Determination of nicotine N-1-glucuronide, a quaternary N-glucuronide conjugate, in human biological samples

[Methyl-d3]-N-1-beta-D-glucopyranosyl-(+/-)-nicotinium inner salt ((+/-)-[methyl-d3]nicotine N-1-glucuronide) was synthesized from (+/-)-[methyl-d3]nicotine via reaction with methyl-2,3,4-tri-O-acetyl-1-bromodeoxy-alpha-D-glucopyranouronate, followed by deprotection with 1 M aqueous NaOH and purification by preparative TLC. Nicotine N-glucuronide was identified and determined directly in smokers' urine. A solid phase extraction method was used to partially isolate the material from urine. Subsequent determination was by thermospray-LC/MS using the synthetic d3-labeled nicotine N-glucuronide as internal standard. The identified urinary component had the same retention time as a synthetic standard and gave the same mass spectrum. The thermospray mass spectrum was characterized from the protonated molecular ion (m/z 339) and the protonated aglycone ion (m/z 163). Quantitative results from this direct method were compared with those from an indirect method, which calculated the nicotine glucuronide in the biological sample from the amount of nicotine released following treatment of the sample with the deconjugating enzyme, beta-glucuronidase. On average, the concentration of nicotine N-glucuronide determined by the direct method was 34% greater than that determined by the indirect method. Concentrations of nicotine N-glucuronide in urine ranged from 2.2 to 7.6 nmol/ml with a limit of detection of 1.3 nmol/ml.

Tobacco cessation, the dental profession, and the role of dental education

This article describes the development of a comprehensive, interdisciplinary, tobacco cessation program based on twenty years of experience at the Indiana University (IU) School of Dentistry. It reviews the relationship between tobacco use and oral health, the nature of nicotine addiction and cessation approaches involving nicotine replacement therapy. In the early 1980s, tobacco control curriculum and cessation guidelines were introduced at the IU School of Dentistry and cooperative efforts initiated with other U.S. and Canadian dental schools. During the past decade, an interdisciplinary Nicotine Dependence Program has been developed to serve outpatients receiving treatment at all hospitals on the IU Medical Center campus. It is hoped that the models described here will be of value to other dental schools developing educational curricula and tobacco control and cessation programs.

Availability of smoking cessation resources for U.S. Army general medical officers

Adequate resources are a necessity in providing effective smoking cessation interventions to active duty soldiers. The availability of smoking cessation resources was measured by a survey of Army general medical officers (GMOs). Questionnaires were successfully mailed to 232 Army GMOs, which was the entire population of this group in 1997. One hundred fifty GMOs (65%) returned the questionnaire voluntarily and anonymously. Fifty-three percent of GMOs identified the nicotine patch as a formulary item. All responders indicated that some form of nicotine replacement was available on formulary or for purchase in the area. Eighty-two percent of GMOs reported that group smoking cessation programs were available. The widespread availability of group smoking cessation programs may reflect an emphasis on this strategy by the Army's health promotion program. Additional attention needs to address the availability of nicotine replacement items and other adjunctive medications without cost to the beneficiary at military installations.

Effectiveness of a minimal contact smoking cessation program for Dutch general practitioners: a randomized controlled trial

BACKGROUND

Until recently, Dutch general practitioners contributed little to tobacco control. This is due to several factors, among which is the lack of a feasible intervention program for adult smokers. Such a minimal contact behavioral intervention, using the Stage-of-Change concept, is now available. Effectiveness was tested in a randomized trial.

METHOD

Twenty-two general practitioners and their practice assistants were trained in applying the program. In all, 530 smoking patients were enrolled, randomly assigned to either the intervention or the usual treatment condition. Analysis of treatment effects was performed with logistic regression analysis. In a backward stepwise procedure confounding effects of baseline differences were eliminated.

