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Objective To assess dependence levels in users of e-cigarettes, and compare them with dependence levels in users of nicotine gums and tobacco cigarettes. Design Self-reports from cross-sectional Internet and mail surveys. Comparisons of: (a) 766 daily users of nicotine-containing e-cigarettes with 30 daily users of nicotine-free e-cigarettes; (b) 911 former smokers who used the e-cigarette daily with 451 former smokers who used the nicotine gum daily (but no e-cigarette); (c) 125 daily e-cigarette users who smoked daily (dual users) with two samples of daily smokers who did not use e-cigarettes (2206 enrolled on the Internet and 292 enrolled by mail from the general population of Geneva). We used the Fagerström test for nicotine dependence, the nicotine dependence syndrome scale, the cigarette dependence scale and versions of these scales adapted for e-cigarettes and nicotine gums. Results Dependence ratings were slightly higher in users of nicotine-containing e-cigarettes than in users of nicotine-free e-cigarettes. In former smokers, long-term (>3 months) users of e-cigarettes were less dependent on e-cigarettes than long-term users of the nicotine gum were dependent on the gum. There were few differences in dependence ratings between short-term (≤3 months) users of gums or e-cigarettes. Dependence on e-cigarettes was generally lower in dual users than dependence on tobacco cigarettes in the two other samples of daily smokers. Conclusions Some e-cigarette users were dependent on nicotine-containing e-cigarettes, but these products were less addictive than tobacco cigarettes. E-cigarettes may be as or less addictive than nicotine gums, which themselves are not very addictive. [ABSTRACT FROM AUTHOR]

This paper will review clinical pharmacology studies on buprenorphine, a mixed opioid agonist–antagonist currently approved as a treatment for opioid dependence. The focus is on studies characterizing buprenorphine''s pharmacodynamic actions, including its safety, abuse liability, withdrawal suppression and withdrawal precipitation capacity, physical dependence potential, cross-tolerance and duration of action as well as a review of the pharmacological profile of buprenorphine/naloxone combinations. The findings from these clinical pharmacology studies are synthesized and presented in a framework designed to (1) inform clinicians about the advantages and disadvantages of buprenorphine as an opioid maintenance agent, and (2) provide information about dosing procedures that may optimize the use of buprenorphine in the clinic. [Copyright &y& Elsevier]

Background: Recent regulations have banned all flavors except menthol/mint and classic tobacco from pod-based e-cigarette devices such as JUUL. However, menthol/mint flavor can present a potential risk given its increasing popularity among young people in the US and its puffing and nicotine-enhancing properties. This study examines the impact of menthol/mint flavor manipulation on users' puffing behavior, subjective experience, and nicotine exposure among young people.Methods: JUUL users (n = 33, 18-24 years) attended two 60-min ad libitum e-cigarette use sessions (menthol/mint flavor vs. classic tobacco flavor) in a cross-over design. Puff topography and plasma nicotine concentration were measured, and participants completed subjective experience questionnaires.Results: Following the use of the menthol/mint-flavored pod, increases were observed in measures of satisfaction, pleasurable/interest to use, willingness to use again, enjoyment, urge to vape, product appeal, taste, and concentration (p < .05 for all). For example, compared to the classic tobacco flavor, participants experienced significantly more satisfaction of the product (4.24 vs. 3.09; p = .001) and sensation enjoyment of the product (3.55 vs. 2.48; p = .002) when using the menthol/mint flavor. While means of the plasma nicotine boost and puff parameters were lower in the classic tobacco condition compared to the menthol/mint flavor condition, no statistical significance was observed between the two conditions (p > .05 for all).Conclusions: Results of this pilot study suggest that menthol/mint-flavor increases e-cigarette users' subjective experience significantly. Regulating menthol/mint flavor is a potentially promising strategy to curb e-cigarette use among young people. [ABSTRACT FROM AUTHOR]

