Drug interactions with tobacco smoking. An update

Quantification of biological network perturbations for mechanistic insight and diagnostics using two-layer causal models

BACKGROUND

High-throughput measurement technologies such as microarrays provide complex datasets reflecting mechanisms perturbed in an experiment, typically a treatment vs. control design. Analysis of these information rich data can be guided based on a priori knowledge, such as networks or set of related proteins or genes. Among those, cause-and-effect network models are becoming increasingly popular and more than eighty such models, describing processes involved in cell proliferation, cell fate, cell stress, and inflammation have already been published. A meaningful systems toxicology approach to study the response of a cell system, or organism, exposed to bio-active substances requires a quantitative measure of dose-response at network level, to go beyond the differential expression of single genes.

RESULTS

We developed a method that quantifies network response in an interpretable manner. It fully exploits the (signed graph) structure of cause-and-effect networks models to integrate and mine transcriptomics measurements. The presented approach also enables the extraction of network-based signatures for predicting a phenotype of interest. The obtained signatures are coherent with the underlying network perturbation and can lead to more robust predictions across independent studies. The value of the various components of our mathematically coherent approach is substantiated using several in vivo and in vitro transcriptomics datasets. As a proof-of-principle, our methodology was applied to unravel mechanisms related to the efficacy of a specific anti-inflammatory drug in patients suffering from ulcerative colitis. A plausible mechanistic explanation of the unequal efficacy of the drug is provided. Moreover, by utilizing the underlying mechanisms, an accurate and robust network-based diagnosis was built to predict the response to the treatment.

CONCLUSION

The presented framework efficiently integrates transcriptomics data and "cause and effect" network models to enable a mathematically coherent framework from quantitative impact assessment and data interpretation to patient stratification for diagnosis purposes.

Cell culture metabolomics in the diagnosis of lung cancer-the influence of cell culture conditions

Lung cancer is the leading cause of cancer deaths. Unfortunately, lung cancer is often diagnosed only when it becomes symptomatic or at an advanced stage when few treatment options are available. Hence, a diagnostic test suitable for screening widespread populations is required to enable earlier diagnosis. Analysis of exhaled breath provides a non-invasive method for early detection of lung cancer. Analysis of volatile organic compounds (VOCs) by various mass spectral techniques has identified potential biomarkers of disease. Nevertheless, the metabolic origins and the disease specificity of VOCs need further elucidation. Cell culture metabolomics can be used as a bottom-up approach to identify biomarkers of pathological conditions and can also be used to study the metabolic pathways that produce such compounds. This paper summarizes the current knowledge of lung cancer biomarkers in exhaled breath and emphasizes the critical role of cell culture conditions in determining the VOCs produced in vitro. Hypoxic culture conditions more closely mimic the conditions of cancer cell growth in vivo. We propose that since hypoxia influences cell metabolism and so potentially the VOCs that the cancer cells produce, the cell culture metabolomics projects should consider culturing cancer cells in hypoxic conditions.

A phase II study of erlotinib in gemcitabine refractory advanced pancreatic cancer

BACKGROUND

Erlotinib induced skin toxicity has been associated with clinical benefit in several tumour types. This phase II study evaluated the efficacy of erlotinib, dose escalated to rash, in patients with advanced pancreatic cancer previously treated with gemcitabine.

METHODS

Erlotinib was given at an initial dose of 150 mg/day, and the dose was escalated by 50mg every 2 weeks (to a maximum of 300 mg/day) until >grade 1 rash or other dose limiting toxicities occurred. Erlotinib pharmacokinetics were performed, and baseline tumour tissue was collected for mutational analysis and epidermal growth factor receptor (EGFR) expression. The primary end-point was the disease control rate (objective response and stable disease >8 weeks).

RESULTS

Fifty-one patients were accrued, and 49 received treatment. Dose-escalation to 200-300 mg of erlotinib was possible in 9/49 (18%) patients. The most common ⩾ grade 3 adverse events included fatigue (6%), rash (4%) and diarrhoea (4%). Thirty-seven patients were evaluable for response, and the best response was stable disease in 12 patients (32% (95% confidence interval (CI) 17-47%)). Disease control was observed in nine patients (24% (95% CI: 10-38%)). Median survival was 3.8 months, and 6 month overall survival rate was 32% (95% CI 19-47%). Mutational analysis and EGFR expression were performed on 29 patients, with 93% having KRAS mutations, none having EGFR mutations, and 86% expressing EGFR. Neither KRAS mutational status nor EGFR expression was associated with survival.

CONCLUSIONS

Erlotinib dose escalated to rash was well tolerated but not associated with significant efficacy in non-selected patients with advanced pancreatic cancer.

Smoking cessation is followed by increases in serum bilirubin, an endogenous antioxidant associated with lower risk of lung cancer and cardiovascular disease

INTRODUCTION

Lower concentrations of serum bilirubin, an endogenous antioxidant, have been associated with risk of many smoking-related diseases, including lung cancer and cardiovascular disease, and current smokers are reported to have lower bilirubin levels than nonsmokers and past smokers. This study evaluates the effects of smoking cessation on bilirubin levels.

METHODS

In a secondary analysis of a 6-week placebo-controlled trial of naltrexone for smoking cessation, indirect and total bilirubin concentrations were evaluated at baseline and following smoking cessation. Individuals who were continuously abstinent for 6 weeks (n = 155) were compared to those who were not (n = 193). Participants reported smoking ≥ 20 cigarettes daily at baseline and received smoking cessation counseling, 21 mg nicotine patch daily, and either placebo or 1 of 3 doses of naltrexone (25, 50, or 100mg) for 6 weeks. Change in indirect and total bilirubin following the quit date was measured at Weeks 1, 4, and 6 compared to baseline.

RESULTS

Individuals who were continuously abstinent from smoking, independent of naltrexone condition, showed a significantly greater mean increase in indirect (~unconjugated) bilirubin (0.06 mg/dl, SD = 0.165) compared to those who did not (mean = 0.02, SD = 0.148, p = .015). Similar results were obtained for total bilirubin (p = .037).

CONCLUSIONS

Smoking cessation is followed by increases in bilirubin concentration that have been associated with lower risk of lung cancer and cardiovascular disease.

Tobacco use treatment in primary care patients with psychiatric illness

The prevalence of smoking is higher in patients with psychiatric illness compared with the general population. Smoking causes chronic illnesses, which lead to premature mortality in those with psychiatric illness, is associated with greater burden of psychiatric symptoms, and contributes to the social isolation experienced by individuals with psychiatric disorders. Most patients with a psychiatric illness present initially to primary care rather than specialty care settings, and some patients receive care exclusively in the primary care setting. Therefore, family physicians and other primary care clinicians have an important role in the recognition and treatment of tobacco use disorders in patients with psychiatric illnesses. In this article we review common myths associated with smoking and psychiatric illness, techniques for implementing evidence-based tobacco use treatments, the evidence base for tobacco use treatment for patients with specific psychiatric diagnoses, and factors to consider when treating tobacco use disorders in patients with psychiatric illness.

