Atomoxetine monotherapy compared with combination therapy for the treatment of ADHD: a retrospective chart review study.

OBJECTIVE: To analyze Clinical Global Impression-Severity (CGI-S) in ADHD patients treated with atomoxetine (ATX) monotherapy versus ATX combination therapy with another ADHD-indicated medication. METHODS: This was a 2-site retrospective observational chart review study of child and adult ADHD patients, not necessarily treatment naïve, but treated ≥50 days post baseline with an endpoint assessment. To adjust for measured confounders, monotherapy (n = 77) versus combination (n = 108) cohort comparisons were performed using propensity score stratification and adjusted ANCOVA. RESULTS: There were no significant baseline cohort differences after propensity stratification. CGI-S scores after a mean 264 days of treatment were not statistically significantly different between cohorts, with no cohort differences observed in any assessed symptom subcategory. The cohorts were similar in discontinuation due to any reason, adverse event, and lack of efficacy. CONCLUSION: ATX combination therapy showed no evidence of additional benefit over ATX monotherapy in the treatment of ADHD in a community-based setting.

A phase 2, placebo-controlled study of the opioid receptor antagonist LY2196044 for the treatment of alcohol dependence.

BACKGROUND: Endogenous opioid-mediated reward pathways may play a role in the development and maintenance of alcohol dependence. This study tested whether LY2196044, an opioid receptor antagonist, in combination with medical management would reduce drinking in alcohol-dependent patients. METHODS: This was a multicenter, outpatient, randomized, double-blind, parallel, and placebo-controlled trial with a 16-week treatment period. Patients (N = 375) were alcohol-dependent, treatment-seeking adults. Patients were randomly assigned to once-daily LY2196044 (final doses of 125 or 250 mg/d) or placebo. DNA samples were collected at baseline. At each visit, patients underwent safety assessments, laboratory testing, efficacy measures, and medical management. Blood samples were also obtained for pharmacokinetic testing. The primary measure was the change from baseline in the percent heavy drinking days (HDD). Secondary efficacy measures were percent days abstinent per month and number of drinks per day. RESULTS: The treatment difference in change from baseline in % HDD between LY2196044 and placebo was not statistically significant (-43.02 vs. -38.72%, respectively; p = 0.12). There was a trend toward greater change from baseline in the percent days abstinent per month for the LY2196044 group compared with the placebo group (33.49 vs. 28.12%, respectively; p = 0.051). The decrease from baseline for mean number of drinks per day was statistically significantly greater in the LY2196044 group compared with the placebo group (-5.37 vs. -4.66 drinks per day, respectively; p = 0.013). LY2196044-treated patients who were dopamine receptor type 4-variable number tandem repeat L carriers had greater reductions in % HDD (p = 0.0565), increased percent days abstinent (p = 0.0496), and reduced drinks per day (p = 0.0069) than placebo-treated L carriers. The safety profile for LY2196044 appeared similar to that of other opioid antagonists. CONCLUSIONS: The results from this proof-of-concept clinical trial warrant further evaluation of LY2196044 for the treatment of alcohol dependence.

Real-world use patterns of olanzapine long-acting injection in the United States: comparison to the recommended dosing strategy.

OBJECTIVE: Recommended doses for olanzapine long-acting injection (olanzapine LAI) are 150 mg/2 weeks, 210 mg/2 weeks, 300 mg/2 or 4 weeks, and 405 mg/4 weeks. This analysis evaluated the dosing and interval patterns to compare the actual dosing patterns with the recommended dosing strategy. RESEARCH DESIGN AND METHODS: These data, from March 2010 through September 2011, were collected as part of a Risk Evaluation and Mitigation Strategy mandatory patient registry that captures all post-approval olanzapine injections in the US. This registry includes both active and inactive (60 + days since last injection) patients. RESULTS: All patients with at least one olanzapine injection were included (n = 1694). The mean number of injections received was 6.6 (range of 1-40). The most frequent numbers of injections were one (26.3%) and two (12.9%). For the 11,228 olanzapine injections, the most common doses were 300 mg and 405 mg, accounting for 92.9% of injections. Although the most common time intervals between injections was about 14 days for 150 mg, 210 mg, and 300 mg, and about 28 days for 405 mg, the intervals ranged from less than 10 to more than 60 days for all doses. Among active patients (48.2% of registry), 68.2% had >120 days of treatment with any dose, and the number of days since the last injection was around 2 weeks or less for 61.2% of patients, around 3 weeks for 16.5% of patients, and around 4 weeks for 7.1% of patients. Among inactive patients (51.8% of registry), 48.6% had <30 days of treatment. For the pattern of the first five injections, most patients (70.9%) received four subsequent injections of the same dose as their initial injection. CONCLUSIONS: This registry will continue to change. There is a broad range in time between injections. Most patients continue to receive the same initial dose instead of switching to a maintenance dose. This may suggest that some clinicians are not reassessing the dose after the initial starting dose because the patient was stabilized on olanzapine oral before beginning olanzapine long-acting injection. The study is limited by a database that does not include reasons for dose and dosing interval decisions or reasons for delaying or discontinuing treatment.