Nicotine form (freebase/protonated) and nicotine flux (rate at which nicotine is emitted) are two factors that can affect the dose of nicotine inhaled by individuals using electronic nicotine delivery systems (ENDS) because they can influence puffing behavior. The nicotine dose for each puff also is directly proportional to nicotine flux (i.e., dose/puff=nicotine flux*puff duration). This study examines the effect of nicotine form and flux on puffing parameters and mouth-level nicotine exposure. Thirty-two dual ENDS and combustible cigarette participants completed five visits that differed by nicotine form (freebase or protonated) and nicotine flux (14 or 35 µg/sec); a zero-nicotine condition was a negative control. Participants used a Subox Mini C ENDS, powered at 20 W, during a 10-puff directed bout (B1) followed by a one-hour ad libitum bout (B2). Puffing parameters and mouth-level nicotine exposure were assessed using the American University of Beirut REALTIME instrument. Relative to protonated nicotine, freebase nicotine was associated with lower total puff duration (puff duration*number of puffs), lower flow rate in B1, lower liquid consumption, and lower mouth-level nicotine exposure. Increasing nicotine flux from 14 to 35 µg/sec was associated with lower total puff duration in both bouts, as well as lower liquid consumption. Increasing nicotine flux was associated with higher mouth-level nicotine exposure in B1 only. ENDS with protonated nicotine may enhance nicotine exposure by promoting longer puffing and thus greater dose delivered. This work highlights the importance of accounting for interactions between nicotine form and flux when considering nicotine regulation for ENDS. • ENDS with protonated nicotine elicit longer puffs compared to freebase nicotine. • ENDS with protonated nicotine result in greater mouth-level exposure to nicotine. • Greater nicotine flux result in fewer and shorter puffs. • Greater nicotine flux result in greater mouth-level nicotine exposure.. [ABSTRACT FROM AUTHOR]

• Nicotine/drug-related subjective effects driven by ECIG nicotine content. • Acceptability results not related consistently to ECIG nicotine/flavor content. • Little evidence that ECIG flavors masked/enhanced subjective effects. A rapidly evolving tobacco marketplace highlights the timeliness of the FDA's authority to regulate tobacco, specifically the role that flavorings in nicotine-containing electronic cigarette (ECIG) liquids have on public health. This study aimed to evaluate the extent to which ECIG liquid flavor and nicotine concentration influenced subjective measures of abuse liability among young adult cigarette (cig) smokers. Young adult (18–21 y.o.) smokers (M = 10.1 cig/day, no regular ECIG use history) completed 7 Latin-square ordered conditions each preceded by 12 h. nicotine/tobacco abstinence. Conditions were own brand cig (OB) and eGo-style ECIG paired with three liquid flavors (cream, tropical fruit, tobacco/menthol) varying in nicotine concentration (0 or 36 mg/ml). Products were administered in two 10-puff bouts in each condition. Heart rate/blood pressure (HR/BP) and tobacco/nicotine abstinence symptoms, nicotine/general drug effects, and acceptability measures were assessed repeatedly throughout sessions. Mixed linear models were followed-up with Tukey's HSD t -tests. HR/BP indicated nicotine exposure during nicotine-containing conditions. OB and tobacco/menthol 36 mg/ml conditions produced significant decreases in ratings of cig smoking urges. Nicotine/drug effects were elevated significantly for OB and 36 mg/ml ECIG conditions with one exception noted for the tobacco/menthol 0 mg/ml condition. OB had the highest acceptability ratings, and ECIG condition results varied by acceptability item. Among young adult smokers, ECIG conditions containing nicotine were positively associated with several subjective measures of abuse liability but not all. Flavors did not consistently mask/enhance effects observed. Results reinforce continued examination of ECIG-delivered nicotine and liquid flavors in relationship to abuse liability. [ABSTRACT FROM AUTHOR]

