What the lab can and cannot do: clinical interpretation of drug testing results.

Urine drug testing is one of the objective tools available to assess adherence. To monitor adherence, quantitative urinary results can assist in differentiating "new" drug use from "previous" (historical) drug use. "Spikes" in urinary concentration can assist in identifying patterns of drug use. Coupled chromatographic-mass spectrometric methods are capable of identifying very small amounts of analyte and can make clinical interpretation rather challenging, specifically for drugs that have a longer half-life. Polypharmacy is common in treatment and rehabilitation programs because of co-morbidities. Medications prescribed for comorbidities can cause drug-drug interaction and phenoconversion of genotypic extensive metabolizers into phenotypic poor metabolizers of the treatment drug. This can have significant impact on both pharmacokinetic (PK) and pharmacodynamic properties of the treatment drug. Therapeutic drug monitoring (TDM) coupled with PKs can assist in interpreting the effects of phenoconversion. TDM-PKs reflects the cumulative effects of pathophysiological changes in the patient as well as drug-drug interactions and should be considered for treatment medications/drugs used to manage pain and treat substance abuse. Since only a few enzyme immunoassays for TDM are available, this is a unique opportunity for clinical laboratory scientists to develop TDM-PK protocols that can have a significant impact on patient care and personalized medicine. Interpretation of drug screening results should be done with caution while considering pharmacological properties and the presence or absence of the parent drug and its metabolites. The objective of this manuscript is to review and address the variables that influence interpretation of different drugs analyzed from a rehabilitation and treatment programs perspective.

FASD: folic acid and formic acid - an unholy alliance in the alcohol abusing mother.

Alcohol consumption during pregnancy remains a significant cause of preventable birth defects and developmental disabilities; however, the mechanism of toxicity remains unclear. Methanol is present as a congener in many alcoholic beverages and is formed endogenously. Because ethanol is preferentially metabolized over methanol, it has been found in the sera and cerebro-spinal fluid of alcoholics. Toxicity resulting from methanol has been attributed to formic acid. Formic acid is present in significantly higher quantities in the biofluids of alcoholics. These higher levels can be cytotoxic and cause neuronal cell death. However, the adverse effects can be mitigated by adequate levels of hepatic folic acid, because formic acid elimination depends on folic acid. During pregnancy, folate concentrations are at least 2-fold higher in cord blood then in maternal blood, owing to increased folate requirements. The reverse has been demonstrated in pregnancies with alcohol abuse, suggesting downregulation of folate transporters and low fetal folate levels. Moreover, formic acid can cross the placenta and its adverse effects can be mitigated by folic acid. Thus, the combination of low fetal folate levels and presence of formic acid form a potent cytotoxic combination that may play a significant role in the etiology of fetal alcohol spectrum disorder.

Differential expression of astrocytic connexins in a mouse model of prenatal alcohol exposure.

Maternal alcohol consumption during gestation can cause serious injury to the fetus, and may result in a range of physiological and behavioral impairments, including increased seizure susceptibility, that are collectively termed fetal alcohol spectrum disorder (FASD). The cellular mechanisms underlying increased seizure susceptibility in FASD are not well understood, but could involve altered excitatory coupling of neuronal populations mediated by gap junction proteins. We utilized a mouse model of the prenatal alcohol exposure (PAE) to study the expression pattern of connexin (Cx) major components of gap junctions, and pannexin proteins, which form membrane channels, in the brain of 2-3weeks old PAE and control postnatal offspring. PAE during the first trimester-equivalent period of pregnancy in mice resulted in significant up-regulation of Cx30 mRNA and Cx30 total protein in the hippocampus of PAE animals compared to age-matched controls. Surface level expression of both dimeric and monomeric Cx30 were also found to be significantly up-regulated in both hippocampus and cerebral cortex of PAE animals compared to age-matched controls. On the membrane surface, the fast migrating form of Cx43 was found to be up-regulated in the hippocampus of PAE mice. However, we did not see any up-regulation of the phosphorylated forms of Cx43 on the membrane surface. These results indicate that the expression and processing of astrocytic connexins (Cx30, Cx43) are up-regulated in the brain of PAE offspring, and these changes could play a role in the cerebral hyperexcitability observed in these animals.