A review of the abuse potential assessment of atomoxetine: a nonstimulant medication for attention-deficit/hyperactivity disorder.

RATIONALE: Treatment of attention-deficit/hyperactivity disorder (ADHD) has for many years relied on psychostimulants, particularly various formulations of amphetamines and methylphenidate. These are central nervous system stimulants and are scheduled because of their abuse potential. Atomoxetine (atomoxetine hydrochloride; Strattera®) was approved in 2002 for treatment of ADHD, and was the first nonstimulant medication approved for this disorder. It was classified as an unscheduled medication indicating a low potential for abuse. However, the abuse potential of atomoxetine has not been reviewed. OBJECTIVES: In this article, we review the evidence regarding abuse potential of atomoxetine, a selective inhibitor of the presynaptic norepinephrine transporter, which is unscheduled/unrestricted in all countries where it is approved. METHODS: Results from receptor binding, in vitro electrophysiology, in vivo microdialysis, preclinical behavioral, and human laboratory studies have been reviewed. RESULTS: Atomoxetine has no appreciable affinity for, or action at, central receptors through which drugs of abuse typically act, i.e., dopamine transporters, GABA(A) receptors, and opioid µ receptors. In behavioral experiments in rodents, atomoxetine does not increase locomotor activity, and in drug discrimination studies, its profile is similar to that of drugs without abuse potential. Atomoxetine does not serve as a reinforcer in monkey self-administration studies, and human laboratory studies suggest that atomoxetine does not induce subjective effects indicative of abuse. CONCLUSION: Neurochemical, preclinical, and early clinical studies predicted and supported a lack of abuse potential of atomoxetine, which is consistent with the clinical trial and postmarketing spontaneous event data in the past 10 years.

Effects of olanzapine long-acting injection on levels of functioning among acutely ill patients with schizophrenia.

OBJECTIVE: To assess the effects of olanzapine long-acting injection (olanzapine-LAI) on levels of functioning in acutely ill patients with schizophrenia. RESEARCH DESIGN AND METHODS: During this 8-week randomized, double-blind, placebo-controlled trial, 404 inpatients were randomized to four treatment arms (olanzapine-LAI 210 mg/2 weeks = 106; olanzapine-LAI 300 mg/2 weeks = 100; olanzapine-LAI 405 mg/4 weeks = 100; placebo = 98). Also, data from the three active dosing arms were combined and compared to placebo data. CLINICAL TRIAL REGISTRATION: NCT00088478. MAIN OUTCOME MEASURES: The treatment group comparison of mean change from baseline to endpoint in the total score and four subdomains of the Heinrichs-Carpenter Quality of Life Scale (QLS) and in the 2 summary scores and 8 subscale scores of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) were assessed using an ANOVA model. RESULTS: All three olanzapine-LAI treatment groups and the combined olanzapine-LAI group were superior to placebo on the QLS total score (all p-values < 0.01) and the Intrapsychic Foundations subdomain (all p-values < 0.02). Olanzapine-LAI 210 mg/2 weeks (p < 0.001), 300 mg/2 weeks (p = 0.006), and the combined olanzapine-LAI group (p = 0.003) were superior to placebo on the Interpersonal Relations subdomain. The 300 mg/2 weeks group (p = 0.027) and the combined olanzapine-LAI group (p = 0.014) were also superior to placebo on the Instrumental Role subdomain. For the SF-36, the 300 mg/2 weeks and 405 mg/4 weeks olanzapine-LAI groups and the combined olanzapine-LAI group were superior to placebo on the Mental component score (all p-values < 0.05). Each olanzapine-LAI group and the combined group were superior on the Mental Health scale (all p-values < 0.05). Significant negative correlations between PANSS scores and measures of functioning indicate that as symptoms decreased, functioning increased. CONCLUSION: These results suggest that olanzapine-LAI may improve level of functioning in acutely ill patients with schizophrenia within 8 weeks of initiating treatment.