Background: A rapidly evolving tobacco marketplace highlights the timeliness of the FDA's authority to regulate tobacco, specifically the role that flavorings in nicotine-containing electronic cigarette (ECIG) liquids have on public health. This study aimed to evaluate the extent to which ECIG liquid flavor and nicotine concentration influenced subjective measures of abuse liability among young adult cigarette (cig) smokers.Methods: Young adult (18-21 y.o.) smokers (M = 10.1 cig/day, no regular ECIG use history) completed 7 Latin-square ordered conditions each preceded by 12 h. nicotine/tobacco abstinence. Conditions were own brand cig (OB) and eGo-style ECIG paired with three liquid flavors (cream, tropical fruit, tobacco/menthol) varying in nicotine concentration (0 or 36 mg/ml). Products were administered in two 10-puff bouts in each condition. Heart rate/blood pressure (HR/BP) and tobacco/nicotine abstinence symptoms, nicotine/general drug effects, and acceptability measures were assessed repeatedly throughout sessions. Mixed linear models were followed-up with Tukey's HSD t-tests.Results: HR/BP indicated nicotine exposure during nicotine-containing conditions. OB and tobacco/menthol 36 mg/ml conditions produced significant decreases in ratings of cig smoking urges. Nicotine/drug effects were elevated significantly for OB and 36 mg/ml ECIG conditions with one exception noted for the tobacco/menthol 0 mg/ml condition. OB had the highest acceptability ratings, and ECIG condition results varied by acceptability item.Conclusions: Among young adult smokers, ECIG conditions containing nicotine were positively associated with several subjective measures of abuse liability but not all. Flavors did not consistently mask/enhance effects observed. Results reinforce continued examination of ECIG-delivered nicotine and liquid flavors in relationship to abuse liability. [ABSTRACT FROM AUTHOR]

Background Electronic cigarettes (ECIGs) are a class of tobacco products that produce different effects (e.g., nicotine delivery), depending on the device, liquid, and behavioral factors. However, the influence of the two primary ECIG liquid solvents, propylene glycol (PG) and vegetable glycerin (VG), on ECIG acute effects is unknown. Methods Thirty ECIG-experienced, ≥12-h nicotine- abstinent participants completed four conditions consisting of two ECIG-use bouts (10 puffs, 30 s interpuff-interval) differing only by liquid PG:VG ratio (2PG:98VG, 20PG:80VG, 55PG:45VG, 100PG). Device power (7.3 W) and liquid nicotine concentration (18 mg/ml) remained constant. Nicotine delivery, subjective effects, heart rate (HR), and puff topography were assessed. Results In the 100PG condition, participants took shorter and smaller puffs but obtained significantly more nicotine relative to the two VG-based conditions. Total nicotine exposure (i.e., area under the curve) was also significantly higher during use of the two PG-based liquids. However, participants reported that the 100 PG liquid was significantly less “pleasant” and “satisfying” relative to the other liquids (all p s < .05). Increases in HR and decreases in abstinence symptoms (e.g., “craving”) did not differ across conditions. Conclusions PG:VG ratio influenced nicotine delivery, some subjective effects, and puff topography. Lower overall product satisfaction associated with the 100PG liquid suggests factors other than nicotine delivery (e.g., aerosol visibility) may play a role in maintaining ECIG use. Regulating ECIG acute effects such as nicotine delivery and subjective effects may require simultaneous attention to liquid PG:VG ratio as well as device, liquid, and behavioral factors known to influence these outcomes. [ABSTRACT FROM AUTHOR]

Background: Electronic cigarettes (ECIGs) are a class of tobacco products that produce different effects (e.g., nicotine delivery), depending on the device, liquid, and behavioral factors. However, the influence of the two primary ECIG liquid solvents, propylene glycol (PG) and vegetable glycerin (VG), on ECIG acute effects is unknown.Methods: Thirty ECIG-experienced, ≥12-h nicotine- abstinent participants completed four conditions consisting of two ECIG-use bouts (10 puffs, 30 s interpuff-interval) differing only by liquid PG:VG ratio (2PG:98VG, 20PG:80VG, 55PG:45VG, 100PG). Device power (7.3 W) and liquid nicotine concentration (18 mg/ml) remained constant. Nicotine delivery, subjective effects, heart rate (HR), and puff topography were assessed.Results: In the 100PG condition, participants took shorter and smaller puffs but obtained significantly more nicotine relative to the two VG-based conditions. Total nicotine exposure (i.e., area under the curve) was also significantly higher during use of the two PG-based liquids. However, participants reported that the 100 PG liquid was significantly less "pleasant" and "satisfying" relative to the other liquids (all ps < .05). Increases in HR and decreases in abstinence symptoms (e.g., "craving") did not differ across conditions.Conclusions: PG:VG ratio influenced nicotine delivery, some subjective effects, and puff topography. Lower overall product satisfaction associated with the 100PG liquid suggests factors other than nicotine delivery (e.g., aerosol visibility) may play a role in maintaining ECIG use. Regulating ECIG acute effects such as nicotine delivery and subjective effects may require simultaneous attention to liquid PG:VG ratio as well as device, liquid, and behavioral factors known to influence these outcomes. [ABSTRACT FROM AUTHOR]