Evaluating external contamination of polybrominated diphenyl ethers in human hair: clinical and research implications.

BACKGROUND: Human hair is a well-validated matrix for detecting a variety of xenobiotics, including drugs of abuse (cocaine, tetrahydrocannabinol, and morphine) and fatty acid ethyl ethers. Recent studies have shown that hair can also be useful in determining an individual's exposure to polybrominated diphenyl ethers (PBDEs), flame retardants that contaminate the dust in our daily environment. Hair processing before assay varies with each analyte; in particular, the wash protocol must be optimized to remove external contaminants while not affecting levels of the chemical of interest. The aim of this study was to determine whether hair needs to be washed before analysis for PBDEs, and if so, which protocol is most effective to ensure that the level of PBDEs is neither overestimated nor underestimated. METHOD: Individual hair samples from 10 adults (5 men and 5 women) were subjected to 4 different wash protocols: (1) no wash, (2) water, (3) 10% sodium dodecyl sulfate (SDS), and (4) hexane. Both the washes and hair were analyzed for 8 PBDEs by gas chromatography/mass spectrometry. RESULTS: The sum of PBDEs (ΣPBDEs) in the washes was (1) no wash: 0 pg/mg, (2) water: 0.39 ± 0.19 (mean ± SEM), (3) 10% SDS: 1.34 ± 0.68, and (4) hexane: 1.92 ± 0.87. The ΣPBDEs in the hair were: (1) no wash: 20.32 ± 3.05, (2) water: 20.30 ± 2.41, (3) 10% SDS: 19.27 ± 1.87, and (4) hexane: 16.91 ± 2.89. Washing with water, 10% SDS, and hexane decreased the PBDE levels by 1.9%, 7%, and 11.4%, respectively (P < 0.05). CONCLUSIONS: Thus, of the washes evaluated, water is the wash that had the least effect on total PBDE concentrations, providing the best evaluation of an individual's exposure to PBDEs.

The Effectiveness of Folate-Fortified Oral Contraceptives in Maintaining Optimal Folate Levels to Protect Against Neural Tube Defects: A Systematic Review.

OBJECTIVE: To conduct a systematic review evaluating the effectiveness of a folate-fortified oral contraceptive preparation in increasing blood folate concentrations to levels providing optimal protection against neural tube defects (> 906 nmol/L). METHODS: We searched Medline, EMBASE, Web of Science, and the Cochrane Library for human studies published from inception to June 2013 that evaluated oral contraceptive use and folate status. Case-control studies, cohort studies, and clinical trials were included. Efficacy and bioequivalence data were evaluated from included studies. RESULTS: Overall, efficacy and bioequivalence data for the folate-fortified oral contraceptive show that it is at least as effective as folic acid alone in raising blood folate concentrations, and that the concomitant administration of folate with the oral contraceptive component does not affect its absorption or kinetics. CONCLUSION: A folate-fortified oral contraceptive preparation provides an option for women to maintain blood folate levels, especially those who may be planning a family after the cessation of oral contraceptive therapy.

Objectif : Mener une analyse systématique de l'efficacité d'un contraceptif oral enrichi en folate pour ce qui est d'accroître les concentrations sanguines en folate jusqu'aux niveaux offrant une protection optimale contre les anomalies du tube neural (> 906 nmol/l). Méthodes : Nous avons mené des recherches dans Medline, EMBASE, Web of Science, et la Cochrane library en vue d'en tirer les études menées chez l'homme, publiées entre le début de nos travaux et juin 2013, qui ont évalué l'utilisation de contraceptifs oraux et les taux de folate. Les études cas-témoins, les études de cohorte et les essais cliniques ont été admis aux fins de notre analyse. Les issues ont été soumises à une méta-analyse faisant appel à un modèle à effets aléatoires. Résultats : De façon globale, les données sur l'efficacité et la bioéquivalence en ce qui concerne les contraceptifs oraux enrichis en folate indiquent que ceux-ci sont au moins aussi efficaces que l'acide folique administré seul pour ce qui est d'augmenter les concentrations sanguines en folate; elles indiquent également que l'administration concomitante de folate et d'un composé contraceptif oral n'en affecte ni l'absorption ni la cinétique. Conclusion : Les contraceptifs oraux enrichis en folate offrent une option aux femmes pour le maintien de leurs taux sanguins de folate; cette option s'avère particulièrement adaptée aux femmes qui pourraient souhaiter devenir enceintes à la suite de l'abandon de la contraception orale.

