1
|
Campbell C, Jin T, Round EK, Schmidt E, Nelson P, Baxter S. Part one: abuse liability of Vuse Solo (G2) electronic nicotine delivery system relative to combustible cigarettes and nicotine gum. Sci Rep 2022; 12:22080. [PMID: 36543869 PMCID: PMC9772348 DOI: 10.1038/s41598-022-26417-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
Abuse liability (AL) of electronic nicotine delivery systems (ENDS) is relevant as the category increases in popularity as a potentially less-harmful alternative to cigarette smoking. AL assessments are important to the FDA in determining if a new product is appropriate for the protection of public health. This paper reports the results for Vuse Solo (G2 cartridge design) compared to high and low AL-comparators evaluated in an open-label, randomized crossover confinement AL study. The confinement design was adapted from previous ambulatory studies of Vuse Solo (G1 cartridge design) and included product familiarization sessions before each four-hour test session in which subjective measures, nicotine pharmacokinetics (PK), and physiological endpoints were assessed following a single 10-min ad libitum product use session. Product liking, intent to use again, suppression of urge to smoke, and nicotine PK were lower after use of Vuse Solo compared to cigarettes and higher after use of Vuse Solo compared to nicotine gum. No significant differences in blood pressure or heart rate were observed between the products pre- to post-product use. These data reinforce previous research and provide the scientific evidence to support regulatory decisions demonstrating that Vuse Solo has an AL profile lower than that of combustible cigarettes but higher than that of nicotine gum and, therefore, may be a suitable replacement for cigarette smoking for some adult smokers.
Collapse
Affiliation(s)
- Chris Campbell
- RAI Services Company, 401 N. Main Street, Winston-Salem, NC, 27101, USA.
| | - Tao Jin
- RAI Services Company, 401 N. Main Street, Winston-Salem, NC, 27101, USA
| | - Elaine K Round
- RAI Services Company, 401 N. Main Street, Winston-Salem, NC, 27101, USA
| | - Eckhardt Schmidt
- RAI Services Company, 401 N. Main Street, Winston-Salem, NC, 27101, USA
| | - Paul Nelson
- Retired Employee of RAI Services Company, Winston-Salem, NC, 27101, USA
| | - Sarah Baxter
- RAI Services Company, 401 N. Main Street, Winston-Salem, NC, 27101, USA
| |
Collapse
|
2
|
Smith LC, George O. Advances in smoking cessation pharmacotherapy: Non-nicotinic approaches in animal models. Neuropharmacology 2020; 178:108225. [PMID: 32758566 DOI: 10.1016/j.neuropharm.2020.108225] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 06/26/2020] [Accepted: 06/28/2020] [Indexed: 12/22/2022]
Abstract
The landscape of worldwide tobacco use is changing, with a decrease in traditional smoking and an exponential rise in electronic cigarette use. No new nicotine cessation pharmacotherapies have come to market in the last 10 years. The current therapies that have been approved by the United States Food and Drug Administration for nicotine cessation include nicotine replacement therapy, varenicline, a nicotinic acetylcholine receptor partial agonist, and the atypical antidepressant bupropion. Nicotine replacement therapy and varenicline both act on nicotinic acetylcholine receptors. Bupropion inhibits the dopamine transporter, the norepinephrine transporter, and the nicotinic acetylcholine receptors to inhibit smoking behavior. Notwithstanding these treatments, rates of successful nicotine cessation in clinical trials remain low. Recent pharmacological approaches to improve nicotine cessation rates in animal models have turned their focus away from activating nicotinic acetylcholine receptors. The present review focuses on such pharmacological approaches, including nicotine vaccines, anti-nicotine antibodies, nicotine-degrading enzymes, cannabinoids, and metformin. Both immunopharmacological and enzymatic approaches rely on restricting and degrading nicotine within the periphery, thus preventing psychoactive effects of nicotine on the central nervous system. In contrast, pharmacologic inhibition of the enzymes which degrade nicotine could affect smoking behavior. Cannabinoid receptor agonists and antagonists interact with the dopamine reward pathway and show efficacy in reducing nicotine addiction-like behaviors in preclinical studies. Metformin is currently approved by the Food and Drug Administration for the treatment of diabetes. It activates specific intracellular kinases that may protect against the lower metabolism, higher oxidation, and inflammation that are associated with nicotine withdrawal. Further studies are needed to investigate non-nicotinic targets to improve the treatment of tobacco use disorder. This article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology'.
