitamin K intake can have a significant effect on the degree of anticoagulation in patients treated with warfarin. In addition, the explosion in use of various dietary supplements and herbal products can lead to undesired outcomes on anticoagulant levels. The aim of this review is to discuss the scope and the potential clinical impact of the most commonly reported food, dietary supplement and herbal interactions with warfarin therapy. Practical steps for patients and providers to minimise these interactions are highlighted.

Cardiovascular drug therapy in the elderly

Pharmacokinetic considerations in the elderly include absorption, bioavailablility, drug distribution, half-life, drug metabolism, and drug excretion. There are numerous physiologic changes with aging that affect pharmacodynamics with alterations in end-organ responsiveness. This article discusses use of cardiovascular drugs in the elderly including digoxin, diuretics, beta-adrenergic blockers, angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, nitrates, calcium channel blockers, alpha-adrenergic blockers, antiarrhythmic drugs, lipid-lowering drugs, and anticoagulants. This article also discusses the adverse effects of cardiovascular drugs in the elderly, medications best to avoid in the elderly, and the prudent use of medications in the elderly.

Concentrations of scheduled prescription drugs in blood of impaired drivers: considerations for interpreting the results

We report the concentrations of scheduled prescription drugs in blood samples from people arrested in Sweden for driving under the influence of drugs (DUID). The investigation covered a 2 year period 2004 (N = 7052 cases) and 2005 (N = 7759 cases) and was prompted by recent legislation stipulating zero-concentration limits in blood for controlled substances. However, prescription drugs are exempt from the zero-limit law provided that the medication was being used in accordance with a doctor's prescription. The blood concentrations of various psychoactive substances were compared with the limits of quantitation of the analytic method used and the so-called therapeutic concentration range according to various reference books and tabulations. Diazepam [N = 1950 (26%)] and nordazepam [N = 2168 (28%)] were the therapeutic agents most frequently identified in these forensic blood samples along with other benzodiazepines such as alprazolam [N = 430 (5.6%)], flunitrazepam [N = 308 (4.0%)], and nitrazepam [N = 222 (2.9%)]. The newer hypnotics, exemplified by zolpidem [N = 148 (1.9%)] and zopiclone [N = 111 (1.5%)], were also high on the list of psychoactive substances identified. Interpreting the concentration of a prescription drug in blood in relation to whether the person had taken an overdose or was abusing the substance in question is not always easy. The age, gender, degree of obesity, and ethnicity of the person concerned; the pharmacokinetic profile of the drug; polymorphism of drug-metabolizing enzymes as well as liver and kidney function and blood hematocrit need to be considered. Among preanalytic factors, stability of the drug in blood after sampling, the type of tubes and preservatives used, the dosage form and route of administration deserve consideration. When therapeutic drug monitoring concentrations are compared with forensic toxicology results, then the plasma-to-whole blood distribution ratio of the drug also needs to be considered. In blood samples from DUID suspects, the concentrations of many commonly used sedatives and hypnotics exceeded the accepted therapeutic limits, which gives an indication of the abuse potential of these types of medications.

Fast gas chromatography-negative-ion chemical ionization mass spectrometry with microscale volume sample preparation for the determination of benzodiazepines and alpha-hydroxy metabolites, zaleplon and zopiclone in whole blood

Fast gas chromatography/negative-ion chemical ionization mass spectrometric (GC/NICI-MS) assay combined with rapid and nonlaborious sample preparation is presented for the simultaneous determination of benzodiazepines and alpha-hydroxy metabolites, zaleplon and zopiclone in whole blood. The compounds were extracted from 100 microl of whole blood by simultaneous multitube, microscale liquid-liquid extraction (LLE) and derivatized by N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), without the need for the time-consuming concentration stage. In the analytical separation, various parameters of fast GC/NICI-MS were applied, e.g. the use of hydrogen as a GC carrier gas, a high carrier gas velocity, a small film thickness of the analytical column, fast MS data acquisition, fast temperature ramping, and high initial and final temperatures of GC column. Sensitive identification, screening and quantitation of 18 compounds of interest were achieved in chromatographic separation in only 4.40 min. Accurate and reproducible results were obtained by using five different and carefully selected deuterated analogues on the basis of the chemical properties of the target analytes. Nevertheless, for alpha-OH-midazolam, and for bromazepam and flunitrazepam at low concentrations, the results can be considered only semiquantitative on the basis of the validation data. The extraction efficiencies ranged from 74.3 to 105.7% and the limits of quantitation (LOQ) from 1 to 100 ng ml(-1). Rapid sample preparation and fast chromatographic separation allowed cost-efficient, reliable and high sample-throughput analyses with a low amount of manual work. The method was fully validated and accredited according to EN ISO/IEC 17025 standards and is applicable for sensitive, reliable and quantitative determination of benzodiazepines, zaleplon and zopiclone, e.g. in clinical and forensic toxicology.