Background: Electronic cigarettes (ECIGs) aerosolize liquids for user inhalation that usually contain nicotine. ECIG nicotine emission is determined, in part, by user behavior, liquid nicotine concentration, and electrical power. Whether users are able to report accurately nicotine concentration and device electrical power has not been evaluated. This study's purpose was to examine if ECIG users could provide data relevant to understanding ECIG nicotine emission, particularly liquid nicotine concentration (mg/ml) as well as battery voltage (V) and heater resistance (ohms, Ω) - needed to calculate power (watts, W).Methods: Adult ECIG users (N=165) were recruited from Los Angeles, CA for research studies examining the effects of ECIG use. We asked all participants who visited the laboratory to report liquid nicotine concentration, V, and Ω.Results: Liquid nicotine concentration was reported by 89.7% (mean=9.5mg/ml, SD=7.3), and responses were consistent with the distribution of liquids available in commonly marketed products. The majority could not report voltage (51.5%) or resistance (63.6%). Of the 40 participants (24.8%) who reported voltage and resistance, there was a substantial power range (2.2-32,670W) the upper limit of which exceeds that of the highest ECIG reported by any user to our knowledge (i.e., 2512W). If 2512W is taken as the upper limit, only 30 (18.2%) reported valid results (mean 237.3W, SD=370.6; range=2.2-1705.3W).Conclusions: Laboratory, survey, and other researchers interested in understanding ECIG effects to inform users and policymakers may need to use methods other than user self-report to obtain information regarding device power. [ABSTRACT FROM AUTHOR]

Background: Novel tobacco products entering the US market include electronic cigarettes (ECIGs) and products advertised to "heat, not burn" tobacco. There is a growing literature regarding the acute effects of ECIGs. Less is known about "heat, not burn" products. This study's purpose was to expand existing clinical laboratory methods to examine, in cigarette smokers, the acute effects of a "heat, not burn" "loose-leaf tobacco vaporizer" (LLTV).Methods: Plasma nicotine and breath carbon monoxide (CO) concentration and tobacco abstinence symptom severity were measured before and after two 10-puff (30-s interpuff interval) product use bouts separated by 60min. LLTV effects were compared to participants' own brand (OB) cigarettes and an ECIG (3.3V; 1.5ohm; 18mg/ml nicotine).Results: Relative to OB, LLTV increased plasma nicotine concentration to a lesser degree, did not increase CO, and did not appear to reduce abstinence symptoms as effectively. Relative to ECIG, LLTV nicotine and CO delivery and abstinence symptom suppression did not differ. Participants reported that both the LLTV and ECIG were significantly less satisfying than OB.Conclusions: Results demonstrate that LLTVs are capable of delivering nicotine and suppressing tobacco abstinence symptoms partially; acute effects of these products can be evaluated using existing clinical laboratory methods. Results can inform tobacco product regulation and may be predictive of the extent that these products have the potential to benefit or harm overall public health. [ABSTRACT FROM AUTHOR]