Collapse
Affiliation(s)
- Lauren C Smith
- Department of Neuroscience, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA, 92037, USA; Department of Psychiatry, University of California, San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Olivier George
- Department of Neuroscience, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA, 92037, USA; Department of Psychiatry, University of California, San Diego, School of Medicine, La Jolla, CA, 92093, USA.
| |
Collapse
|
3
|
Lee H, Chung S, Noh J. Maternal Nicotine Exposure During Late Gestation and Lactation Increases Anxiety-Like and Impulsive Decision-Making Behavior in Adolescent Offspring of Rat. Toxicol Res 2016; 32:275-280. [PMID: 27818729 PMCID: PMC5080857 DOI: 10.5487/tr.2016.32.4.275] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/28/2016] [Accepted: 08/03/2016] [Indexed: 11/20/2022] Open
Abstract
Prenatal nicotine exposure over an entire pregnancy has been associated with an increased prevalence of hyperactivity, anxiety-like behavior and depression-like behavior in mature rats. However, the effects of maternal nicotine exposure in late gestation and lactation on the psychology and behavior of adolescent rat offspring are unclear. Thus, we investigated the effect of nicotine exposure during late gestation and lactation on anxiety-like and impulsive decision-making behavior in adolescent offspring of rat. Female rats were orally exposed to nicotine which is within range of plasma level of human chronic smokers during the period of third last period of gestation and lactation. When the offspring were weaned, we observed alterations in the anxiety-like behavior and decision-making ability of adolescent rat offspring using light/dark box test and T-maze delay-based cost-benefit decision-making task. The maternal consumption of nicotine reduced both the time spent in the light compartment and the number of transitions compared to nicotine-free rats. Moreover, such nicotine exposed adolescent offspring rats showed impulsive decision making which chose the instant reward in a decision-making situation. We found that nicotine exposure during late gestation and lactation induces an increase in anxiety-like and impulsive decision-making behavior at this developmental stage. These findings suggest that maternal nicotine-exposed offspring are at an increased risk of developing anxious and impulsive behavior.
Collapse
Affiliation(s)
- Hyunchan Lee
- Department of Science Education, College of Education, Dankook University, Gyeonggi, Korea
| | - Sooyeon Chung
- Department of Science Education, College of Education, Dankook University, Gyeonggi, Korea
| | - Jihyun Noh
- Department of Science Education, College of Education, Dankook University, Gyeonggi, Korea
| |
Collapse
|
4
|
Henderson BJ, Lester HA. Inside-out neuropharmacology of nicotinic drugs. Neuropharmacology 2015; 96:178-93. [PMID: 25660637 DOI: 10.1016/j.neuropharm.2015.01.022] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 01/20/2015] [Accepted: 01/20/2015] [Indexed: 02/05/2023]
Abstract
Upregulation of neuronal nicotinic acetylcholine receptors (AChRs) is a venerable result of chronic exposure to nicotine; but it is one of several consequences of pharmacological chaperoning by nicotine and by some other nicotinic ligands, especially agonists. Nicotinic ligands permeate through cell membranes, bind to immature AChR oligomers, elicit incompletely understood conformational reorganizations, increase the interaction between adjacent AChR subunits, and enhance the maturation process toward stable AChR pentamers. These changes and stabilizations in turn lead to increases in both anterograde and retrograde traffic within the early secretory pathway. In addition to the eventual upregulation of AChRs at the plasma membrane, other effects of pharmacological chaperoning include modifications to endoplasmic reticulum stress and to the unfolded protein response. Because these processes depend on pharmacological chaperoning within intracellular organelles, we group them as "inside-out pharmacology". This term contrasts with the better-known, acute, "outside-in" effects of activating and desensitizing plasma membrane AChRs. We review current knowledge concerning the mechanisms and consequences of inside-out pharmacology. This article is part of the Special Issue entitled 'The Nicotinic Acetylcholine Receptor: From Molecular Biology to Cognition'.