Reasons for continuing or discontinuing olanzapine in the treatment of schizophrenia from the perspectives of patients and clinicians.

BACKGROUND: The aim of this study was to assess the reasons for discontinuing or continuing olanzapine in patients with schizophrenia, from the perspectives of the patients and their clinicians. METHODS: The Reasons for Antipsychotic Discontinuation/Continuation (RAD) is a pair of questionnaires assessing these reasons from the perspectives of patients and their clinicians. Outpatients with schizophrenia (n = 199) who were not acutely ill participated in a 22-week open-label study of olanzapine from November 2006 to September 2008. Reasons for continuing or discontinuing olanzapine (on a five-point scale), along with the single most important reason and the top primary reasons, were identified. Concordance between reasons given by patients and clinicians was assessed. RESULTS: The top primary reasons for continuing olanzapine were patients' perceptions of improvement, improvement of positive symptoms, and improved functioning. The study discontinuation rate was low (30.2%), and only a subset of patients who discontinued reported reasons for medication discontinuation. The top primary reasons for discontinuing olanzapine were insufficient improvement or worsening of positive symptoms, adverse events, and insufficient improvement or worsening of negative symptoms. Ratings given by patients and clinicians were highly concordant. CONCLUSION: The main reason for continuing or discontinuing olanzapine appears to be medication efficacy, especially for positive symptoms. Reasons for medication discontinuation differ somewhat from reasons for continuation, with a high level of concordance between patient and clinician responses.

Decline in hospitalization risk and health care cost after initiation of depot antipsychotics in the treatment of schizophrenia.

PURPOSE: To assess change in hospitalization and cost of care from 6 months pre- to 6 months post-initiation on any depot antipsychotic among schizophrenia patients. PATIENTS AND METHODS: Using a large United States commercial claims and encounters database, patients younger than 65 years diagnosed with schizophrenia were identified. Patients initiated on a depot antipsychotic were studied in a mirror-image design to assess change in hospitalization rates, mean duration hospitalized, and hospitalization cost. McNemar's test and paired t-tests compared the proportions of patients hospitalized and the mean duration. Paired t-test and bootstrapping methods compared costs. RESULTS: In these patients (n = 147), psychiatric hospitalizations declined from 49.7% pre-initiation to 22.4% post-initiation (P < 0.001), and the mean hospitalized duration for psychiatric purposes numerically declined from 7.3 to 4.7 days (P = 0.05). Total health care costs declined from $11,111 to $7884 (P < 0.05) driven by reduction in costs for psychiatric hospitalizations from $5384 to $2538 (P < 0.05). CONCLUSION: Initiation of depot antipsychotic therapy appeared to be associated with a decline in hospitalization rates and costs. Current findings suggest that treatment with depot antipsychotics may be a cost-effective option for a subgroup of patients with schizophrenia who are at high risk of nonadherence with their oral antipsychotic medication regimen.

Effects of atomoxetine on self-reported high-risk behaviors and health-related quality of life in adolescents with ADHD.