Cilostazol eliminates adverse smoking outcome in patients with drug-eluting stent implantation

BACKGROUND

The present study investigated whether cilostazol can eliminate adverse smoking outcome after percutaneous coronary intervention (PCI).

METHODS AND RESULTS

A total of 914 patients with successful drug-eluting stent (DES) implantation were randomly assigned to dual antiplatelet therapy (DAT; aspirin and clopidogrel, n=457) or to triple antiplatelet therapy (TAT; DAT with cilostazol, n=457). The effect of smoking on 2-year major adverse cardio/cerebrovascular events (MACCE) in both the TAT and DAT groups was evaluated. Total MACCE were not significantly different between the 2 anti-platelet regimens (9.8% in TAT vs. 11.4% in DAT groups, P=0.45), but the adverse effects of smoking on clinical outcome were different between DAT vs. TAT. Current smokers had a higher prevalence of MACCE than non-smokers in the DAT group (16.7% vs. 9.5%, P=0.04). In the TAT group, however, the adverse effect of smoking was abolished (9.2% vs. 10.1%, P=0.85). Regarding the effects of smoking on the antiplatelet effects of DAT or TAT, post-treatment platelet reactivity (in P2Y12 reaction units; PRU) in current smokers was not significantly lower than that in non-smokers in the DAT group, whereas, in the TAT group, it was significantly lower than that of non-smokers (189±88 vs. 216±89 PRU, P=0.01).

CONCLUSIONS

Adverse clinical effects of smoking may be eliminated by the addition of cilostazol to DAT after DES implantation. This may be due to the stimulation of cilostazol's antiplatelet effects by smoking.

Factors affecting the development of adverse drug reactions (Review article)

OBJECTIVES

To discuss the effect of certain factors on the occurrence of Adverse Drug Reactions (ADRs).

DATA SOURCES

A systematic review of the literature in the period between 1991 and 2012 was made based on PubMed, the Cochrane database of systematic reviews, EMBASE and IDIS. Key words used were: medication error, adverse drug reaction, iatrogenic disease factors, ambulatory care, primary health care, side effects and treatment hazards.

SUMMARY

Many factors play a crucial role in the occurrence of ADRs, some of these are patient related, drug related or socially related factors. Age for instance has a very critical impact on the occurrence of ADRs, both very young and very old patients are more vulnerable to these reactions than other age groups. Alcohol intake also has a crucial impact on ADRs. Other factors are gender, race, pregnancy, breast feeding, kidney problems, liver function, drug dose and frequency and many other factors. The effect of these factors on ADRs is well documented in the medical literature. Taking these factors into consideration during medical evaluation enables medical practitioners to choose the best drug regimen.

CONCLUSION

Many factors affect the occurrence of ADRs. Some of these factors can be changed like smoking or alcohol intake others cannot be changed like age, presence of other diseases or genetic factors. Understanding the different effects of these factors on ADRs enables healthcare professionals to choose the most appropriate medication for that particular patient. It also helps the healthcare professionals to give the best advice to patients. Pharmacogenomics is the most recent science which emphasizes the genetic predisposition of ADRs. This innovative science provides a new perspective in dealing with the decision making process of drug selection.

Effects of smoking and alcohol consumption on 5-fluorouracil-related metabolic enzymes in oral squamous cell carcinoma

Lifestyle, particularly smoking and alcohol consumption, may induce and/or inhibit drug metabolism. In order to reveal the effects of smoking and alcohol consumption on the 5-fluorouracil (5-FU)-related metabolic enzymes, namely thymidylate synthase, dihydropyrimidine dehydrogenase (DPD; a sole catabolic enzyme of 5-FU), orotate phosphoribosyl transferase (OPRT) and thymidine phosphorylase, in oral squamous cell carcinomas, the mRNA expression of these enzymes was investigated in 29 surgical specimens and compared by the Brinkman index and drinking years. The surgical specimens were divided into normal and tumor regions and were independently analyzed using quantitative reverse transcription-polymerase chain reaction. There was a significantly positive correlation between DPD mRNA expression in these tissues and Brinkman index/drinking years, with OPRT mRNA expression being significantly correlated to the Brinkman index in tumor tissues. These results revealed that lifestyle habits, including smoking and alcohol consumption, may vary the activity of the 5-FU-related metabolic enzymes. DPD is the initial and rate-limiting enzyme in the catabolic pathway of 5-FU. Therefore, smoking and alcohol consumption may reduce the anticancer activity of 5-FU, possibly through the induction of DPD activity.

Socio-demographic, lifestyle and psychological predictors of benzodiazepine and z-hypnotic use patterns

AIMS

Risk and demographic factors for benzodiazepine and z-hypnotic use are incompletely understood. The aim of the paper was therefore to investigate socio-demographic, lifestyle and psychological factors predicting onset and differential pattern of prescribed benzodiazepine and z-hypnotic use in a Norwegian population sample.

METHODS

This retrospective cohort study obtained socio-demographic, psychological and lifestyle variables from the Nord-Trøndelag Health Study. Information about benzodiazepine prescriptions from the Norwegian prescription database were linked to epidemiological questionnaire data. Benzodiazepine use was classified into single-period, intermittent and chronic use, and high dose use was defined as being prescribed a yearly average above 180 daily defined doses.

RESULTS

Older age, sleep difficulties and smoking were positively associated with all patterns of benzodiazepine use. Male gender was related to a reduced risk of all patterns of use, whereas educational achievement was negatively associated with single-period use. Alcohol consumption, anxiety and tension were positively related to intermittent and chronic use, while exercise was negatively related to chronic use. Smoking, sleep difficulties and old age were positively associated with prescriptions of high benzodiazepine doses, while exercise was associated with lower doses.

CONCLUSIONS

Patterns of prescribed benzodiazepine use are linked to demographic, lifestyle and clinical variables. Non-pharmacological treatment for sleep difficulties and smoking cessation may reduce the risk of chronic benzodiazepine use.

Online comments on smoking bans in psychiatric hospitals units

OBJECTIVE

Individuals with mental health concerns are disproportionately affected by and suffer the negative consequences of tobacco use disorder, perhaps because smoking has historically been part of psychiatry's culture. In the early 1990s, psychiatric inpatient facilities were exempted from U.S. hospital smoking bans, in response to public outcry with national media attention. Almost 2 decades later, the current study characterizes online conversation about psychiatric hospital smoking bans. Previous commenting studies have demonstrated commenting's negativity, documenting the "nasty effect" wherein negative comments color perceptions of neutral articles. Thus, we focused particular attention on cited barriers to implementing health-positive smoke-free policies.

METHODS

We collected online comments (N = 261) responding to popular media articles on smoking bans in inpatient psychiatry between 2013 and 2014 and conducted an inductive and exploratory qualitative content analysis.

RESULTS

Verifying previous studies documenting the prevalence of negative commenting, of the comments explicitly supporting or refuting psychiatry smoking bans, there were over twice as many con comments (n = 44) than pro (n = 18). Many commenters argued for access to outdoor smoking areas and warned of patient agitation and risk posed to care workers. Identified content themes included psychiatric medication and negative side effects, broken mental health systems and institutions, denigration of the health risks of tobacco in the context of mental illness, typical pro-smoking arguments about "smokers' rights" and alternatives (including e-cigarettes), addiction, and stigma.