RESULTS

At 12-month follow-up, self-reported abstinence rates (including nonrespondents as smokers) differed significantly between intervention subjects and controls: 13.4 vs 7.3% point prevalence (odds ratio 1.51, P < 0.05). An analysis of consecutive abstinence, defined as being abstinent at both 6- and 12-month follow-up, showed that 8.2% of the intervention group compared to 3.1% of the controls had sustained abstinence for more than 6 months (odds ratio 3.04, P < 0.001).

CONCLUSIONS

Results indicate that an effective smoking cessation program for use in Dutch general practice, already shown to be feasible, is now available. Outcomes are generally consistent with recent international literature.

Chain-lengthened and imidazoline analogues of nicotine

Analogues of nicotine (1) and azanicotine (3) were prepared with an additional methylene group inserted between the two rings (i.e., homonicotine and homoazanicotine; 6 and 5, respectively). Although 6 (Ki = 3110 nM) and 3 (Ki = 206 nM) bind at nACh receptors with > or = 100-fold lower affinity than nicotine (Ki = 2.1 nM), 5 displays high affinity (Ki = 7.8 nM). Like nicotine (ED50 = 12 microg/mouse), both 3 and 5 (ED50 = 21 and 19 microg/mouse, respectively) produced antinociceptive activity in the tail-flick assay following intrathecal administration. The antinociceptive actions of 3 and 5, unlike those of nicotine, were not antagonized by mecamylamine. Compounds 3 and 5 might represent novel analgesic agents that act via a non-nicotinic mechanism, or via a nicotinic mechanism that is distinct from that mediating the antinociceptive actions of nicotine.

Neonicotinoid insecticides: molecular features conferring selectivity for insect versus mammalian nicotinic receptors

The favorable selective toxicity of neonicotinoid insecticides (represented here by imidacloprid, thiacloprid, and a nitromethylene analogue) for insects versus mammals is not shared by three of their N-unsubstituted imine derivatives or by nicotine or epibatidine. The same selectivity pattern is evident at the receptor level, i.e., the insect nicotinic acetylcholine receptor (nAChR) versus mammalian nAChR subtypes (alpha1, alpha3, alpha4, and alpha7) assayed independently. The insect-selective compounds are not protonated with a nitroimine, cyanoimine, or nitromethylene group and the mammalian-selective compounds are ionized at physiological pH. We propose that the negatively charged tip of the nitro or cyano group (not a partial positive charge at imidazolidine N-1 as suggested earlier) interacts with a putative cationic subsite of the insect nAChR. This contrasts with the mammalian nAChRs where the iminium cation (+C-NH2 <--> C =+NH2) of the neonicotinoid imine derivatives or ammonium nitrogen of nicotine or epibatidine interacts with the anionic subsite.

Enhancement of haloperidol-induced catalepsy by nicotine: an investigation of possible mechanisms

Nicotine has been reported to potentiate the cataleptic effect of the dopamine receptor antagonist haloperidol in rats. This effect is paradoxical, since nicotine alone tends to increase nigrostriatal dopamine release. In the present experiments, a pro-cataleptic effect of nicotine was confirmed statistically but was small and variable. Three potential mechanisms underlying this effect were investigated. (i) Desensitization of brain nicotinic receptors appears to make little if any contribution to the pro-cataleptic effect of nicotine, insofar as the latter was not mimicked by two centrally active nicotinic antagonists (mecamylamine and chlorisondamine). (ii) Depolarization inactivation resulting from combined treatment with haloperidol and nicotine does not appear to be critical, since the pro-cataleptic effect of nicotine was not enhanced by chronic haloperidol administration, a treatment designed to enhance depolarization inactivation. (iii) The slow emergence and persistence of the acute pro-cataleptic effect of nicotine suggested possible mediation by a nicotine metabolite. However, neither cotinine nor nornicotine, the principal pharmacologically-active metabolites of nicotine, exerted a significant pro-cataleptic effect. In conclusion, the pro-cataleptic effect of nicotine was weak and variable in the present study, and its mechanism remains obscure.