Declared and undeclared substance use among emergency department patients: a population-based study

AIMS

To estimate both self-reported and corrected prevalences of substance use in a population-based study of general hospital emergency department (ED) patients and predict undeclared use.

DESIGN

A state-wide cross-sectional, two-stage probability sample survey that incorporates toxicological screening.

SETTING

Seven Tennessee EDs in acute care, adult, civilian, non-psychiatric hospitals.

PARTICIPANTS

A total of 1502 Tennessee residents, 18 years of age and older, possessing intact cognition, able to give informed consent and not in police custody. Measurements Prevalence of self-reported current substance use by age, sex and type with correction for under-reporting based on toxicological screening. Covariates in the multivariate analysis of undeclared use were socio-demographics, ED visit circumstances, health-care coverage, prior health status and treatment history and tobacco addiction.

FINDINGS

Declared current use was highest for alcohol (females 26%, males 47%), marijuana (males 11%, females 6%) and benzodiazepines (females 10%, males 7%). After correction for under-reporting, overall use for any of the eight targeted substances rose from 44% to 56% for females and 61% to 69% for males. Largest absolute changes involved opioids, benzodiazepines, marijuana, amphetamines and/or methamphetamine, with little change for alcohol. Patients aged 65 years and older manifested excess undeclared use relative to patients aged 18-24 years, as did patients not reporting tobacco addiction or receiving substance abuse treatment.

CONCLUSION

Adjustment for under-reporting produced minimal change in the estimated prevalence of alcohol use. However, toxicological screening markedly increased estimates of other drug use, especially for the elderly, who may under-report medication use. Screening tests are useful tools for detecting undeclared substance use.

RESPONSES TO CARDIOVASCULAR DRUGS DURING ALCOHOL WITHDRAWAL

AIM

To present findings on the kinetics and dynamics of cardiovascular drugs during alcohol withdrawal (AW), compared with that observed in remission.

METHOD

Studies were reviewed and summarized.

RESULTS

A single-dose study in alcoholic patients with propranolol, a beta-adrenergic antagonist, showed that the negative inotropic effect was decreased and the bradycardiac effect increased during AW as compared with during early remission. The hypotensive effect of isosorbid dinitrate, commonly used as a vasodilatator, was weaker at the onset of AW, being associated with the decreased bioavailability of the drug. Verapamil, which is a L-type Ca2+ channel antagonist, produced a bradycardiac effect at the onset of AW, but no effect was observed in early remission. The effect was probably due to changes in L-type Ca2+ channels because no differences in verapamil concentrations between AW and early remission were observed.

CONCLUSION

Taken together, AW modifies the dynamics and kinetics of cardiac drugs, which may have an impact on the treatment of alcoholic patients with cardiac diseases.

Med-psych drug-drug interactions update. Antiretrovirals, part III: antiretrovirals and drugs of abuse

The third in a series reviewing the HIV/AIDS antiretroviral drugs, this report summarizes the interactions between antiretrovirals and common drugs of abuse. In an overview format for primary care physicians and psychiatrists, the metabolism and drug interactions in the context of antiretroviral therapy are presented for the following drugs of abuse: alcohol, benzodiazepines, cocaine, GHB (liquid X), ketamine (special K), LSD (acid), MDMA (Ecstasy), opiates, PCP (angel dust), and THC (marijuana).

Medication use in the elderly patient: focus on the perioperative/perianesthesia setting

As the population ages, the use of multiple medications also increases. Polypharmacy (taking multiple drugs at a time) presents concerns to the perianesthesia nurse who is caring for the geriatric patient. The pharmacokinetics and pharmacodynamics of drugs are often altered in older adult patients. Adverse drug reactions and drug interactions occur more often in geriatric patients than in younger patients. For these reasons, the benefits and risks of multiple medications and the administration of certain types of drugs must be carefully considered in the elderly patient. The selection of any medication should be individually based on the benefits and risks. Adverse drug reactions play a significant role in hospitalization for the general population, and the elderly are more susceptible to these. These drug reactions often contribute to significant morbidity as well as mortality. Medications need to be considered carefully in the older adult patient, but perhaps more so in the perioperative/perianesthesia period. Drug interactions are diverse. The type of anesthesia may influence the patient's outcome, depending on the medications the patient is currently taking. The patient's response to the stress of surgery is also affected by individual medical conditions as well as medications the patient is currently receiving Polypharmacy, inappropriate medications, adverse drug reactions, drug-disease issues, and drug interactions in the geriatric population are concerns in the perioperative/perianesthesia setting.