Association Between Use of Oral Contraceptives and Folate Status: A Systematic Review and Meta-Analysis.

OBJECTIVE: To conduct a systematic review and meta-analysis of the effect of oral contraceptive use on plasma and red blood cell (RBC) folate concentrations. METHODS: We searched Medline, EMBASE, Web of Science, and the Cochrane library for human studies published from inception to June 2013 evaluating oral contraceptive use and folate status. Case-control studies, cohort studies, and clinical trials were included. A random-effects model of outcomes was used for the meta-analysis. RESULTS: A total of 2831 women in 17 studies were included in the analysis. In those whose plasma folate concentrations were available, there was a significant folate-lowering effect of oral contraceptives observed (mean reduction 1.27 µg/L; 95% CI 1.85 to 0.69, P < 0.001). Similarly, after analyzing data from 1389 women in 12 studies whose RBC folate concentrations were available, significantly lower folate status was observed among oral contraceptive users (mean reduction 59.32 µg/L; 95% CI 58.03 to 23.04, P < 0.001). CONCLUSION: Because of the reduction in blood folate concentrations associated with the use of oral contraceptives, it is critical for women of childbearing age to continue folate supplementation during oral contraceptive use.

Objectif : Mener une analyse systématique et une méta-analyse quant à l'effet du recours à la contraception orale sur les concentrations plasmatiques et érythrocytaires en folate. Méthodes : Nous avons mené des recherches dans Medline, EMBASE, Web of Science et la Cochrane library en vue d'en tirer les études menées chez l'homme, publiées entre le début de nos travaux et juin 2013, qui ont évalué l'utilisation de contraceptifs oraux et les taux de folate. Les études cas-témoins, les études de cohorte et les essais cliniques ont été admis aux fins de notre analyse. Un modèle à effets aléatoires quant aux issues a été utilisé dans le cadre de la méta-analyse. Résultats : Au total, 2 831 femmes issues de 17 études ont été admises à l'analyse. Chez les femmes pour lesquelles les concentrations plasmatiques en folate étaient disponibles, nous avons constaté que les contraceptifs oraux exerçaient un effet considérable d'atténuation de ces concentrations (baisse moyenne, 1,27 µg/l; IC à 95 %, 1,85 - 0,69, P < 0,001). De façon semblable, après avoir analysé les données traitant de 1 389 femmes issues de 12 études pour lesquelles les concentrations érythrocytaires en folate étaient disponibles, nous avons constaté une baisse considérable de ces concentrations chez les utilisatrices de contraceptifs oraux (baisse moyenne, 59,32 µg/l; IC à 95 %, 58,03 - 23,04, P < 0,001). Conclusion : En raison de la baisse des concentrations sanguines en folate qui sont associées à l'utilisation de contraceptifs oraux, il est crucial que les femmes en âge de procréer qui ont recours à une telle contraception continuent à prendre une supplémentation en folate.

False-positive meconium test results for fatty acid ethyl esters secondary to delayed sample collection.