Nicotine is more reinforcing in smokers with a past history of alcoholism than in smokers without this history

BACKGROUND

Whether smokers with a past history (PH) but not current history of alcohol dependence are more nicotine dependent than smokers with no such history (NH) is unclear. The present study was an experimental test of this hypothesis.

METHOD

Twenty PH and 10 NH smokers abstained from smoking for 16 hr on each of 4 days. On each of 3 days, participants received three doses per day of 0, 2, or 4 mg nicotine gum in a within-subjects, randomized, double-blind, crossover design. To examine subjective effects, participants completed the Profile of Mood States, Addiction Research Inventory, and other ratings before and after each dose. To examine nicotine reinforcement, participants reported preference among the gums, reported on money versus gum choices, and, on the 4th day, underwent a double-blind self-administration test.

RESULTS

Across the 21 subjective measures, with one exception, PH and NH smokers did not differ in subjective response to nicotine. However, across all three reinforcement measures, nicotine was a more potent reinforcer in PH than NH smokers.

CONCLUSIONS

These results provide a behavioral mechanism to explain prior findings that PH smokers are more nicotine dependent than NH smokers.

Smoking cessation with four nicotine replacement regimes in a lung clinic

Smoking cessation is a key intervention for prevention of several lung diseases. The aim of the present study was to compare the effect of smoking cessation with nicotine replacement in a lung clinic in a low resource set-up suitable for implementation in other lung clinics. This was an open, randomized trial with 4 different nicotine replacement regimes combined with minimal behavioural support in daily routine. A total of 446 smokers (>9 cigarettes x day(-1)) were allocated to a nurse-conducted smoking cessation programme with 4 treatment arms: a 5-mg nicotine patch ("placebo"), a 15-mg nicotine patch, nicotine inhaler, and a 15-mg nicotine patch plus nicotine inhaler. Recommended use of the nicotine products were 3 months with the possibility of continuing use up to 9 months on an individual basis. Individual follow-up studies were scheduled after 2 and 6 weeks, 3, 6, 9 and 12 months. The 12-month point prevalence was 6% (5-mg patch (placebo)), 16% (15-mg patch) (p<0.05), 9% (inhaler) and 11% (15-mg patch plus inhaler), respectively. To conclude, the set-up investigated in this study which included minimal behavioural support with nicotine patches should be evaluated in other lung clinics, as it doubled success rate when compared to a placebo with a 1-yr point prevalence of 16% and also the resources used are limited.

Telephone counseling as adjuvant treatment for nicotine replacement therapy in a "real-world" setting

BACKGROUND

Physicians prescribing nicotine replacement therapy (NRT), or health plans covering NRT, often want their patients to receive adjuvant behavioral treatment. However, how to do that in a "real world" is unclear. This paper reports results from a public health program that uses proactive telephone counseling as support for physician advice and provides adjuvant treatment for NRT users.

METHODS

Participants were NRT users (N = 8,832) who called the California Smokers' Helpline, a statewide cessation service that provides proactive counseling, one session before NRT use and multisessions after the smokers received NRT. After receiving NRT, some participants discontinued the counseling while others continued with follow-up sessions. A subset of the 8,832 participants (n = 664) was interviewed 13 months later for quitting status.

RESULTS

After receiving NRT, 79% of the participants continued with counseling and received 4.2 sessions on average, while 21% of them received only one session. Overall, 82.8% of all participants made a quit attempt. Nicotine patch users were more likely to make an attempt than nicotine gum users (85.2% vs 66.3%), but the relapse probability was the same for these attempts. Those who received multiple counseling were more likely to make an attempt than those receiving single counseling (84.4% vs 77.1%) and were more likely to stay quit for 1 year (25.6% vs 16.1%).

CONCLUSIONS

Proactive telephone counseling is a promising adjuvant treatment for NRT users in a "real-world" setting: a convenient referral service for supporting health plans or physicians who advise their patients to quit smoking.

Nornicotine pretreatment decreases intravenous nicotine self-administration in rats

RATIONALE

Nicotine has been shown to be effective as a treatment for reducing tobacco dependence. However, few studies have examined the effect of other nicotinic agonists to determine if they can also decrease nicotine self-administration.