Ethanol's effects on gait dynamics in mice investigated by ventral plane videography

BACKGROUND

Performance of mice in motor function tests for ethanol sensitivity is often task dependent, not reflective of coordinated movement, and reported qualitatively. Therefore, we applied a new imaging technique to record and quantify coordinated gait dynamics in mice in response to ethanol.

METHODS

We applied ventral plane videography to record and report gait indices in mice walking on a transparent treadmill belt. We examined the effects of ethanol on gait in C57BL/6J (B6) and DBA/2J (D2) mice walking at a speed of 25 cm/sec. B6 and D2 are two inbred strains that are widely used to study the genetic influences of ethanol on motor function.

RESULTS

Gait posture in D2 mice was less stable than in B6 mice. B6 mice always showed an alternate step sequence, whereas D2 mice sometimes showed cruciate and rotary step sequences. Ethanol in increasing doses increased stride frequency, decreased stride length, and increased stride length variability in D2 mice but not in B6 mice. The forelimb braking duration was significantly shortened and the hind limb propulsion duration was significantly prolonged with a high dose of ethanol in D2 mice but not in B6 mice. Differences in gait indices between the two strains of mice were more pronounced of the forelimbs with the highest dose of ethanol (2.75 g/kg).

CONCLUSION

Our data suggest that the higher susceptibility of D2 compared with B6 mice to the effects of ethanol on motor function may be attributed to less stable basal gait characteristics that are perturbed by ethanol. The ability of this method to quantify step sequence patterns and gait indices of forelimb and hind limbs could provide new data regarding ethanol-induced motor incoordination.

Genetic polymorphisms of CYP2E1, GSTT1, GSTP1, GSTM1, ALDH2, and ODC and the risk of advanced precancerous gastric lesions in a Chinese population

There have been few studies of the associations of genetic polymorphisms with precancerous gastric lesions. We conducted a cross-sectional study to compare the prevalences of several genetic polymorphisms in 302 subjects with mild chronic atrophic gastritis with prevalences in 606 subjects with deep intestinal metaplasia or dysplasia. This stratified random sample of 908 subjects was selected and analyzed for genetic polymorphisms from 2,628 individuals who had gastric biopsies with histopathology in 1989 in Linqu County, Shandong Province, China. In subjects with mild chronic atrophic gastritis, the frequencies of the variant (less common) alleles of CYP2E1 RsaI, CYP2E1 DraI, GSTP1, ALDH2, and ODC were, respectively, 0.156, 0.201, 0.189, 0.190, and 0.428. The frequencies of the null genotypes of GSTM1 and GSTT1 in the mild chronic atrophic gastritis group were 0.509 and 0.565, respectively. Comparing mild chronic atrophic gastritis with deep intestinal metaplasia or any degree of dysplasia, we found no statistically significant associations with any genotype from these loci for dominant, additive, or recessive inheritance models. There was no statistically significant evidence of multiplicative interactions between any pair of genotypes based on CYP2E1 RsaI, CYP2E1 DraI, GSTP1, GSTM1, or GSTT1; nor between Helicobacter pylori status and any of these five loci; nor between smoking status and GSTP1, GSTM1, or GSTT1; nor between alcohol consumption and ALDH2. Statistically significant interactions were noted between salt consumption and GSTP1 and between sour pancake consumption and CYP2E1 RsaI. There was, moreover, a statistically significant interaction (odds ratio, 1.78; 95% confidence interval, 1.03-3.08) between CYP2E1 DraI and smoking at least one cigarette per day. A positive but not statistically significant interaction was also seen between CYP2E1 RsaI and smoking status. These polymorphisms do not seem to govern progression from mild chronic atrophic gastritis to advanced precancerous gastric lesions, but the effects of smoking may be accentuated in individuals carrying variants of CYP2E1.

Assessing substance abuse treatment need: a statewide hospital emergency department study

STUDY OBJECTIVE

Health care providers in hospital emergency departments rarely take substance abuse histories or assess associated treatment need. This study compares documentation of psychoactive drug-related diagnoses for adult ED patients in medical records with treatment need assessed through self-report, toxicologic screening, and Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), criteria.

METHODS

A statewide, 2-stage, probability sample survey was conducted in 7 Tennessee general hospital EDs from June 1996 to January 1997. Main outcome measures were the prevalence of diagnosed substance abuse problems, positive bioassay results, denied use, and treatment need. Sensitivity and multivariate analyses were conducted by using varied case definitions of treatment need.