Introduction: Waterpipe smoking is addictive and its use is increasing globally among youth, yet little is known about the factors associated with nicotine dependence (ND) among waterpipe smokers. We investigated the factors associated with ND symptoms among a sample of Lebanese adolescents who smoke a waterpipe.Methods: We collected data on factors potentially associated with ND (individual, socio-demographic, environmental, smoking patterns) among 160 current (past 30days) waterpipe smokers recruited from 8th and 9th school grades in Lebanon. We assessed the loss of autonomy over tobacco using the Hooked on Nicotine Checklist (HONC), ND using the International Classification of Diseases, 10th revision (ICD-10), and the number of ND symptoms endorsed.Results: Depressive symptoms, lower self-esteem, and having at least one sibling who smokes a waterpipe were associated with the presence of ND symptoms, while enrollment in public schools, smoking a waterpipe ≥30min per session, and believing that cigarette smoking is harmful to health were associated with endorsement of a higher number of ND symptoms. Smoking a whole waterpipe head without sharing and being in 9th grade in this study were associated with the presence and endorsement of a higher number of ND symptoms.Conclusions: We identified specific social and psychological characteristics, waterpipe smoking patterns, and beliefs about harmful effects of smoking associated with the presence of ND among adolescent waterpipe smokers. Considering these factors when planning policies to prevent ND among waterpipe smokers is warranted. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Alternative tobacco use among adolescents who smoke cigarettes is a growing public health concern, and evidence suggests that patterns of alternative tobacco use varies with respect to cigarette consumption and frequency of cigarette use. This study aimed to examine (a) whether variations in adolescent cigarette smoking and alternative tobacco use can be explained by underlying subtypes and (b) if these subtypes differ in their demographic and psychosocial characteristics. Methods: Using data from the 2009 National Youth Tobacco Survey, latent class analysis (LCA) was used to identify patterns of cigarette smoking and alternative tobacco use among 2746 current (past 30-day) smokers. After identification, classes were analyzed using multinomial logistic regression to examine differences based on demographics and smoking-related characteristics. Results: Four of the six latent classes identified (non-daily light smokers, chippers, chippers-Indulgent, intermittent smokers) reflected consumption, frequency, and history of cigarette use characteristics commonly attributed to light and intermittent smokers, and the remaining two classes (daily smokers, daily smokers-Indulgent) presented cigarette use behaviors commonly attributed to daily smokers. There were clear class differences in levels of alternative tobacco product use, demographics, and psychosocial characteristics. Conclusions: Study findings are consistent with previous work demonstrating demographic and psychosocial differences between cigarette smokers based on their alternative tobacco use. The six latent classes identified highlight the importance of including measures of alternative tobacco use when characterizing adolescent cigarette smokers as well as recognizing and tailoring interventions toward these different groups of tobacco users. [Copyright &y& Elsevier]

Abstract: Background: Waterpipe tobacco smoking usually involves heating flavored tobacco with charcoal and inhaling the resulting smoke after it has passed through water. Waterpipe tobacco smoking increases heart rate and produces subjective effects similar to those reported by cigarette smokers. These responses are thought to be nicotine-mediated, though no placebo-control studies exist. Accordingly, this double-blind, placebo-control study compared the acute physiological and subjective effects of waterpipe tobacco smoking to those produced when participants used a waterpipe to smoke a flavor-matched, tobacco-free preparation. Methods: Occasional waterpipe tobacco smokers (n =37; 2–5 monthly smoking episodes for ≥6 months) completed two double-blind, counterbalanced sessions that differed by product: preferred brand/flavor of waterpipe tobacco or flavor-matched, tobacco-free preparation. For each 45-min, ad lib smoking episode blood and expired air CO were sampled, cardiovascular and respiratory response were measured, and subjective response was assessed. Results: Waterpipe tobacco smoking significantly increased mean (±SEM) plasma nicotine concentration (3.6±0.7ng/ml) and heart rate (8.6±1.4bpm) while placebo did not (0.1±0.0ng/ml; 1.3±0.9bpm). For carboxyhemoglobin (COHb) and expired air CO, significant increases were observed for tobacco (3.8±0.4%; 27.9±2.6ppm) and for placebo (3.9±0.4%; 27.7±3.3ppm) with no differences across condition. Independent of condition, symptoms of nicotine/tobacco abstinence (e.g., “urges to smoke”, “anxious”) were reduced and direct effects (e.g., “dizzy”, “satisfy”) increased. Discussion: These results from the first placebo-control study of waterpipe tobacco smoking demonstrate that waterpipe-induced heart rate increases are almost certainly mediated by nicotine though the subjective effects observed in these occasional smokers were not. [Copyright &y& Elsevier]