OBJECTIVE

The present study determined if nornicotine, a tobacco alkaloid and major nicotine metabolite in brain, could reduce nicotine self-administration in rats.

METHODS

Each rat was prepared with an indwelling jugular catheter and trained to self-administer intravenous nicotine (0.03 mg/kg per infusion). After nicotine self-administration stabilized, rats were pretreated with either (-)-nicotine (0, 0.1, 0.3, and 1.0 mg/kg free base) or (+/-)-nornicotine (0, 1, 3, 5.6, and 10.0 mg/kg free base) and assessed for nicotine self-administration. A separate group of rats was maintained on sucrose reinforced responding and pretreated with nornicotine to determine the specificity of the pretreatment effect. In another group of rats, the time course of the pretreatment effect of either (-)-nicotine (0.56 and 1.0 mg/kg) or (+/-)-nornicotine (5.6 and 10.0 mg/kg) was examined.

RESULTS

Nicotine and nornicotine each produced a dose-dependent decrease in nicotine self-administration. Furthermore, the decrease in nicotine self-administration in response to the 5.6 mg/kg nornicotine pretreatment was specific to nicotine self-administration, as this dose did not decrease sucrose reinforced responding in tolerant animals. In addition, within the dose range tested, the suppressant effect of nornicotine had a two-fold longer duration than that of nicotine (120 versus 60 min).

CONCLUSION

These results suggest that nornicotine may be an effective treatment for tobacco dependence.

Acute nicotine administration in Alzheimer's disease: an exploratory EEG study

Previous findings of cognitive deficits and EEG slowing in Alzheimer's patients, together with independent reports of the performance enhancing and electrocortical activating properties of nicotine in normal adults, stimulated this study to examine the acute effects of nicotine on spectrum-analyzed EEG in patients with dementia of the Alzheimer type (DAT). Thirteen patients, 6 currently receiving cholinesterase inhibitor treatment and the remaining being medication free, were administered 2 mg of nicotine polacrilex under randomized, placebo-controlled conditions. Compared to age-regressed EEG norms, the pretreatment EEG spectrums of patients in general were characterized by excessive slow (delta and theta)-wave power, diminished fast (alpha and beta)-wave power and slow mean alpha and total band frequencies. Although postnicotine EEG indices remained within the abnormal range, nicotine, compared to placebo, significantly shifted EEG towards normal values by reducing slow wave (relative delta and theta) power and augmenting fast (relative alpha-1, alpha-2, beta-1) wave power. No differences were observed between treated and nontreated patients in response to nicotine. The results are discussed in relation to cholinergic and brain arousal systems and their relationship to cognitive processes.

Development of ligands for in vivo imaging of cerebral nicotinic receptors

Nicotinic acetylcholine receptors (nAChRs) mediate a variety of brain functions. Findings from postmortem studies and clinical investigations have implicated them in the pathophysiology and treatment of Alzheimer's and Parkinson's diseases and other CNS disorders (e.g. Tourette's syndrome, epilepsy, nicotine dependence). Therefore, it ultimately might be useful to image nAChRs noninvasively for diagnosis, for studies on how changes in nAChRs might contribute to cerebral disorders, for development of therapies targeted at nAChRs, and to monitor the effects of such treatments. To date, only (S)-(-)-nicotine, radiolabeled with 11C, has been used for external imaging of nAChRs in human subjects. Since this radiotracer presents drawbacks, new ligands, with more favorable properties, have been synthesized and tested. Three general classes of compounds, namely, nicotine and its analogs, epibatidine and related compounds, and 3-pyridyl ether compounds, including A-85380, have been evaluated. Analogs of A-85380 appear to be the most promising candidates because of their low toxicity and high selectivity for the alpha4beta2 subtype of nAChRs.