RESULTS

Thirty-one percent (95% confidence interval [CI] 27.3% to 34.7%) of screened ED patients (n=1,330) had positive test results for substance use. Their prevalence of denial of use in the 30 days before the survey ranged from 10% for alcohol (95% CI 5.7% to 14.3%) to 100% for phencyclidine. One percent of all ED patients (n=1,502) had a recorded diagnosis of substance abuse. By contrast, as many as 27% (95% CI 23.3% to 31.8%) were assessed as needing substance abuse treatment on the basis of a comprehensive case definition that accounted for denial and positive test results. A sensitivity analysis using other case definitions is also presented. For example, 4% (95% CI 2.8% to 5.3%) of patients met the very strict definition of DSM-IV current drug dependence only. Under the comprehensive case definition, TennCare patients (adjusted odds ratio [OR] 1.63; 95% CI 1.30 to 2.05) and Medicare patients (adjusted OR 2.50; 95% CI 1.34 to 4.65) showed excess treatment need relative to the privately insured. Excess need was also exhibited by patients reporting 1 or more prior ED visits in the past year (adjusted OR 1.62; 95% CI 1.13 to 2.31) and by patients taking 2 or more hours to reach the ED after the onset of injury or illness (adjusted OR 1.54; 95% CI 1.16 to 2.04). Treatment need was inversely associated with age. Irrespective of case definition, less than 10% of ED patients who needed substance abuse treatment were receiving such treatment.

CONCLUSION

EDs can be important venues for detecting persons in need of substance abuse treatment.

Interaction of alcohol and drugs in fatal poisonings

In Finnish data from 1995-2000, 1006 fatal poisonings due to alcohol (ethanol), a single drug or both were statistically analysed in retrospect to evaluate the interaction between alcohol and drugs. In 53% of these cases, low concentrations of some common benzodiazepines were present. The median postmortem blood alcohol concentration (BAC) was 3.3 percent per thousand (w/w) in the 615 alcohol poisonings, but significantly lower, ranging from 1.3 to 1.7 percent per thousand, when promazine, doxepin, amitriptyline or propoxyphene were found together with alcohol. When levomepromazine, temazepam or zopiclone were present, the median BAC was also significantly lower, 2.5-2.7 percent per thousand. Citalopram and diltiazem did not exhibit a significant effect. The median BAC was significantly lower in cases with high concentrations than in those with low concentrations of a drug (excluding citalopram), suggesting a positive concentration-effect relationship. Fatal toxicity indices (FTIs) were calculated by relating the number of deaths caused by a drug to the corresponding sales figures. Promazine had an extremely high FTI, followed by levomepromazine, propoxyphene, doxepin and amitriptyline. The other drugs had relatively low FTIs. The results reflect not only the acute toxicity of a given drug-alcohol combination but also the manners of use and abuse of these drugs.

Role of variability in explaining ethanol pharmacokinetics: research and forensic applications

Variability in the rate and extent of absorption, distribution and elimination of ethanol has important ramifications in clinical and legal medicine. The speed of absorption of ethanol from the gut depends on time of day, drinking pattern, dosage form, concentration of ethanol in the beverage, and particularly the fed or fasting state of the individual. During the absorption phase, a concentration gradient exists between the stomach, portal vein and the peripheral venous circulation. First-pass metabolism and bioavailability are difficult to assess because of dose-, time- and flow-dependent kinetics. Ethanol is transported by the bloodstream to all parts of the body. The rate of equilibration is governed by the ratio of blood flow to tissue mass. Arterial and venous concentrations differ as a function of time after drinking. Ethanol has low solubility in lipids and does not bind to plasma proteins, so volume of distribution is closely related to the amount of water in the body, contributing to sex- and age-related differences in disposition. The bulk of ethanol ingested (95-98%) is metabolised and the remainder is excreted in breath, urine and sweat. The rate-limiting step in oxidation is conversion of ethanol into acetaldehyde by cytosolic alcohol dehydrogenase (ADH), which has a low Michaelis-Menten constant (Km) of 0.05-0.1 g/L. Moreover, this enzyme displays polymorphism, which accounts for racial and ethnic variations in pharmacokinetics. When a moderate dose is ingested, zero-order elimination operates for a large part of the blood-concentration time course, since ADH quickly becomes saturated. Another ethanol-metabolising enzyme, cytochrome P450 2E1, has a higher Km (0.5-0.8 g/L) and is also inducible, so that the clearance of ethanol is increased in heavy drinkers. Study design influences variability in blood ethanol pharmacokinetics. Oral or intravenous administration, or fed or fasted state, might require different pharmacokinetic models. Recent work supports the need for multicompartment models to describe the disposition of ethanol instead of the traditional one-compartment model with zero-order elimination. Moreover, appropriate statistical analysis is needed to isolate between- and within-subject components of variation. Samples at low blood ethanol concentrations improve the estimation of parameters and reduce variability. Variability in ethanol pharmacokinetics stems from a combination of both genetic and environmental factors, and also from the nonlinear nature of ethanol disposition, experimental design, subject selection strategy and dose dependency. More work is needed to document variability in ethanol pharmacokinetics in real-world situations.