Collapse
Affiliation(s)
- Brandon J Henderson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Henry A Lester
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
| |
Collapse
|
5
|
Cohen A, George O. Animal models of nicotine exposure: relevance to second-hand smoking, electronic cigarette use, and compulsive smoking. Front Psychiatry 2013; 4:41. [PMID: 23761766 PMCID: PMC3671664 DOI: 10.3389/fpsyt.2013.00041] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/13/2013] [Indexed: 12/23/2022] Open
Abstract
Much evidence indicates that individuals use tobacco primarily to experience the psychopharmacological properties of nicotine and that a large proportion of smokers eventually become dependent on nicotine. In humans, nicotine acutely produces positive reinforcing effects, including mild euphoria, whereas a nicotine abstinence syndrome with both somatic and affective components is observed after chronic nicotine exposure. Animal models of nicotine self-administration and chronic exposure to nicotine have been critical in unveiling the neurobiological substrates that mediate the acute reinforcing effects of nicotine and emergence of a withdrawal syndrome during abstinence. However, important aspects of the transition from nicotine abuse to nicotine dependence, such as the emergence of increased motivation and compulsive nicotine intake following repeated exposure to the drug, have only recently begun to be modeled in animals. Thus, the neurobiological mechanisms that are involved in these important aspects of nicotine addiction remain largely unknown. In this review, we describe the different animal models available to date and discuss recent advances in animal models of nicotine exposure and nicotine dependence. This review demonstrates that novel animal models of nicotine vapor exposure and escalation of nicotine intake provide a unique opportunity to investigate the neurobiological effects of second-hand nicotine exposure, electronic cigarette use, and the mechanisms that underlie the transition from nicotine use to compulsive nicotine intake.
Collapse
Affiliation(s)
- Ami Cohen
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA
| | - Olivier George
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, USA
| |
Collapse
|
6
|
Fagerström K, Eissenberg T. Dependence on tobacco and nicotine products: a case for product-specific assessment. Nicotine Tob Res 2012; 14:1382-90. [PMID: 22459798 PMCID: PMC3611984 DOI: 10.1093/ntr/nts007] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Accepted: 01/09/2012] [Indexed: 01/03/2023]
Abstract
The International Classification of Diseases and the Diagnostic and Statistical Manual for diagnosing tobacco/nicotine dependence emphasize the dependence-producing drug nicotine. These diagnostic tools have been challenged on grounds of poor predictive validity, and they do not differentiate across various forms of nicotine-containing products. In fact, nicotine-containing products (e.g., tobacco cigarettes, smokeless tobacco [ST], waterpipe, electronic cigarettes [ECIGs], and nicotine replacement [NR] products) have very different characteristics both in terms of sensory and behavioral involvement and also in pharmacokinetic and pharmacodynamic effects. For example, a cigarette and a nicotine patch are very different on almost every one of these dimensions. When ability to stop using a nicotine/tobacco product is used as a criterion for dependence, success rates vary considerably across products: Tobacco cigarette cessation is more difficult than ST cessation that in turn is more difficult than NR product cessation. Based on these results, we hypothesize that there is a continuum of dependence as much as there is a continuum of harm, with tobacco cigarettes and NR products on opposite ends of both continua and other products (waterpipe and ECIGs) somewhere in between. In order to capture more precisely the dependence produced by both nicotine and its administration forms, product-specific instruments may be required. The pros and cons of this approach are discussed.
Collapse
Affiliation(s)
- Karl Fagerström
- Fagerstrom Consulting AB, Jordkulls Gård 3670, 26878 Kågeröd, Sweden.
| | | |
Collapse
|
7
|
Flanders-Stepans MB, Fuller SG. Physiological effects of infant exposure to environmental tobacco smoke: a passive observation study. J Perinat Educ 2012; 8:10-21. [PMID: 22945973 DOI: 10.1624/105812499x86944] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This study explored infant physiologic responses of exposure to environmental tobacco smoke (ETS) using a longitudinal passive observation study with a control group. Fifteen smoking and 15 non-smoking mothers were initially contacted in hospital maternity units, with home visits made when their infants were 2, 4, and 6 weeks old. Exposure to ETS was measured using infant urinary nicotine and cotinine levels. The physiologic effects of infant ETS exposure were measured by rectal temperature, pulse rate, respiratory rate, blood pressure, and oxygen saturation. The smoking mothers in this sample were poorer, had less education, and were less likely to be married than the mothers who did not smoke. At birth, the infants of smoking mothers had higher diastolic blood pressure than infants of non-smoking mothers (p < .008). Mothers who smoke cigarettes should be educated that maternal smoking behavior can affect an infant's cardiovascular function. Parents should also be counseled about the risks of smoking in close proximity and/or in an enclosed space with an infant, especially in a motor vehicle.