Synthesis of two conformationally constrained analogues of the minor tobacco alkaloid anabasine

The anabasine analogues spiro[4-azaindan-1,2'-piperidine] (7) and spiro[6-azaindan-1,2'-piperidine] (8) have been prepared. A series of palladium-catalyzed reactions, where an intramolecular cyclization constituted a key reaction, were utilized for the preparation of the two target compounds.

The activation and inhibition of human nicotinic acetylcholine receptor by RJR-2403 indicate a selectivity for the alpha4beta2 receptor subtype

Human nicotinic acetylcholine (ACh) receptor subtypes expressed in Xenopus oocytes were characterized in terms of their activation by the experimental agonist RJR-2403. Responses to RJR-2403 were compared with those evoked by ACh and nicotine. These agonists were also characterized in terms of whether application of the drugs had the effect of producing a residual inhibition that was manifest as a decrease in subsequent control responses to ACh measured 5 min after the washout of the drug. For the activation of alpha4beta2 receptors, RJR-2403 had an efficacy equivalent to that of ACh and was more potent than ACh. RJR-2403 was less efficacious than ACh for other human receptor subtypes, suggesting that it is a partial agonist for all these receptors. Nicotine activated peak currents in human alpha4beta2 and alpha3beta2 receptors that were 85 and 50% of the respective ACh maximum responses. Nicotine was an efficacious activator of human alpha7 receptors, with a potency similar to ACh, whereas RJR-2403 had very low potency and efficacy for these receptors. At concentrations of <1 mM, RJR-2403 did not produce any residual inhibition of subsequent ACh responses for any receptor subtype. In contrast, nicotine produced profound residual inhibition of human alpha4beta2, alpha3beta2, and alpha7 receptors with IC(50) values of 150, 200, and 150 microM, respectively. Co-expression of the human alpha5 subunit with alpha3 and beta2 subunits had the effect of producing protracted responses to ACh and increasing residual inhibition by ACh and nicotine but not RJR-2403. In conclusion, our results, presented in the context of the complex pharmacology of nicotine for both activating and inhibiting neuronal nicotinic receptor subtypes, suggest that RJR-2403 will be a potent and relatively selective activator of human alpha4beta2 receptors.

The efficacy of computer-tailored smoking cessation material as a supplement to nicotine polacrilex gum therapy

BACKGROUND

Standard, generic self-help materials have been largely ineffective as behavioral treatments for smoking cessation. In contrast, self-help programs tailored to the needs of specific smokers have shown promise in facilitating quitting.

OBJECTIVE

To evaluate the incremental efficacy of the Committed Quitters Program (CQP), a set of computer-tailored materials offered to purchasers of nicotine polacrilex gum, compared with a briefuntailored user's guide and audiotape, both as supplements to nicotine replacement therapy.

METHODS

We conducted a randomized, open-label trial with 3 parallel arms. Subjects were smokers who purchased 2- or 4-mg nicotine polacrilex gum and called the CQP toll-free enrollment line. Three thousand six hundred twenty-seven subjects consented to participate in 1 of 3 study arms: (1) those receiving the CQP materials (CQP group, n= 1,217), (2) those receiving CQP materials and an outbound telephone call (CQP + C group, n= 1,207); and (3) those receiving no supplemental intervention beyond the user's guide and audiotape that were prepackaged with the nicotine polacrilex gum (UG group, n= 1,203). Twenty-eight-day continuous abstinence rates were assessed by telephone interviews at 6 weeks and 10-week continuous rates at 12 weeks into treatment.

RESULTS

Abstinence rates among respondents at the 6- and 12-week assessments were significantly higher for the CQP (36.2% and 27.6%) and CQP + C (35.5% and 27.3%) groups compared with the UG group (24.7% and 17.7%) at both intervals. The quit rates for the CQP and CQP + C groups were almost identical.

CONCLUSIONS

The CQP proved to be an effective behavioral treatment, enhancing quit rates over and above nicotine replacement therapy and a brief untailored written guide and audiotape.