Corrigendum to "Influence of electronic cigarette liquid flavors and nicotine concentration on subjective measures of abuse liability in young adult cigarette smokers" [Drug Alcohol Depend. [Extracted from the article]

Introduction: Little is known about differences in tobacco product dependence among people who use two tobacco products versus one. Self-reported product dependence among individuals using cigarettes only, electronic nicotine delivery systems (ENDS) only, and both cigarettes and ENDS (dual users) was compared.Method: PATH Wave 3 data were collected between 2015 and 2016. We used 11 Wisconsin Inventory of Smoking Dependence Motives items to assess cigarette and ENDS dependence, averaged to generate Cigarette Dependence (CD) and ENDS Dependence (ED) scores. Linear regression models were used to assess the association between tobacco use groups and the two dependence scores.Results: Our analytic sample included 5538 (91.5 %) cigarette only, 399 (6.7 %) ENDS only, and 108 (1.8 %) dual users. There was no difference in CD between cigarette only and dual users. ENDS only users' ED (2.11, SE = 0.05) was higher than dual users' ED (1.67, SE = 0.04) (p < 0.05). Dual users' mean ED (1.70, SE = 0.09) was significantly lower than their CD (3.03, SE = 0.11) (p < 0.001), and ENDS only users' ED (2.34, SE = 0.05) was significantly lower than cigarette only users' CD (2.94, SE = 0.02) (p < 0.001).Conclusion: While there was no difference in CD between dual and cigarette only users, dual users' ED was lower than that for ENDS only users. ENDS appeared to produce less dependence than cigarettes among dual users. Given the high nicotine concentration ENDS products that entered the market after PATH Wave 3 data were collected, future research should examine ED among ENDS only and dual users. [ABSTRACT FROM AUTHOR]

Objective: Identifying the factors associated with nicotine dependence (ND) is essential to prevent initiation and continued use, and to promote cessation among youth. This study aims to document the predictors of the appearance of initial ND symptoms and full ND syndrome among adolescent waterpipe (WP) and cigarette smokers.Methods: A 6-year longitudinal study was conducted among 8th and 9th graders from 38 schools in Lebanon. The analysis sample included exclusive-WP (n = 228) and exclusive-cigarette smokers (n = 139). Weighted Cox proportional hazards models were used to characterizing predictors of initial ND symptoms and full ND syndrome.Results: Predictors of experiencing initial ND symptoms among WP smokers included low maternal educational level, having a sibling who smoked WP, low physical activity, high body mass index (BMI), smoking initiation at a younger age. For cigarette smokers these were being male, younger, having lower BMI, having a sibling who smoked cigarettes, living in a crowded household, and smoking daily. Among WP smokers, predictors of developing full ND syndrome include being younger, believing that WP smokers have more friends, depression, high levels of impulsivity, and initiating smoking at a younger age. For cigarette smokers, predictors of full ND syndrome were being younger and initiating smoking at a younger age.Conclusion: Smoking cessation and prevention interventions targeting youth should address modifiable, and tobacco use-specific factors that influence the development of ND among young WP and cigarette smokers. They also need to start at a younger age to target those most vulnerable to developing life-long addiction to tobacco products. [ABSTRACT FROM AUTHOR]

Background: Waterpipe tobacco smoking (WTS) has surged globally among young people and causes nicotine dependence (ND). No existing ND instruments are sensitive to waterpipe-specific features of ND and early stages of use.Methods: We conducted a psychometric scale evaluation among 192 current waterpipe smokers, initially averaging 15 years of age, recruited from schools in Beirut, Lebanon, and assessed 4 times, 6 months apart. Twenty eight self-report items tapping multiple features of ND were submitted to exploratory and confirmatory factor analyses (EFA and CFA) to reduce items and verify factor structure. Convergent validity was assessed with the Lebanese Waterpipe Dependence Scale and the Hooked on Nicotine Checklist, and discriminant validity with the Depressive Symptom Scale and Adolescent Life Events Stress Scale. Concurrent and predictive validity measures included smoking status and intensity (amount, frequency, session duration, and change in frequency), quitting interest and success, perceived addiction, and smoking alone.Results: The EFA yielded a single factor, 13 item solution (named the Syrian Center for Tobacco Studies [SCTS]-13) that explained 91% of variance in responses, was internally consistent (Cronbach's alpha and McDonald's omega = 0.87), and captured several positive reinforcement, negative reinforcement, and social/sensory-related features of ND. The CFA indicated good model fit. The SCTS-13 showed acceptable convergent and discriminant validity. Higher SCTS-13 scores predicted current waterpipe and dual (waterpipe and cigarette) smoking, greater intensity of use, less interest in quitting, shorter duration of abstinence, greater perceived addiction, and smoking alone (vs. socially).Conclusion: The SCTS-13 is a promising brief, waterpipe-specific ND instrument. [ABSTRACT FROM AUTHOR]