CONCLUSIONS

The current findings provide a platform to begin to understand how people talk about mental health issues and smoking. Our analysis also raised complex issues concerning forces that impact U.S. patients with serious mental illness but over which they have little control, including medication, the U.S. health system, stigma, perceptions that life with chronic serious mental illness is not worth living, and psychological and physical pain of coping with mental illness. In consideration of identified barriers raised in opposition to smoking bans in inpatient psychiatry, efforts should emphasize patient stakeholder involvement; patient, visitor, and staff protection from smoke exposure; the effectiveness of nicotine replacement for managing withdrawal; and the lack of evidence that cigarettes are therapeutic.

Nicotine-Cadmium Interaction Alters Exploratory Motor Function and Increased Anxiety in Adult Male Mice

In this study we evaluated the time dependence in cadmium-nicotine interaction and its effect on motor function, anxiety linked behavioural changes, serum electrolytes, and weight after acute and chronic treatment in adult male mice. Animals were separated randomly into four groups of n = 6 animals each. Treatment was done with nicotine, cadmium, or nicotine-cadmium for 21 days. A fourth group received normal saline for the same duration (control). Average weight was determined at 7-day interval for the acute (D1-D7) and chronic (D7-D21) treatment phases. Similarly, the behavioural tests for exploratory motor function (open field test) and anxiety were evaluated. Serum electrolytes were measured after the chronic phase. Nicotine, cadmium, and nicotine-cadmium treatments caused no significant change in body weight after the acute phase while cadmium-nicotine and cadmium caused a decline in weight after the chronic phase. This suggests the role of cadmium in the weight loss observed in tobacco smoke users. Both nicotine and cadmium raised serum Ca²⁺ concentration and had no significant effect on K⁺ ion when compared with the control. In addition, nicotine-cadmium treatment increased bioaccumulation of Cd²⁺ in the serum which corresponded to a decrease in body weight, motor function, and an increase in anxiety.

Electronic cigarettes in smoking cessation

Background: Tobacco use is the most prevalent preventable cause of death in the United States, accounting for approximately 20% of all deaths each year. Despite available treatment options, many smokers still experience multiple failed quit attempts indicating a need for development of novel therapies. When the electronic cigarette (e-cigarette) was introduced to the United States' market in 2007, patients began to discuss its possible use as the newest form of nicotine replacement therapy (NRT).

Methods: A PubMed search was performed for the following terms: “Electronic cigarettes, e-cigarettes, and smoking cessation”. A manual search of references from articles found was performed to identify additional relevant articles.

Results: Most evidence surrounding use of e-cigarettes for smoking cessation is found in self-reports and user surveys. One study looking at short-term effects of e-cigarettes on desire to smoke found a decreased desire in subjects inhaling from both nicotine-containing and placebo e-cigarettes. Three studies from Italy looked at natural reduction of cigarette use when subjects were allowed to freely use e-cigarettes. All three studies showed a natural reduction indicating potential efficacy for e-cigarette use in smoking cessation. A recently published randomized controlled trial was unable to prove superiority of e-cigarettes over transdermal nicotine patches for smoking cessation.

Conclusions: A few studies have explored the possibility of replacing tobacco cigarettes with e-cigarettes to facilitate a natural reduction in use and have shown minimal positive results in a population not intending to quit. A recent randomized controlled trial comparing e-cigarettes with nicotine patches for smoking cessation was unable to prove superiority. Until these products are regulated and efficacy can be shown with well-designed studies, e-cigarettes are not a viable treatment for use in smoking cessation or as nicotine replacement therapy.

Impact of smoking on long-term outcomes in patients with atherosclerotic vascular disease treated with aspirin or clopidogrel: insights from the CAPRIE trial (Clopidogrel Versus Aspirin in Patients at Risk of Ischemic Events)

OBJECTIVES

The goal of this study was to investigate the differential efficacy of clopidogrel or aspirin monotherapy according to smoking status in patients with atherosclerotic vascular disease.

BACKGROUND

Smoking enhances clopidogrel-induced platelet inhibition, which may explain the higher relative benefit among smokers observed in trials evaluating dual antiplatelet therapy. Whether smoking has an impact on clinical outcomes in patients requiring a single antiplatelet agent remains unknown.

METHODS

This was a post-hoc analysis of the CAPRIE (Clopidogrel Versus Aspirin in Patients at Risk of Ischemic Events) trial that compared clopidogrel and aspirin monotherapy in patients (N = 19,184) with atherosclerotic vascular disease.

RESULTS

Current smokers (n = 5,688) had an increased risk of ischemic events compared with never smokers (n = 4,135; hazard ratio [HR]: 1.24 [95% confidence interval (CI): 1.08 to 1.42]) and ex-smokers (n = 9,381; HR: 1.32 [95% CI: 1.18 to 1.47]) (p < 0.001). Clopidogrel was associated with a reduction in ischemic events among current smokers (8.3% vs. 10.8%; HR: 0.76 [95% CI: 0.64 to 0.90]), whereas no benefit over aspirin was seen in the combined group of ex-smokers/never-smoked patients (10.4% vs. 10.6%; HR: 0.99 [95% CI: 0.89 to 1.10]; p = 0.01 for interaction). Among current smokers, clopidogrel also reduced myocardial infarction, vascular death, and death from any cause compared with aspirin. No interaction between smoking status and study treatment was observed for bleeding events.

CONCLUSIONS

In a post-hoc analysis of the CAPRIE population, current smokers appeared to have enhanced benefit with clopidogrel therapy for secondary prevention compared with aspirin. These results should be considered hypothesis generating for future prospective studies assessing the impact of specific platelet-inhibiting strategies according to smoking status.

Clinical management of tobacco dependence in inpatient psychiatry: provider practices and patient utilization

OBJECTIVE

This investigation examined predictors of utilization of nicotine replacement therapy (NRT) during a smoke-free psychiatric hospitalization.

METHODS

Smokers (N=324) were recruited from smoke-free adult inpatient psychiatric units. Exploratory analyses examined correlates of NRT provision and utilization.

RESULTS

The prevalence of NRT use was 51% overall and was greater among patients offered NRT on admission (58%) versus later (34%), among patients with more severe depression and nicotine withdrawal, and among those who reported perceptions that NRT decreases nicotine withdrawal, provides a nicotine substitute, and helps with quitting smoking (p<.05, all comparisons). Although the ratio of nicotine patch dose to usual cigarettes per day was 1.2±.7, the ratio was negatively correlated with time to first cigarette (Spearman's ρ=-.30, p<.01), suggesting potential underdosing of more dependent smokers.

CONCLUSIONS

During smoke-free psychiatric hospitalizations, clinical management of nicotine withdrawal may be enhanced by offering patients NRT directly on admission, educating patients on the benefits of NRT, and increasing the dosage for more dependent smokers.