BACKGROUND: Meconium analysis for fatty acid ethyl esters (FAEEs) is a validated method for identifying heavy prenatal ethanol (EtOH) exposure. This study investigated whether delayed sample collection can result in false-positive test results for FAEEs because of collection of samples potentially contaminated with postnatally produced stool. METHODS: Serial excretions were prospectively collected from neonates born to nondrinking mothers to capture the transition from meconium to postnatal stool. These were analyzed for FAEEs using headspace-solid phase microextraction and gas chromatography-mass spectrometry. Experiments involving incubation of samples with glucose or EtOH were performed to explore a potential mechanism of FAEE elevation. RESULTS: A total of 136 samples were collected from 30 neonates during their first few days of life (median of 4 samples/baby over a mean period of 68.5 hours postpartum). Although the first-collected meconium sample tested negative for FAEEs in all babies, later samples tested above the 2 nmol/g positive cutoff in 19 of 30 babies. Median time to appearance of FAEE-positive samples was 59.2 hours postpartum. In vitro experiments demonstrated that FAEE levels can be further increased in late samples (likely containing postnatal stool) after incubation with glucose, and that FAEEs are readily formed in meconium in the presence of EtOH. CONCLUSIONS: Collection of samples excreted later in the postpartum period can lead to false-positive test results for FAEEs, which could be because of contamination with dietary components of postnatally produced stool and EtOH-producing microorganisms. Clinically, it is critical to collect the earliest possible excretion for determination of FAEEs to ensure that the FAEE content is representative of in utero EtOH exposure.

Dosage requirements for periconceptional folic acid supplementation: accounting for BMI and lean body weight.

OBJECTIVE: To determine folic acid dosage requirements for individuals across a broad range of BMI values, using dose per kilogram lean body weight (LBW) as a primary predictor of systemic exposure. Steady-state folate concentrations of ≥ 15.9 nmol/L were assumed to be sufficient for reducing the risk for neural tube defects in the general population. METHODS: Data from a recent study of single-dose folic acid pharmacokinetics among 12 obese and 12 non-obese women of childbearing age were analyzed to determine expected steady-state concentrations. The mean folic acid dose per kilogram LBW that achieved serum folate concentrations of ≥ 15.9 nmol/L was applied to a broad range of BMI values to evaluate daily dose requirements. RESULTS: Modest differences in folic acid requirements were noted for individuals among the non-obese, overweight, and obese categories. The current supplementation guidelines suggesting a daily dose of 0.4 mg appear to satisfy the needs of women at even the upper extremes of obesity. However, because even with appropriate folate supplementation obese women have an increased risk of neural tube defects, and they may benefit from higher intake and higher serum concentrations of folic acid. CONCLUSION: Current guidelines recommend an adequate folic acid dose for obese women of childbearing age. Thus, it is unlikely that folate deficiency is associated with the elevated risk for neural tube defects in this population.

Methadone: a review of drug-drug and pathophysiological interactions.

Numerous established and potential drug interactions with methadone are clinically important in people treated with methadone either for addiction or for chronic pain. Methadone users often have comorbidities and are prescribed drugs that may interact with methadone. Methadone is extensively metabolized by cytochrome P450 (CYP) 3A4 and to a lesser extent by CYP 1A2, 2D6, 2D8, 2C9/2C8, 2C19, and 2B6. Eighty-six percent of methadone is protein bound, predominately to α1-acid glycoprotein (AGP). Polymorphisms in or interactions with CYPs that metabolize methadone, changes in protein binding, and other pathophysiological conditions affect the pharmacokinetic properties of methadone. It is critical for health care providers who treat patients on methadone to have adequate information on the interactions of methadone with other drugs of abuse and other medications. We set out to describe drug-drug interactions as well as physiological and pathophysiological factors that may impact the pharmacokinetics of methadone. Using MEDLINE, we conducted a systematic search for papers and related abstracts published between 1966 and June 2010. Keywords that included methadone, drug-drug interactions, CYP P450 and AGP identified a total of 7709 papers. Other databases, including the Cochrane Database of Systematic Reviews and Scopus, were also searched; an additional 929 papers were found. Final selection of 286 publications was based on the relevance of each paper to the topic. Over 50 such interactions were found. Interactions of methadone with other drugs can lead to increased or decreased methadone drug levels in patients and result in potential overdose or withdrawal, respectively. The former can contribute to methadone's fatality. Prescribers of methadone and pharmacists should enquire about any new medications (including natural products and over-the-counter medications) periodically, and especially when an otherwise stable patient suddenly experiences drug craving, withdrawal or intoxication.