A concise synthetic pathway for trans-metanicotine analogues

A convenient pathway for synthesis of trans-metanicotine analogues was developed. trans-Metanicotine, a subtype (alpha4beta2)-selective ligand for neuronal nicotinic acetylcholine receptor, is under clinical phase for Alzheimer's disease. Zn-mediated allylation of allyl bromide and acetaldehyde followed by Heck reaction with 3-bromopyridine gave 5-pyridin-3-yl-pent-4-en-3-ol (2). Tosylation of 5-pyridin-3-yl-pent-4-en-3-ol followed by substitution reaction with methylamine in sealed tube gave methyl-(1-methyl-4-pyridin-3-yl-but-3-enyl)-amine (4) in good yields. Thus, trans-metanicotine analogues modified at the alpha-position of the methylamino group with various functional groups can be obtained in 4 steps.

Treatment of nicotine addiction

The best available data show smoking to be by far the most important cause of disease and death in our society, contributing to an average of 1000 deaths every day. Although a large majority of current smokers express a desire to quit, the majority of "self-help" attempts to quit are not successful. Further, most smokers indicate never having received advice on cessation from healthcare providers. The combination of pharmacotherapy and behavioral interventions, even on a minimal level, have been shown to be effective in cessation. Such strategies are certainly highly cost-effective, given the enormous costs to society of smoking-related illnesses. Therefore, it is important that all healthcare providers provide at least some form of smoking cessation programs for their patients.

Synthesis and in vivo evaluation of (E)-N-[(11)C]Methyl-4- (3-pyridinyl)-3-butene-1-amine ([(11)C]metanicotine) as a nicotinic receptor radioligand

(E)-N-[(11)C]Methyl-4-(3-pyridinyl)-3-butene-1-amine ([(11)C]metanicotine), a high affinity (K(i) = 16 nM) CNS-selective nicotinic agonist, was prepared by the [(11)C]alkylation of the desmethyl precursor with [(11)C]methyl trifluoromethanesulfonate. In vivo distribution studies in mice demonstrated good blood brain permeability but essentially uniform regional brain distribution and no evidence of specific binding to nicotinic cholinergic receptors. Identical results were obtained in an imaging study performed in a monkey brain. Therefore, despite literature reports supporting the use of metanicotine as a cognition enhancing nicotinic agonist, (E)-N-[(11)C]methyl-4-(3-pyridinyl)-3-butene-1-amine does not appear to be a suitable candidate for in vivo imaging studies of nicotinic acetylcholine receptors in the mammalian brain.

A comparison of the abuse liability and dependence potential of nicotine patch, gum, spray and inhaler

RATIONALE

Nicotine replacement therapy (NRT) in varying forms is becoming widely used. Clinicians, therapists and regulatory authorities are interested in the abuse liability and dependence potential of the different forms.

OBJECTIVES

To compare the abuse liability and dependence potential of nicotine gum, transdermal patch, spray and inhaler.

METHODS

504 male and female smokers seeking help with stopping smoking were randomly allocated to the four products. Measures were taken at the designated quit date, then 1 week, 4 weeks, 12 weeks and 15 weeks later. Smokers were advised to use the product for up to 12 weeks. Those still using the product at the 12-week visit were advised to cease use by week 14. Measures included: pleasantness and satisfaction ratings at weeks 1 and 4 (used as a marker of abuse liability); ratings of feeling dependent on NRT at weeks 1, 4, 12 and 15 (used as a marker of subjective dependence); mood and physical symptoms ratings at weeks 12 and 15 (the change being used to assess physical dependence on NRT), continued usage of NRT at week 15 (used as an marker of behavioural dependence).

RESULTS

Average ratings of pleasantness were low. The nicotine patch was rated as less unpleasant to use than all other products. There were no significant differences between the products in terms of satisfaction or subjective dependence except at week 15 when no patch users rated themselves as dependent. Continued use of NRT at week 15 was related to rate of delivery of nicotine from the products - 2% for patch, 7% for gum and inhaler, 10% for spray (P<0.05 for linear association). Among those