Allostatic load as a tool for monitoring physiological dysregulations and comorbidities in patients with severe mental illnesses

Severe mental illnesses like schizophrenia and bipolar disorder are disabling, chronic conditions that are often accompanied by medical comorbidities. In this theoretical article, we review the allostatic load model representing the "wear and tear" that chronic stress exacts on the brain and body. We propose an innovative way of monitoring physical and psychiatric comorbidities by integrating the allostatic load model into clinical practice. By interpreting peripheral biomarkers differently, medical professionals can calculate a simple, count-based, allostatic load index known to predict diverse stress-related pathologies. In addition to screening for comorbidities, allostatic load indices can be used to monitor the effects of pharmacological and psychosocial interventions. This framework can also be used to generate a dialogue between patient and practitioner to promote preventive and proactive approaches to health care.

Pharmacogenomics of anti-platelet and anti-coagulation therapy

Arterial thrombosis is a major component of vascular disease, especially myocardial infarction (MI) and stroke. Current anti-thrombotic therapies such as warfarin and clopidogrel are effective in inhibiting cardiovascular events; however, there is great inter-individual variability in response to these medications. In recent years, it has been recognized that genetic factors play a significant role in drug response, and, subsequently, common variants in genes responsible for metabolism and drug action have been identified. These discoveries along with new diagnostic targets and therapeutic strategies hold promise for more effective individualized anti-coagulation and anti-platelet therapy.

Smoking cessation in lung cancer-achievable and effective

BACKGROUND

Lung cancer is the leading cause of death from cancer in Germany. 90% of cases are due to the inhalation of tobacco smoke. About 40% of patients with newly diagnosed lung cancer are still smokers. A structured smoking cessation program is medically reasonable in this situation but is only rarely offered.

METHODS

This review is based on a selective search in the PubMed database combined with a manual search for current publications.

RESULTS

Many cross-sectional and longitudinal studies have shown that patients with lung cancer benefit from smoking cessation. After resection with curative intent, second tumors are 2.3 times more common, and recurrent tumors 1.9 times more common, in patients who continue to smoke than in those who stop. The overall mortality in smokers is 2.9 times higher. Smoking cessation also lowers the rate of radiation pneumonitis and infection during radiotherapy and prolongs the median survival after chemoradiotherapy for small-cell lung cancer (18.0 vs. 13.6 months). For patients with non-small-cell lung cancer, smoking cessation is associated with a better general state of health (77.5% vs. 57.6%). For the many patients with lung cancer who are treated palliatively, smoking cessation offers the advantages of improved pulmonary function, weight gain, and better overall quality of life.

CONCLUSION

Smoking cessation in patients with lung cancer is an important means of increasing the efficacy of treatment and improving their quality of life.

Coffee and caffeine intake and incidence of type 2 diabetes mellitus: a meta-analysis of prospective studies

PURPOSE

Coffee and caffeine have been linked to type 2 diabetes mellitus (T2DM). A dose-response meta-analysis of prospective studies was conducted to assess the association between coffee and caffeine intake and T2DM incidence.

METHODS

Pertinent studies were identified by a search of PubMed and EMBASE. The fixed- or random-effect pooled measure was selected based on between-study heterogeneity. Dose-response relationship was assessed by restricted cubic spline.

RESULTS

Compared with the lowest level, the pooled relative risk (95 % CI) of T2DM was 0.71 (0.67-0.76) for the highest level of coffee intake (26 articles involving 50,595 T2DM cases and 1,096,647 participants), 0.79 (0.69-0.91) for the highest level of decaffeinated coffee intake (10 articles involving 29,165 T2DM cases and 491,485 participants) and 0.70 (0.65-0.75) for the highest level of caffeine intake (6 articles involving 9,302 T2DM cases and 321,960 participants). The association of coffee, decaffeinated coffee and caffeine intake with T2DM incidence was stronger for women than that for men. A stronger association of coffee intake with T2DM incidence was found for non-smokers and subjects with body mass index <25 kg/m(2). Dose-response analysis suggested that incidence of T2DM decreased by 12 % [0.88 (0.86-0.90)] for every 2 cups/day increment in coffee intake, 11 % [0.89 (0.82-0.98)] for every 2 cups/day increment in decaffeinated coffee intake and 14 % [0.86 (0.82-0.91)] for every 200 mg/day increment in caffeine intake.

CONCLUSIONS

Coffee and caffeine intake might significantly reduce the incidence of T2DM.

Nicotine increases survival in human colon cancer cells treated with chemotherapeutic drugs

Cigarette smoking is implicated in the development of colon cancer. Furthermore, nicotine increases cell proliferation and inhibits apoptosis through α7-nicotinic acetylcholine receptor (α7-nAChR) activation in human colon carcinoma cells. An open issue is whether nicotine interfere with colorectal cancer pharmacological treatment, by inhibiting drug-mediated apoptosis. To assess this hypothesis, we evaluated nicotine effect on Caco-2 and HCT-8 colon cancer cells, treated with 5-Fluorouracil (5-FU) and Camptothecin (CPT), chemotherapeutics commonly utilized as adjuvant treatment of colon cancer. Nicotine decreased anti-proliferative and pro-apoptotic effects exerted by chemotherapeutics on both cell lines. These effects partially reverted by exposure to α-bungarotoxin (α-BTX), an inhibitor of α7-nAChR. Nicotine addition to Caco-2 and HCT-8, treated with 5-FU or CPT, decreased the cleavage of substrate of caspase 3 and 7, poly-ADP-ribose polymerase (PARP). Moreover, P-ERK/ERK ratio was modified by nicotine addition to 5-FU and CPT treated cells in an opposite manner. However, when co-administrating PD98059, an ERK phosphorylation inhibitor, an increased apoptosis was observed. In Caco-2 and HCT-8 nicotine reverted 5-FU and CPT apoptotic effects through AKT phosphorylation, as demonstrated by apoptotic increase in presence of LY294002, an AKT phosphorylation inhibitor. Nicotine interfered with colorectal cancer pharmacological treatment in vitro by inhibiting apoptosis induced by chemotherapeutic drugs. Nicotine anti-apoptotic effects were exerted through ERK and AKT pathway activation.

Cigarette smoking and gemcitabine-induced neutropenia in advanced solid tumors

BACKGROUND

Chemotherapy-associated neutropenia has been reported to be a pharmacodynamic marker of response in some advanced solid tumors. Factors that accelerate drug clearance lead to lower plasma concentrations and toxicity, including neutropenia. Smoking accelerates the metabolism of several drugs, including chemotherapy. We sought to study the effects of smoking on gemcitabine-induced neutropenia in this retrospective study.

METHODS

Smoking status and neutropenia along with other clinical parameters were recorded in 151 patients receiving first-line gemcitabine-based chemotherapy for advanced solid tumors.

RESULTS

Tumor types included breast (9.3%), lung (4.6%), pancreatobiliary (70.9%), or other/unknown primary cancer (15.2%). Logistic regression showed that never smokers had increased neutropenia versus current smokers (odds ratio: 3.5; 95% confidence interval, CI: 1.1-11.4). A 5-unit increase in pack-years reduced the odds of having higher neutropenia toxicity by 6.3% (95% CI 12 to 1%; p = 0.036).