OBJECTIVE: This study measured the effects of atomoxetine HCl on high-risk behaviors and health-related quality of life in adolescents with attention-deficit/hyperactivity disorder (ADHD), using a subgroup analysis of data from a previous clinical trial. RESEARCH DESIGN AND METHODS: In the base study, which was conducted at 26 sites in the United States, patients ages 13-16 years were randomized in a double-blind manner to atomoxetine treatment by one of two dose titration schedules for 8 weeks. Patients who responded to treatment were rerandomized to atomoxetine at a daily dose of 0.8 or 1.4 mg/kg for 40 weeks. Patients in the highest-risk quartile for each category of behavior or domain were included and the dosing groups combined. MAIN OUTCOME MEASURES: Efficacy measures included the Youth Risk Behavior Surveillance (YRBS) and Child Health and Illness Profile - Adolescent Edition (CHIP-AE). The YRBS has six categories of behavior, and the CHIP-AE has six domains. Data for mean change from baseline were analyzed using a last-observation-carried-forward analysis. RESULTS: A total of 267 patients were randomized, but the high-risk subgroup analyzed in the present study was much smaller (range of n = 5-68 per group). YRBS scores for tobacco use, unhealthful dietary behaviors, inadequate physical activity, and behaviors contributing to unintentional injuries showed statistically significant improvements (p < 0.05) by atomoxetine treatment at Week 8. At the end of the 40-week maintenance period, unhealthful dietary behaviors, inadequate physical activity, and behaviors contributing to unintentional injuries continued to show statistically significant improvements (p < 0.001). When the highest-risk quartile of the CHIP-AE data was analyzed, there were statistically significant improvements on all six domains after atomoxetine treatment at 8 weeks (p < 0.001) and on five of the six domains at 40 weeks (p < or = 0.01). CONCLUSIONS: Atomoxetine improved self-reported high-risk behaviors and overall health-related quality of life in adolescents with ADHD. Potential limitations of this study include small sample sizes and the fact that it involved a subgroup analysis, which is by nature hypothesis-generating. Further, well-controlled, prospective studies in larger and more heterogeneous ADHD populations, including older patients, are warranted to confirm or reject these findings.

Validation of the adult ADHD investigator symptom rating scale (AISRS).

OBJECTIVE: Validation of the Adult ADHD Investigator Symptom Rating Scale (AISRS) that measures aspects of ADHD in adults. METHOD: Psychometric properties of the AISRS total and AISRS subscales are analyzed and compared to the Conners' Adult Attention-Deficit/Hyperactivity Disorder Rating Scale-Investigator Rated: Screening Version (CAARS-Inv:SV) and the Clinical Global Impression-ADHD-Severity Scale using data from a placebo-controlled 6-month clinical trial of once-daily atomoxetine. RESULTS: The AISRS has high internal consistency, good convergent, and discriminant validities; modest divergent validity; and small ceiling and floor effects (

A randomized, controlled trial to assess the efficacy and safety of a transdermal delivery system of nicotine/mecamylamine in cigarette smokers.

AIMS: To determine the efficacy and safety of nicotine transdermal therapy co-administered with the nicotine antagonist, mecamylamine, compared to a nicotine transdermal patch alone (21 mg nicotine + 6 mg mecamylamine, 21 mg nicotine + 3 mg mecamylamine, and 21 mg nicotine + 0 mg mecamylamine). DESIGN: Multi-center (n = 4), double-blind, randomized, parallel group, repeat-dose study. SETTING: Clinical laboratory. PARTICIPANTS: A total of 540 subjects were enrolled into the study-135 from each of four sites; 180 patients in each of three treatment arms. INTERVENTION: Treatment was administered for the first 6 weeks of the 8-week study. Patients were instructed to continue smoking for the first 2 weeks of treatment. MEASUREMENTS: The primary efficacy parameter was 4-week continuous abstinence after the quit date, confirmed with an expired carbon monoxide of < 10 parts per million. FINDINGS: Analysis of the 4-week continuous abstinence for the intent-to-treat population showed overall rates of 29% (nicotine + 6 mg mecamylamine), 29% (nicotine + 3 mg mecamylamine) and 23% (nicotine only) using the slip definition which allows smoking in the first 2 weeks after the quit date. Statistical analyses revealed no significant treatment differences. Analyses using the strict definition (no smoking after the quit date) yielded similar non-significant group differences (29%, 27%, 26%). CONCLUSION: If adding mecamylamine to nicotine replacement therapy (NRT) improves the chances of success at stopping smoking, the results of this study suggest that the effect is very small.

Placebo-controlled study of the effects of atomoxetine on bladder control in children with nocturnal enuresis.

INTRODUCTION: Nocturnal enuresis is a condition in which children at least 5 years of age are incontinent of urine at night. Atomoxetine, a potent inhibitor of the presynaptic norepinephrine transporter, is used to treat attention-deficit/hyperactivity disorder (ADHD). This study tested the hypothesis that atomoxetine will provide significant therapeutic benefit for nocturnal enuresis in patients with the diagnosis of nocturnal enuresis. METHODS: Atomoxetine's efficacy for improving nocturnal enuresis was studied in 87 pediatric subjects using an outpatient, multicenter, randomized, double-blind, parallel, placebo-controlled study. Efficacy was determined by measuring the mean number of dry nights per week using an intent-to-treat analysis of the primary outcome measure, the Dry Night Log-Parent Report (DNL-PR), a daily parent diary. RESULTS: Baseline and end point DNL-PR data were available from 42 atomoxetine-treated and 41 placebo-treated subjects. Atomoxetine increased the average number of dry nights per week by 1.47 compared with .60 for placebo (F = 7.06; df = (1, 75); p = 0.01). Fifteen atomoxetine-treated subjects (35.7%) had an increase of at least 2 dry nights per week compared with only 6 (14.6%) placebo-treated subjects (Fisher's exact test; p = 0.042). There were no significant differences in adverse events between the groups. CONCLUSIONS: Compared with placebo, atomoxetine treatment was associated with a significant increase in dry nights in children with nocturnal enuresis.