Collapse
Affiliation(s)
- M B Flanders-Stepans
- M ary B eth F landers -S tepans is an Assistant Professor in the School of Nursing at the University of Wyoming in Laramie, Wyoming
| | | |
Collapse
|
8
|
Passive immunization with a nicotine-specific monoclonal antibody decreases brain nicotine levels but does not precipitate withdrawal in nicotine-dependent rats. Pharmacol Biochem Behav 2009; 93:105-11. [PMID: 19393688 DOI: 10.1016/j.pbb.2009.04.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 04/13/2009] [Accepted: 04/18/2009] [Indexed: 11/24/2022]
Abstract
Vaccination against nicotine is under investigation as a treatment for tobacco dependence. Passive immunization with nicotine-specific antibodies represents a complementary strategy to vaccination. A potential adverse effect of passive immunization in nicotine-dependent individuals is that it may lead to a rapid reduction in brain nicotine levels and trigger withdrawal. The goal of this study was to determine if passive immunization with the nicotine-specific monoclonal antibody Nic311 precipitated withdrawal in nicotine-dependent rats as measured by increases in brain reward thresholds and somatic signs. Another cohort of rats was used to measure brain nicotine levels after Nic311 administration. Nic311 30, 80 or 240 mg/kg reduced brain nicotine concentrations by 45, 83 or 92% compared to controls. None of these Nic311 doses precipitated withdrawal measured at intervals up to 72 h following antibody administration. Administration of the nicotinic antagonist mecamylamine precipitated a robust nicotine withdrawal syndrome. Therefore, a substantial, but not complete, acute reduction in brain nicotine levels following passive immunization was not sufficient to precipitate nicotine withdrawal in nicotine-dependent rats. The Nic311 doses used have been shown to attenuate the behavioral effects of nicotine, suggesting that the use of passive immunization to treat nicotine addiction is not likely to precipitate withdrawal.
Collapse
|
9
|
Ochoa ELM, Lasalde-Dominicci J. Cognitive deficits in schizophrenia: focus on neuronal nicotinic acetylcholine receptors and smoking. Cell Mol Neurobiol 2008; 27:609-39. [PMID: 17554626 PMCID: PMC4676572 DOI: 10.1007/s10571-007-9149-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2006] [Accepted: 04/13/2007] [Indexed: 02/08/2023]
Abstract
Patients with schizophrenia present with deficits in specific areas of cognition. These are quantifiable by neuropsychological testing and can be clinically observable as negative signs. Concomitantly, they self-administer nicotine in the form of cigarette smoking. Nicotine dependence is more prevalent in this patient population when compared to other psychiatric conditions or to non-mentally ill people. The target for nicotine is the neuronal nicotinic acetylcholine receptor (nAChR). There is ample evidence that these receptors are involved in normal cognitive operations within the brain. This review describes neuronal nAChR structure and function, focusing on both cholinergic agonist-induced nAChR desensitization and nAChR up-regulation. The several mechanisms proposed for the nAChR up-regulation are examined in detail. Desensitization and up-regulation of nAChRs may be relevant to the physiopathology of schizophrenia. The participation of several subtypes of neuronal nAChRs in the cognitive processing of non-mentally ill persons and schizophrenic patients is reviewed. The role of smoking is then examined as a possible cognitive remediator in this psychiatric condition. Finally, pharmacological strategies focused on neuronal nAChRs are discussed as possible therapeutic avenues that may ameliorate the cognitive deficits of schizophrenia.
Collapse
Affiliation(s)
- Enrique L. M. Ochoa
- Department of Psychiatry, University of California at Davis, 2230 Stockton Boulevard, Sacramento, CA 95817, USA
| | - Jose Lasalde-Dominicci
- Department of Biology, University of Puerto Rico, Río Piedras Campus, P.O. Box 23360, San Juan 00931-3360, Puerto Rico
| |
Collapse
|
10
|
Harrod SB, Booze RM, Mactutus CF. Sex differences in nicotine levels following repeated intravenous injection in rats are attenuated by gonadectomy. Pharmacol Biochem Behav 2006; 86:32-6. [PMID: 17270256 PMCID: PMC3267293 DOI: 10.1016/j.pbb.2006.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 12/12/2006] [Accepted: 12/13/2006] [Indexed: 11/23/2022]
Abstract
Previous research demonstrates that repeated intravenous (i.v.) nicotine injection resulted in increased locomotor sensitization in female relative to male rats. In order to determine if increased nicotine levels are detected in females compared to males the present experiment examined the plasma nicotine levels of male, female, castrated (CAST), and ovariectomized (OVX) rats (n=7-11 rats/group) following repeated i.v. nicotine injection (50 microg/kg/injection). All rats received 14 i.v. nicotine injections, one/day. Approximately 1 min after the 14th nicotine injection, rats were rapidly decapitated and trunk blood was collected immediately. Gas chromatography revealed a sex difference in nicotine content: higher plasma nicotine levels were measured from female rats (>10 x increase) relative to males, and the sex difference was attenuated by gonadectomy. These data suggest that the sex difference in plasma nicotine levels is due to alteration in distribution or nicotine metabolism as a function of circulating gonadal hormones. These findings indicate that gonadal hormones may influence nicotine pharmacokinetics and therefore nicotine-induced sex differences in behavior.