CONCLUSION

Smokers had less neutropenia than nonsmokers, a finding that was more pronounced with increasing pack-years. This pharmacodynamic marker of gemcitabine-induced neutropenia may result in less efficacy of gemcitabine. Future prospective trials should correlate smoking, metabolizing phenotype, neutropenia, and response to gemcitabine therapy.

Breath tests in respiratory and critical care medicine: from research to practice in current perspectives

Today, exhaled nitric oxide has been studied the most, and most researches have now focused on asthma. More than a thousand different volatile organic compounds have been observed in low concentrations in normal human breath. Alkanes and methylalkanes, the majority of breath volatile organic compounds, have been increasingly used by physicians as a novel method to diagnose many diseases without discomforts of invasive procedures. None of the individual exhaled volatile organic compound alone is specific for disease. Exhaled breath analysis techniques may be available to diagnose and monitor the diseases in home setting when their sensitivity and specificity are improved in the future.

Tobacco use and its treatment among young people in mental health settings: a qualitative analysis

BACKGROUND

Youth with psychiatric disorders are at increased risk of tobacco use. Outpatient mental health settings have received little investigation for delivering tobacco treatment. This study obtained formative data to guide development of a tobacco cessation program for transitional age youth with co-occurring psychiatric disorders with a focus on outpatient mental health settings.

METHODS

Applying qualitative methods, we analyzed transcripts from interviews with 14 mental health clients (aged 16-23) and 8 mental health providers.

RESULTS

The youth identified internal (nicotine addiction and mood), social, parental, and media influences to their use of tobacco. Providers' viewed youth tobacco use as a normative developmental process, closely tied to management of psychiatric symptoms, supported by parents, and of lower priority relative to youth alcohol and illicit drug use. Youth and providers believed that clinicians can do more to address tobacco use in practice and emphasized nonjudgmental support and nondirective approaches. Top recommended quitting strategies, however, differed notably for the youth (cold turkey, support from friends, physical activity, hobbies) and providers (cessation pharmacotherapy, cessation groups, treatment referrals).

CONCLUSIONS

Mental health providers' greater prioritization of other substances and view of youth smoking as developmentally normative and a coping strategy for psychopathology are likely contributing to the general lack of attention to tobacco use currently. Integrating care within mental health settings would serve to reach youth in an arena where clinical rapport is already established, and study findings suggest receptivity for system improvements. Of consideration, however, is the apparent disconnect between provider and youth recommended strategies for supporting cessation.

Quercetin suppressed CYP2E1-dependent ethanol hepatotoxicity via depleting heme pool and releasing CO

Naturally occuring quercetin protects hepatocytes from ethanol-induced oxidative stress, and heme oxygenase-1 (HO-1) induction and carbon monoxide (CO) metabolite may be implicated in the beneficial effect. However, the precise mechanism by which quercetin counteracts CYP2E1-mediated ethanol hepatotoxicity through HO-1 system is still remained unclear. To explore the potential mechanism, herein, ethanol (4.0 g/kg.bw.) was administrated to rats for 90 days. Our data showed that chronic ethanol over-activated CYP2E1 but suppressed HO-1 with concurrent hepatic oxidative damage, which was partially normalized by quercetin (100mg/kg.bw.). Quercetin (100 μM) induced HO-1 and depleted heme pool when incubated to human hepatocytes. Ethanol-stimulated (100mM) CYP2E1 upregulation was suppressed by quercetin but further enhanced by HO-1 inhibition with resultant heme accumulation. CO scavenging blocked the suppression of quercetin only on CYP2E1 activity. CO donor dose-dependently inactivated CYP2E1 of ethanol-incubated microsome, which was mimicked by HO-1 substrate but abolished by CO scavenger. Thus, CYP2E1-mediated ethanol hepatotoxicity was alleviated by quercetin through HO-1 induction. Depleted heme pool and CO releasing limited protein synthesis and inhibited enzymatic activity of CYP2E1, respectively.

The impact of smoking on clinical efficacy and pharmacodynamic effects of clopidogrel: a systematic review and meta-analysis

CONTEXT

Previous findings regarding the relationship between smoking and clopidogrel effects were considerably discrepant.

OBJECTIVE

To assess the impact of smoking on clinical and pharmacodynamic response to clopidogrel.

DATA SOURCES

Medline, EMBASE and the Cochrane Library through January 2013 were searched. Reference lists of pertinent literatures and abstracts of major cardiovascular conferences were screened.

STUDY SELECTION

Clinical and laboratory studies, which reported major adverse cardiovascular events and on-clopidogrel platelet reactivity categorised by smoking status respectively, were selected.

DATA EXTRACTION

Descriptive and quantitative data were extracted. The main analyses were performed under a random-effects model. For clinical studies, HR estimates were synthesised according to smoking status; for laboratory studies, standardised mean difference (SMD) of on-clopidogrel platelet reactivity and OR for high on-clopidogrel platelet reactivity were pooled. Heterogeneity was quantified by computing I(2) statistic.

RESULTS

Of the 1869 citations retrieved, seven clinical studies and 12 laboratory studies involving 111 132 patients with established cardiovascular disease and 6658 patients with acute coronary syndrome and/or stent deployment, respectively, were included for meta-analysis. Pooled clinical results showed that an intensified antiplatelet regimen involving clopidogrel was associated with 10% reduced risk for major adverse cardiovascular events among non-current smokers (HR 0.90; 95% CI 0.85 to 0.96), while this clinical benefit was enhanced by 2.9-fold among current smokers (HR 0.71; 95% CI 0.62 to 0.80). Pooled analysis of laboratory studies revealed that current smokers had significantly lower on-clopidogrel platelet reactivity (SMD -0.30; 95% CI -0.46 to -0.15) but, notably, there was considerable inter-study heterogeneity (I(2) 76.2%; p=0.000). The analysis based on four studies (n=1423) suggested a significantly lower odds of high on-clopidogrel platelet reactivity among current smokers than those among never smokers (OR 0.33; 95% CI 0.22 to 0.43).

CONCLUSIONS

Smoking appears to positively modify the relative clinical efficacy and pharmacodynamic effects of clopidogrel.

Considering CYP1A2 phenotype and genotype for optimizing the dose of olanzapine in the management of schizophrenia

INTRODUCTION

Schizophrenia, a mental disorder, is a debilitating condition which typically strikes young people in their early 20's. Antipsychotic medications are widely prescribed for the treatment of schizophrenia however a balancing act is necessary to provide the correct dose to each patient. It is suggested that a large number of patients discontinue antipsychotic pharmacotherapy because the treatments provided do not always reduce the positive symptoms of the disease, while many have adverse effects on the patients. This implies that neither the incorrect drug nor the optimal dosage for that patient is achieved.