A comparison of folic acid pharmacokinetics in obese and nonobese women of childbearing age.

BACKGROUND: Although maternal folate deficiency during the periconceptional period represents a major risk factor for neural tube defects, obesity has been recognized as an additional risk factor. Studies have identified an increased risk for neural tube defect-affected births among obese mothers even after adjusting for folic acid supplementation. However, although folic acid intake may have been at the recommended dose in these samples, blood folate concentrations were not monitored to ensure that protective levels were reached. Hence, there is a need to compare folic acid pharmacokinetics in obese and nonobese women of childbearing age. METHODS: Healthy obese (n=12) and nonobese (n=12) women of childbearing age volunteered to participate. Each obese participant was matched to a nonobese participant and assigned an equivalent dose of folic acid per kilogram body weight. Folic acid was orally administered after a 6-hour fast, and blood samples were taken over a 10-hour period to evaluate pharmacokinetic parameters. RESULTS: Area under the time-concentration curve (AUC) was found to be significantly higher in the obese group (P=0.008). Defining AUC as a function of dose per kilogram lean body weight (LBW) was found to be a stronger predictor than dose per kilogram total body weight (r=0.90 and 0.76, respectively). CONCLUSIONS: This indicates that the body tightly controls systemic exposure to folic acid, with 90% of the variability in AUC controlled by the dose per kilogram LBW. Periconceptional supplementation recommendations may need to be adjusted to account for LBW differences in the obese population.

Prevalence of Fetal Alcohol Exposure by Analysis of Meconium Fatty Acid Ethyl Esters; A National Canadian Study.

Our study aimed to estimate the prevalence of heavy fetal alcohol exposure through the analysis of meconium FAEEs as an objective biomarker of fetal exposure. We conducted a study on meconium samples collected nationwide through the Maternal-Infant Research on Environmental Chemicals (MIREC) Study Group. FAEE in meconium was quantified by an established headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME GC-MS). Out of 1315 samples collected in 10 Canadian obstetric units coast to coast between 2008-2011, the estimated prevalence of positive meconium FAEE ranged between 1.16% and 2.40%, translating into at least 1800 new cases of FASD in Canada each year. Positive maternal self- reports of heavy alcohol use were tenfold lower (0.24%). Use of meconium FAEE revealed tenfold more cases of heavy exposure to maternal drinking than did maternal reports. The use of objective measures of maternal alcohol exposure is critical in accurately estimating risks and in monitoring effective prevention of FASD.

A simple and rapid HPLC method for the detection of glyburide in plasma original research communication (analytical).

INTRODUCTION: Although a variety of HPLC methods have been previously described for the quantification of glyburide, attempts to implement them clinically have been unsuccessful. Some are time consuming, expensive, or not directly applicable to human plasma. Others are outdated, as the necessary materials are no longer available. OBJECTIVE: To describe a simple, rapid, and sensitive HPLC method for the analysis of human plasma and perfusate. DESIGN AND METHOD: Samples were extracted by liquid-liquid extraction with chloroform at neutral pH. Glyburide was detected at 254 nm, with a total run time of 7 min per sample. RESULTS: Standard curves of 50 to 400 ng/mL of glyburide were linear (r(2)=0.998). Inter-day and intra-day sample coefficient of variations were 8% and 4%, respectively. Recoveries ranged from 71 to 75% in human plasma samples for the 20-400 ng/mL concentration range. CONCLUSION: Clinically, this method can be applied in the therapeutic drug monitoring of glyburide.

Folate fortification and supplementation--are we there yet?