Collapse
Affiliation(s)
- Steven B Harrod
- Department of Psychology, University of South Carolina, Columbia 29208, United States.
| | | | | |
Collapse
|
11
|
Brewer BG, Roberts AM, Rowell PP. Short-term distribution of nicotine in the rat lung. Drug Alcohol Depend 2004; 75:193-8. [PMID: 15276225 DOI: 10.1016/j.drugalcdep.2004.02.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2003] [Revised: 02/16/2004] [Accepted: 02/16/2004] [Indexed: 11/30/2022]
Abstract
Nicotine is a dibasic amine with a pK(a) of 8.0. At physiological pH roughly 1/4 of the compound is nonionized and able to cross membranes, most notably the alveolar membranes of the lung. Many models of nicotine addiction assume that the time it takes nicotine to pass from inspired air to the blood stream is negligible, resulting in a large peak or bolus in nicotine blood levels following each puff from a cigarette. However, the results of several previous studies have suggested that the lung may act as a short-term depot for nicotine. This was directly investigated in the present study. In anesthetized rats with open-chest and ventilated lungs, 0.4 mg [(3)H] ]nicotine in 50 microl was rapidly injected into the right ventricle of the heart and blood was sampled from the left ventricle. It was found that the [[(3)H]nicotine left the lungs at a significantly slower rate than [(14)C]dextran, a compound which remains in the plasma compartment (3.11% versus 7.71% injected/s for [(3)H]nicotine and [(14)C]dextran, respectively). In similar experiments, lung, heart and brain tissue were obtained at 5s intervals. Significant [(3)H]nicotine remained in the lung throughout the 40 s period, with lung tissue nicotine greater than brain at all time points. These results indicate that the lung may act as a short-term depot for nicotine, delaying and depressing its appearance in the systemic arterial circulation.
Collapse
Affiliation(s)
- Bradley G Brewer
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40292, USA
| | | | | |
Collapse
|
12
|
Shiffman S, Hughes JR, Pillitteri JL, Burton SL. Persistent use of nicotine replacement therapy: an analysis of actual purchase patterns in a population based sample. Tob Control 2003; 12:310-6. [PMID: 12958394 PMCID: PMC1747733 DOI: 10.1136/tc.12.3.310] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND In 1996, the US Food and Drug Administration (FDA) approved switching nicotine gum and patch from prescription to over-the-counter (OTC) status. Some expressed concerns that broader availability and lack of physician control might increase persistent use of nicotine replacement therapy (NRT)-that is, use beyond the period specified by the FDA approved label. OBJECTIVE To estimate the incidence of persistent use of OTC nicotine gum and patch for periods of > 3 months, > or = 6 months, > or = 12 months, and > or 24 months. DESIGN Analysis of NRT purchase patterns in data from a population based panel of US households that electronically scanned all household purchases between January 1997 and March 2000. SUBJECTS In a national panel of 40,000 US households, 2690 recorded NRT purchases. RESULTS Among 805 households that purchased nicotine gum, 2.3% of new purchase incidents led to continuous monthly purchase of gum for > or = 6 months. For nicotine patches (2050 households) the percentage was 0.9%. For both gum and patch, the incidence of persistent purchase dropped below 0.4% by 24 months. Allowing one month gaps within a "continuous" purchase run resulted in increased estimates (for gum: 6.7% for > or = 6 months and 1.0% for > or = 24 months; for patch: 1.7% for > or = 6 months and 0.05% for > or = 24 months). CONCLUSION Persistent use of nicotine gum and patch is very rare and has not increased with the transition to OTC use, despite removal of physician oversight.
Collapse
Affiliation(s)
- S Shiffman
- Pinney Associates and University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
| | | | | | | |
Collapse
|