AREAS COVERED

The current review investigates variability in response to olanzapine with a specific focus on the common intrinsic and extrinsic factors that influence both olanzapine and CYP1A2 activity. Furthermore, the authors discuss the utilization of phenotyping and genotyping of CYP1A2 and their potential utility in clinical practice for olanzapine dosing regimens. The authors also consider the potential of pharmacometrics compared to pharmacogenomics as a tool to personalize medicine.

EXPERT OPINION

Careful consideration must be given to the impact of a genetic variant on the disposition of a drug prior to implementing genetic 'tests' to determine response. CYP1A2 phenotypic assessment can yield important information regarding the disposition of olanzapine; however, it relies on the accuracy of the metric and the minimal impact of other metabolic pathways. The application of pharmacometrics provides an effective method to establish covariates that significantly influence olanzapine disposition which can incorporate phenotype and/or genotype.

Single-Dose Pharmacokinetics of Varenicline, a Selective Nicotinic Receptor Partial Agonist, in Healthy Smokers and Nonsmokers

Varenicline is a novel and selective alpha4beta2 nicotinic receptor partial agonist that is under development for smoking cessation. The primary objectives of this double-blind, placebo-controlled, single-dose, dose-escalation study were to determine the clinical pharmacology of single doses of varenicline in healthy smokers and nonsmokers under fed and fasted conditions and to determine the clinical pharmacology of varenicline administered in the morning and in the evening to smokers. Within each subject group, 4 subjects were randomized to varenicline and 2 subjects to placebo. Subjects received one single oral administration of varenicline or placebo: 6 doses (0.01, 0.03, 0.1, 0.3, 1.0, and 3.0 mg) were investigated in nonsmokers and 7 doses in smokers (0.01, 0.03, 0.1, 0.3, 1.0, 3.0, and 10.0 mg). Varenicline was well tolerated after single doses up to 3.0 mg in smokers and 1.0 mg in nonsmokers. Nausea and vomiting at doses above 3.0 mg in smokers and 1.0 mg in nonsmokers were dose limiting. Systemic exposure to varenicline and pharmacokinetic variability were similar between smokers and nonsmokers. Coadministration with food, smoking restriction, and time-of-day dosing did not affect the pharmacokinetics of varenicline.

Genetic interaction between NAT2, GSTM1, GSTT1, CYP2E1, and environmental factors is associated with adverse reactions to anti-tuberculosis drugs

BACKGROUND

Adverse drug reactions (ADRs) associated with anti-tuberculosis (anti-TB) drug regimens have considerable impact on anti-TB treatment, potentially leading to unsuccessful outcomes. Nevertheless, the risk factors that play a role in anti-TB drug-induced ADRs are not well established. It is well documented that genetic polymorphisms in drug-metabolizing enzymes (DMEs) result in considerably complex variability in anti-TB drug disposition. In addition, the impact of pharmacogenetic variation on the metabolism of anti-TB drugs may be modifiable by environmental exposure. Thus, an assessment of pharmacogenetic variability combined with biomarkers of environmental exposure may be helpful for demonstrating the effect of the gene-environment interaction on susceptibility to ADRs induced by anti-TB drug therapy.

OBJECTIVE

The aim of the study was to investigate the impact of the interaction between environmental risk factors and pharmacogenetic polymorphisms in four common DMEs--N-acetyltransferase 2 (arylamine N-acetyltransferase) [NAT2], glutathione S-transferase theta 1 [GSTT1], glutathione S-transferase mu 1 [GSTM1], and cytochrome P450 2E1 [CYP2E1]--on commonly reported ADRs to first-line anti-TB drugs in 129 patients receiving homogeneous TB treatment.

METHODS

TB patients monitored during drug treatment were divided into subgroups according to the presence or absence of ADRs. Additionally, the patients' clinical and demographic characteristics were collected in order to identify the environmental factors that are potential triggers for ADRs induced by anti-TB drug treatment. Pharmacogenetic variability was determined by gene sequencing, TaqMan® assays, or polymerase chain reaction.

RESULTS

The findings of this study suggest that the NAT2 slow acetylator haplotype, female sex, and smoking are important determinants of susceptibility to ADRs induced by anti-TB drugs. Patients carrying multiple, but not single, polymorphisms in the NAT2, GSTM1, GSTT1, and CYP2E1 genes were found to have an increased risk of ADRs, as revealed by gene-gene interaction analysis. Moreover, we also identified meaningful gene-environment interaction models that resulted in the highest levels of ADR risk.

CONCLUSION

The study findings provide evidence of the clinical impact of the interaction between pharmacogenetic variability and environmental factors on ADRs induced by anti-TB drug therapy. Predictive pharmacogenetic testing and a comprehensive clinical history would therefore be helpful for identification and careful monitoring of patients at high risk of this complication.

Distinguishing features of cancer patients who smoke: pain, symptom burden, and risk for opioid misuse

Although many cancer patients who have pain are smokers, the extent of their symptom burden and risk for opioid misuse are not well understood. In this study we analyzed records of patients being treated for cancer pain, 94 of whom were smokers and 392 of whom were nonsmokers, to determine smoking status group differences. Smokers had significantly higher pain intensity, fatigue, depression, and anxiety than nonsmokers (independent samples t-tests P < .002). Smokers were at higher risk for opioid misuse based on the short form of the Screener and Opioid Assessment for Patients with Pain (SOAPP). Specifically, smokers had more frequent problems with mood swings, taking medications other than how they are prescribed, a history of illegal drug use, and a history of legal problems (chi-square tests P ≤ .002). Changes in pain and opioid use were examined in a subset of patients (146 nonsmokers and 46 smokers) who were receiving opioid therapy on at least 2 of the 3 data time points (consult, follow-up 1 month after consult, follow-up 6 to 9 months after consult). Results based on multilevel linear modeling showed that over a period of approximately 6 months, smokers continued to report significantly higher pain than nonsmokers. Both smokers and nonsmokers reported a significant decline in pain across the 6-month period; the rate of decline did not differ across smokers and nonsmokers. No significant difference over time was found in opioid use between smokers and nonsmokers. These findings will guide subsequent studies and inform clinical practice, particularly the relevancy of smoking cessation.

PERSPECTIVE

This article describes pain, symptom burden, and risk for opioid misuse among cancer patients with pain across smoking status. Smoking appears to be a potential mechanism for having an increased pain and symptom burden and risk for opioid misuse. This improved understanding of cancer pain will inform clinical practice.

Tobacco smoking among people living with a psychotic illness: the second Australian Survey of Psychosis

OBJECTIVE

The aims of this study were to (a) describe patterns of tobacco smoking among Australians living with a psychotic illness and (b) explore the association between smoking and measures of psychopathology, psychiatric history, psychosocial functioning, physical health, substance use and demographic characteristics.

METHODS

Data were from 1812 participants in the 2010 Australian Survey of High Impact Psychosis. Participants were aged 18-64 years and resided in seven mental health catchment sites across five states of Australia. Bivariate statistics were used to compare smokers with non-smokers on the measures of interest, and to compare ICD-10 diagnostic categories on measures of smoking prevalence, nicotine addiction and quitting history. Multivariate logistic regression was used to test whether (a) demographics and psychiatric history were associated with having ever smoked and (b) whether symptoms and psychosocial functioning were independently associated with current smoking, after controlling for demographics, psychiatric history and substance use.