Background: Waterpipe smoking is spreading worldwide, and it is associated with many adverse effects. The aim of this study was to investigate the interaction of waterpipe smoking puffing topography, and related physiological measures, with both gender and level of dependence on waterpipe.Method: Exclusive waterpipe smokers were asked to smoke a single waterpipe session in a specialized laboratory while their smoking topography, and in-breath CO level were recorded pre- and post- smoking. Waterpipe dependence was measured using the LWDS-11 scale.Results: In the high dependence group, the total number of puffs, was greater in men than women. In addition, the average flow rate was greater in men with high compared to low dependence. For inter-puffing intervals, greater values were recorded in men and women with low versus high dependence. No other differences were found between the subgroups in total session time, average puff duration, average puff volume, and maximum flow rate. Pre-smoking CO content and CO boost were greater in men versus women in both dependence groups. Post-smoking CO content was greater in women with high versus low dependence, whereas it was lower in women versus men with low dependence.Conclusions: The current results indicate several effects for waterpipe smoking dependence on smoking topography. Many of these differences were gender dependent with men having higher exposure than women in most aspects. [ABSTRACT FROM AUTHOR]

Introduction: Some HIV-positive smokers report ambivalence about quitting. Switching to electronic cigarettes (ECs) may be a viable option to reduce the negative health effects for smokers who are unable or unwilling to quit smoking combustible cigarettes (CCs). This study examined the acceptability and health-related effects of ECs in HIV-positive smokers who were not seeking smoking cessation treatment.Methods: HIV-positive smokers (N = 19) were enrolled and followed for 12 weeks. Cartridge-based ECs were provided at baseline, and E-liquid was provided weekly for 8 weeks. At baseline, weeks 1-8, and week 12, EC and CC use, cardiopulmonary function, respiratory symptoms, and carbon monoxide (CO) levels were measured.Results: At week 8, cigarettes per day (CPD) were reduced by more than 80%, with reduction maintained at week 12 (p's < .001). Cigarette dependence scores were 40% lower at week 8 than at baseline (p <  .001). Seven (36.8%) participants reported transitioning completely from CCs to ECs. Mean CO decreased significantly from BL to week 8 (p < .05) and remained significantly lower at week 12 (p <  .001). Intention to quit increased significantly over time.Conclusions: Switching from CCs to ECs in HIV-positive smokers who are not ready to quit smoking in the next 30 days appears to be feasible. Beneficial effects were seen, such as reduced CPD, reduced CO and CC dependence, and increased motivation to quit. ECs may be promising as a harm reduction approach among HIV-positive smokers who are unable or unwilling to quit smoking. [ABSTRACT FROM AUTHOR]

This paper will review clinical pharmacology studies on buprenorphine, a mixed opioid agonist-antagonist currently approved as a treatment for opioid dependence. The focus is on studies characterizing buprenorphine's pharmacodynamic actions, including its safety, abuse liability, withdrawal suppression and withdrawal precipitation capacity, physical dependence potential, cross-tolerance and duration of action as well as a review of the pharmacological profile of buprenorphine/naloxone combinations. The findings from these clinical pharmacology studies are synthesized and presented in a framework designed to (1) inform clinicians about the advantages and disadvantages of buprenorphine as an opioid maintenance agent, and (2) provide information about dosing procedures that may optimize the use of buprenorphine in the clinic. [ABSTRACT FROM AUTHOR]