BACKGROUND: Folic acid fortification of flour has significantly decreased the incidence of neural tube defects (NTDs). We aimed at examining whether Ontario women of child-bearing age exhibit protective levels of RBC folate. METHODS: We reviewed laboratory databases on RBC folic acid from pre and post fortification years. The data included age, gender, RBC folate, hemoglobin, mean cell volume and pregnancy test. We examined a sub-set of females at ages 14-45 years who were non-anemic and normocytic. Complete protection against NTD was defined as RBC folate concentration above 900 nmol/L. RESULTS: In 2006, 40% of the women of child-bearing age and 36% of pregnant women, exhibited RBC folate levels below 900 nmol/L, rendering them sub-optimally protected against NTD. CONCLUSION: A considerable proportion of pregnant women is still at risk of having a baby with NTD. This should be remedied by increasing the mandatory concentrations of folic acid required in flour, complemented by public education and increasing the folic acid in prenatal supplements.

The effect of amitriptyline, gabapentin, and carbamazepine on morphine-induced hypercarbia in rabbits.

BACKGROUND: Severe exacerbation of chronic neuropathic pain often requires morphine in patients already treated with drugs such as tricyclic antidepressants, carbamazepine and gabapentin. However, it is unclear if a combination of these drugs intensifies the effects of morphine on the respiratory system and, if so, whether these effects are due to pharmacokinetic or pharmacodynamic interaction. METHODS: We gave rabbits (n=6 per group) the following drugs daily for 4 days: subcutaneous normal saline 1 mL (control); amitriptyline subcutaneously 7 mg/kg; carbamazepine orally 100 mg/kg; gabapentin subcutaneously 25 mg/kg; and all three drugs concurrently (combination). On the fifth day, morphine 5 mg/kg was given IV, and Paco2, Pao2 and pH were measured. Morphine, morphine 3-glucoronide and morphine 6-glucoronide concentrations were measured in the plasma over the 4 h period after morphine injection. RESULTS: Compared with controls, premorphine baseline Paco2 was significantly higher (P<0.05) in the amitriptyline group. Postmorphine Paco2 was significantly higher in the amitriptyline and combination groups at all time points over the 240 min, and in the gabapentin group at 10 and 30 min after morphine injection (P<0.05). Peak Paco2 was significantly higher in the amitriptyline group (58.4+/-1.6 mm Hg; mean SD, P<0.005) and in the combination group (57.4+/-1.0 mm Hg, P<0.02) than in the control group (50.2+/-5.2 mm Hg). Similarly, the area under the curve of Paco2 from zero to 240 min was significantly higher in the amitriptyline and combination groups than in the control (P<0.001). There were no significant differences among the groups in plasma concentrations of morphine and its metabolites. CONCLUSIONS: We conclude that pretreatment with amitriptyline increases morphine- induced hypercarbia through pharmacodynamic processes. The effects of carbamazepine or gabapentin were not obvious in this model.

Association of In Utero Exposure to Polybrominated Diphenyl Ethers With the Risk of Hypospadias.

Importance: Polybrominated diphenyl ethers (PBDEs) are added to many consumer products as flame retardants, and their endocrine-disrupting properties are a growing health concern in pregnancy. Objective: To investigate whether in utero PBDE exposure as measured in maternal hair is associated with increased risk for hypospadias. Design, Setting, and Participants: In this case-control study, the setting was the urology clinic of a tertiary pediatric hospital between January 3, 2011, and April 1, 2013. Participants were children diagnosed as having hypospadias and their mothers and a control group of children without hypospadias and their mothers. Dates of data analysis were September 3, 2017, to December 28, 2017. Exposures: Gestational exposure to 8 PBDEs as measured in the 3-cm segment closest to the skull of maternal hair by gas chromatography-mass spectroscopy as a proxy for in utero exposure. The mothers resided in the same household for the duration of their pregnancy. Main Outcomes and Measures: Difference in total maternal hair PBDE levels between the hypospadias and control groups. Results: Total PBDE levels were significantly higher among mothers of infants with hypospadias (n = 152) (total PBDE level, 51.4 pg/mg; interquartile range, 35.8-78.5 pg/mg) than among controls (n = 64) (total PBDE level, 35.8 pg/mg; interquartile range, 18.1-69.9 pg/mg) (P = .02). Of the 152 women with sufficient hair samples for analysis in the case group, 89 completed a questionnaire and were included in a multivariable analysis, and of the 64 women with sufficient hair samples for analysis in the control group, 54 completed a questionnaire and were included in a multivariable analysis. Adjusting for potential confounders, hypospadias was associated with a relative 48.2% (95% CI, 23.2%-65.4%) higher maternal level of total PBDE levels in the multivariable analysis. Conclusions and Relevance: In this analysis, mothers of children with hypospadias were exposed during pregnancy to significantly higher levels of PBDEs. The results of this study suggest that level of exposure to PBDEs during gestation may have a role in the etiology of hypospadias.