RESULTS

The prevalence of current tobacco smoking was 66.6% (72% of men and 59% of women); lifetime prevalence was 81%. In univariate analyses, individuals with a diagnosis of schizophrenia or schizoaffective disorder were most likely to be smoking tobacco (70%) and were more nicotine dependent. Smokers reported worse perceived physical health, lower body mass index and waist circumference, and more lifetime medical conditions. A younger age of illness onset, male gender and low education were associated with having ever smoked. Associations with current smoking included low education, male gender, no formal employment, worse negative symptoms, higher daily caffeine consumption, and alcohol dependence and substance abuse/dependence.

CONCLUSIONS

The prevalence of tobacco smoking is high amongst people with a psychotic disorder, and is associated with adverse mental health symptoms as well as high rates of other substance use, poorer subjective physical health, and a higher risk of the many known health consequences of smoking.

Sequential behavioral treatment of smoking and weight control in bipolar disorder

People with severe mental illnesses like schizophrenia and bipolar disorder (BPAD) live significantly shorter lives than people in the general population and most commonly die of cardiovascular disease (CVD). CVD risk behaviors such as smoking are not routinely assessed or assertively treated among people with a severe mental illness. This article provides an illustrative case example of a woman with BPAD who is motivated to quit smoking, despite concerns about weight gain and relapse to depression. It outlines key considerations and describes the patient's experience of participating in a behavioral intervention focussing first on smoking, then diet and physical activity. Clinical challenges encountered during treatment are discussed in the context of relevant literature. These include motivational issues, relapse to depression, medication interactions, weight gain, addressing multiple health behavior change, focussing on a behavioral rather than cognitive approach, collaborating with other health care providers, and gender issues.

Might cigarettes be a "smoking gun" to reduce taxane myelotoxicity?

de Graan and colleagues report a retrospective study of the effects of cigarette smoking on taxane pharmacokinetics and myelosuppression. There was no difference in taxane pharmacokinetic clearance between smokers and nonsmokers. Further prospective studies of the effects of cigarette smoking on myelosuppression would be of interest.

Clinically significant psychotropic drug-drug interactions in the primary care setting

In recent years, the growing numbers of patients seeking care for a wide range of psychiatric illnesses in the primary care setting has resulted in an increase in the number of psychotropic medications prescribed. Along with the increased utilization of psychotropic medications, considerable variability is noted in the prescribing patterns of primary care providers and psychiatrists. Because psychiatric patients also suffer from a number of additional medical comorbidities, the increased utilization of psychotropic medications presents an elevated risk of clinically significant drug interactions in these patients. While life-threatening drug interactions are rare, clinically significant drug interactions impacting drug response or appearance of serious adverse drug reactions have been documented and can impact long-term outcomes. Additionally, the impact of genetic variability on the psychotropic drug's pharmacodynamics and/or pharmacokinetics may further complicate drug therapy. Increased awareness of clinically relevant psychotropic drug interactions can aid clinicians to achieve optimal therapeutic outcomes in patients in the primary care setting.

Using bioinformatic approaches to identify pathways targeted by human leukemogens

We have applied bioinformatic approaches to identify pathways common to chemical leukemogens and to determine whether leukemogens could be distinguished from non-leukemogenic carcinogens. From all known and probable carcinogens classified by IARC and NTP, we identified 35 carcinogens that were associated with leukemia risk in human studies and 16 non-leukemogenic carcinogens. Using data on gene/protein targets available in the Comparative Toxicogenomics Database (CTD) for 29 of the leukemogens and 11 of the non-leukemogenic carcinogens, we analyzed for enrichment of all 250 human biochemical pathways in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The top pathways targeted by the leukemogens included metabolism of xenobiotics by cytochrome P450, glutathione metabolism, neurotrophin signaling pathway, apoptosis, MAPK signaling, Toll-like receptor signaling and various cancer pathways. The 29 leukemogens formed 18 distinct clusters comprising 1 to 3 chemicals that did not correlate with known mechanism of action or with structural similarity as determined by 2D Tanimoto coefficients in the PubChem database. Unsupervised clustering and one-class support vector machines, based on the pathway data, were unable to distinguish the 29 leukemogens from 11 non-leukemogenic known and probable IARC carcinogens. However, using two-class random forests to estimate leukemogen and non-leukemogen patterns, we estimated a 76% chance of distinguishing a random leukemogen/non-leukemogen pair from each other.

A dose-response meta-analysis of coffee consumption and bladder cancer

BACKGROUND

A number of studies have examined the association between coffee consumption and risk of bladder cancer, but uncertainty about the dose-response relationship remains.

MATERIALS AND METHODS

A comprehensive search was performed to identify all observational studies providing quantitative estimates between bladder cancer risk and coffee consumption. Dose-response relationship was assessed by restricted cubic spline model and bivariate random-effect meta-regression.

RESULTS

23 case-control studies with 7690 cases and 13,507 controls, and 5 cohort studies with 700 cases and 229,099 participants, met the inclusion criteria. Compared with non-drinkers and for case-control studies, the pooled smoking-adjusted RRs(95% CI) of bladder cancer were 1.07(1.02-1.13) for 1 cup/day, 1.15(1.05-1.26) for 2 cups/day, 1.22(1.08-1.38) for 3 cups/day, and 1.29(1.12-1.48) for 4 cups/day. For cohort studies, the pooled smoking-adjusted RRs of bladder cancer were 1.09(95% CI, 0.89-1.34) for 1 cup/day, 1.13(95% CI, 0.82-1.55) for 2 cups/day, 1.09(95% CI, 0.77-1.56) for 3 cups/day, and 1.01(95% CI, 0.69-1.48) for 4 cups/day.

CONCLUSIONS

Although data from case-control studies suggested that coffee was a risk factor for bladder cancer, there was no conclusive evidence on this association because of inconsistencies between case-control and cohort studies.

Cetuximab-induced skin reactions are suppressed by cigarette smoking in patients with advanced colorectal cancer

BACKGROUND

Smoking is widely accepted as the most important risk factor for cancer in the modern world. Several constituents of cigarette smoke are known to interact with drug-metabolizing enzymes, potentially affecting the outcomes of drug treatment. Cetuximab (Erbitux(®); Merck Serono) is indicated for the treatment of colorectal cancer with respect to restoring chemosensitivity to irinotecan in irinotecan-resistant patients. The purpose of this study was to determine whether cigarette smoking adversely affects the actions of cetuximab in the treatment of colorectal cancer.

METHODS

We studied 56 patients with colorectal cancer who were treated with cetuximab in our hospital during the time period from 2009 through 2010. We compared the adverse reaction rates of 16 patients who smoked (smokers) with those of 38 patients who did not smoke (non-smokers, including 16 patients who never smoked and 22 patients who were former smokers).

RESULTS

The incidence of skin reactions after cetuximab treatment was lower in the smokers than in the non-smokers. In addition, the incidence of anorexia was higher in the smokers than in the non-smokers. Within the group of non-smokers, no statistically significant differences were observed between the never smokers and the former smokers with regard to adverse reactions.

CONCLUSION

Our findings suggest that cigarette smoking during anticancer treatment with cetuximab-based regimens reduces the skin reaction, which leads to a reduction in the benefit of the treatment; therefore, patients should quit smoking, at least while receiving cetuximab-based treatment.

Prediction of drug response and safety in clinical practice

Many clinicians hoped that the completion of the Human Genome Project would result in "individualized drug therapy," i.e., determining the right medication at the right dose 100% of the time based upon the individual's genetics. The pharmacogenomic prediction of drug efficacy and safety has not become a reality due to continuing realization of the complexity dictating the human-drug interaction. New methods of metabolomics, proteomics, and transcriptomics that account for this complexity hold promise for translational researchers hoping to increase drug efficacy and decrease drug toxicity.

Cigarette smoking, coffee drinking, and ingestion of charcoal-broiled beef as potential modifiers of drug therapy and confounders of clinical trials

A pathway of research is described, leading from the finding of an inhibitory effect of 3-methylcholanthrene on the carcinogenicity of an aminoazo dye, to the induction of drug-metabolizing enzymes by 3-methylcholanthrene, benzo[a]pyrene, and other polycyclic aromatic hydrocarbons, to the demonstration of enhanced drug metabolism in cigarette smokers, coffee drinkers, and people who eat charcoal-broiled beef. The results of these studies indicate that cigarette smoking, coffee drinking, and the ingestion of charcoal-broiled beef (all resulting in exposure to polycyclic aromatic hydrocarbons) can influence the dosing regimen needed for proper drug therapy and are potential confounders of clinical trials with drugs metabolized by polycyclic aromatic hydrocarbon-inducible enzymes.

Urinary concentrations of benzophenone-type UV filters in U.S. women and their association with endometriosis

Benzophenone (BP)-type UV filters are widely used in a variety of personal care products for the protection of skin and hair from UV irradiation. Despite the estrogenic potencies of BP derivatives, few studies have examined the occurrence of these compounds in human matrices. Furthermore, associations among exposure to these compounds and estrogen-dependent diseases (such as endometriosis) have not been examined previously. In this study, we determined the concentrations of five BP derivatives, 2-hydroxy-4-methoxybenzophenone (2OH-4MeO-BP), 2,4-dihydroxybenzophenone (2,4OH-BP), 2,2'-dihydroxy-4-methoxybenzophenone (2,2'OH-4MeO-BP), 2,2',4,4'-tetrahydroxybenzophenone (2,2',4,4'OH-BP), and 4-hydroxybenzophenone (4OH-BP), in urine collected from 625 women in Utah and California, using liquid chromatography (LC)-tandem mass spectrometry (MS/MS). The association of urinary concentrations of BP derivatives with an increase in the odds of a diagnosis of endometriosis was examined in 600 women who underwent laparoscopy/laparotomy (n = 473: operative cohort) or pelvic magnetic resonance imaging (n = 127: population cohort), during 2007-2009. 2OH-4MeO-BP, 2,4OH-BP, and 4OH-BP respectively were detected in 99.0%, 93.3%, and 83.8% of the urine samples analyzed, whereas the detection rates for 2,2',4,4'OH-BP and 2,2'OH-4MeO-BP were below 6.0%. Significant regional differences (higher concentrations in California) and monthly variations (higher concentrations in July and August) were found for urinary concentrations of 2OH-4MeO-BP and 2,4OH-BP. In addition, urinary concentrations of 2OH-4MeO-BP and 2,4OH-BP tended to be higher in more affluent, older, and leaner women. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for the urinary concentrations of BP derivatives and the odds of an endometriosis diagnosis; ORs increased across quartiles of 2OH-4MeO-BP and 2,4OH-BP concentrations, but a significant trend was observed only between 2,4OH-BP and the odds of an endometriosis diagnosis in the operative cohort (OR = 1.19; 95% CI = 1.01, 1.41). When women in the highest quartile of 2,4OH-BP concentrations were compared with women in the first three quartiles, the OR increased considerably (OR = 1.65; 95% CI = 1.07, 2.53). Given that 2,4OH-BP possesses an estrogenic activity higher than that of 2OH-4MeO-BP, our results invite the speculation that exposure to elevated 2,4OH-BP levels may be associated with endometriosis.

Cytochromes P450: Roles in the Biotransformation of Chemicals in Cigarette Smoke and Impact of Smoking Cessation on Concurrent Drug Therapy

Cigarette smoke contains polycyclic aromatic hydrocarbons (PAHs) that activate the expression of cytochrome P450 family 1 (CYP1) enzymes in liver and other tissues; this process is dependent on the aryl hydrocarbon receptor (AhR) transcription factor. An important CYP1 enzyme, CYP1A2, has a critical role in the oxidation of drugs such as clozapine, olanzapine and theophylline; these drugs exhibit a high incidence of adverse effects that are linked to plasma concentrations. This article reviews the impact of smoking and smoking cessation on therapy with toxic drugs that undergo CYP-mediated elimination. PAHs in cigarette smoke activate the AhR and upregulate CYP1A2, which enhances the clearance of these drugs, diminishes their efficacy and necessitates the use of higher doses. However, smoking cessation decreases PAH exposure, which leads to a decline in clearance of CYP1A2 substrate drugs. Dose reductions and close therapeutic monitoring for such drugs are recommended in patients who cease smoking.

Cigarette smoking and its relationship to mood disorder symptoms and co-occurring alcohol and cannabis use disorders following first hospitalization for bipolar disorder

OBJECTIVES

Cigarette smoking is highly prevalent among individuals with bipolar disorder (BD) and may adversely affect symptoms of the disorder, as well as the co-occurrence of other substance use disorders. However, anecdotal reports suggesting that smoking cessation caused a worsening of mood in smokers with BD have raised concerns about quitting. In the present study, we prospectively evaluated the course of BD, alcohol use disorders, and cannabis use disorders in relation to smoking and examined the relationship between smoking abstinence and changes in mood.

METHODS

Participants (N = 161) were adolescents (n=80) and adults (n = 81) with bipolar I disorder who were hospitalized for their initial mixed or manic episode. Participants were followed up to eight years post-hospitalization (median follow-up = 122 weeks) as part of a naturalistic, observational study of the longitudinal course of BD and substance use.

RESULTS

The course of BD symptoms in the 12 months following index hospitalization did not differ by smoking status in either the adolescent or the adult subsample. Among adolescents, smoking was associated with an increased risk of having a cannabis or alcohol use disorder, almost all of which were new-onset disorders, in the year following first hospitalization. Neither adolescents nor adults who were abstinent from smoking for at least two months experienced significant increases in depressive or manic symptoms.

CONCLUSIONS

Although cigarette smoking did not predict a worse course of BD, smoking was associated with an increased risk of developing alcohol and cannabis use disorders in adolescents with BD. Importantly, these data provide no evidence to suggest that abstinence from smoking is associated with worsening symptoms of depression or mania in the short term.