Formic acid, a novel metabolite of chronic ethanol abuse, causes neurotoxicity, which is prevented by folic acid.

BACKGROUND: Methanol is endogenously formed in the brain and is present as a congener in most alcoholic beverages. Because ethanol is preferentially metabolized over methanol (MeOH) by alcohol dehydrogenase, it is not surprising that MeOH accumulates in the alcohol-abusing population. This suggests that the alcohol-drinking population will have higher levels of MeOH's neurotoxic metabolite, formic acid (FA). FA elimination is mediated by folic acid. Neurotoxicity is a common result of chronic alcoholism. This study shows for the first time that FA, found in chronic alcoholics, is neurotoxic and this toxicity can be mitigated by folic acid administration. OBJECTIVE: To determine if FA levels are higher in the alcohol-drinking population and to assess its neurotoxicity in organotypic hippocampal rat brain slice cultures. METHODS: Serum and CSF FA was measured in samples from both ethanol abusing and control patients, who presented to a hospital emergency department. FA's neurotoxicity and its reversibility by folic acid were assessed using organotypic rat brain hippocampal slice cultures using clinically relevant concentrations. RESULTS: Serum FA levels in the alcoholics (mean +/- SE: 0.416 +/- 0.093 mmol/l, n = 23) were significantly higher than in controls (mean +/- SE: 0.154 +/- 0.009 mmol/l, n = 82) (p < 0.0002). FA was not detected in the controls' CSF (n = 20), whereas it was >0.15 mmol/l in CSF of 3 of the 4 alcoholic cases. Low doses of FA from 1 to 5 mmol/l added for 24, 48 or 72 hours to the rat brain slice cultures caused neuronal death as measured by propidium iodide staining. When folic acid (1 micromol/l) was added with the FA, neuronal death was prevented. CONCLUSIONS: Formic acid may be a significant factor in the neurotoxicity of ethanol abuse. This neurotoxicity can be mitigated by folic acid administration at a clinically relevant dose.

Toxicology: then and now.

Toxicology is "the science of poisons"; more specifically the chemical and physical properties of poisons, their physiological or behavioral effects on living organisms, qualitative, and quantitative methods for their analysis and the development of procedures for the treatment of poisoning. Although the history of poisons dates to the earliest times, the study and the science of toxicology can be traced to Paracelsus (1493-1541) and Orfila (1757-1853). Modern toxicology is characterized by sophisticated scientific investigation and evaluation of toxic exposures. The 20th century is marked by an advanced level of understanding of toxicology. DNA and various biochemicals that maintain cellular functions were discovered. Our level of knowledge of toxic effects on organs and cells is now being revealed at the molecular level. This paper will review the historical progress of clinical and forensic toxicology by exploring analytical techniques in drug analysis, differing biological matrices, clinical toxicology, therapeutic drug management, workplace drug testing, and pharmacodynamic monitoring and pharmacogenetics.

Can venlafaxine in breast milk attenuate the norepinephrine and serotonin reuptake neonatal withdrawal syndrome.

A newborn infant whose mother had used venlafaxine, a selective inhibitor of both norepinephrine and serotonin reuptake, throughout pregnancy exhibited signs consistent with the norepinephrine and serotonin reuptake withdrawal syndrome. Is it possible that mother's milk can help mitigate the effects of norepinephrine and serotonin reuptake withdrawal? Pharmacokinetic analysis and review of the only published case with active treatment of a baby with venlafaxine suggest that breastfeeding may mitigate the neonatal withdrawal syndrome.