Once-daily atomoxetine treatment for children with attention-deficit/hyperactivity disorder, including an assessment of evening and morning behavior: a double-blind, placebo-controlled trial.

OBJECTIVES: Atomoxetine seems to be as effective for treating attention-deficit/hyperactivity disorder (ADHD) when the daily dose is administered once in the morning as when the dose is divided and administered in the morning and evening. In the present study, the efficacy of atomoxetine administered once daily among children with ADHD was assessed throughout the day, including the evening and early morning. Another goal was to determine how early in treatment it was possible to discern a specific effect of the drug on ADHD symptoms. METHODS: This study was a randomized, multicenter, double-blind, placebo-controlled trial conducted at 12 outpatient sites in the United States. A total of 197 children, 6 to 12 years of age, who had been diagnosed as having ADHD, on the basis of the Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria, were randomized to receive 8 weeks of treatment with atomoxetine or placebo, dosed once daily in the mornings. ADHD symptoms were assessed with parent and investigator rating scales. The primary outcome measure was the Attention-Deficit/Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator-Administered and Scored total score. Daily parent assessments of children's home behaviors in the evening and early morning were recorded with an electronic data entry system. This instrument measures 11 specific morning or evening activities, including getting up and out of bed, doing or completing homework, and sitting through dinner. RESULTS: Seventy-one percent of the children enrolled were male, 69% met criteria for the combined subtype (both inattentive and hyperactive/impulsive symptoms), and the most common psychiatric comorbidity was oppositional defiant disorder (35%). Once-daily atomoxetine (final mean daily dose of 1.3 mg/kg) was significantly more effective than placebo in treating core symptoms of ADHD. Mean reductions in the Attention-Deficit/Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator-Administered and Scored total score were significantly greater for patients randomized to atomoxetine, beginning at the first visit after the initiation of treatment and continuing at all subsequent visits. Both inattentive and hyperactive/impulsive symptom clusters were significantly reduced with atomoxetine, compared with placebo. With continued treatment and dose titrations, core symptoms of ADHD continued to decrease throughout the 8-week study. Mean reductions in the daily parent assessment total scores for patients randomized to atomoxetine were superior during the first week, beginning with the first day of dosing, and were also superior at endpoint. Efficacy outcomes for the evening hours for atomoxetine-treated patients were superior to those for placebo-treated patients, as assessed with 2 different assessment scales. Decreases in the daily parent assessment morning subscores at endpoint showed a significant reduction in symptoms that lasted into the mornings. Rates of discontinuations attributable to adverse events were <5% for both groups. Adverse events reported significantly more frequently with atomoxetine were decreased appetite, somnolence, and fatigue. CONCLUSIONS: Among children 6 to 12 of age who had been diagnosed as having ADHD, once-daily administration of atomoxetine in the morning provided safe, rapid, continuous, symptom relief that lasted not only into the evening hours but also into the morning hours. Atomoxetine treatment was safe and well tolerated.

Transferring methadone-maintained outpatients to the buprenorphine sublingual tablet: a preliminary study.

There is no accepted algorithm to transfer opioid-dependent patients from methadone (METH) to its new alternative, buprenorphine (BUP). Five outpatients transferred (double blind, double dummy) from METH 60 mg/day (with one day at 45 mg) to BUP 8 mg s.l. tablet. Relative to METH maintenance, BUP decreased opioid agonist symptoms (transfer day 1) and increased withdrawal symptoms (days 1 and 2) and blood pressure (day 2). Self-reported heroin use did not increase from METH maintenance levels. It may be feasible to transfer outpatients on METH 60 mg/day to BUP 8 mg/day s.l. tablet, although this pilot protocol needs refinements to improve tolerability and clinical efficacy.

Efficacy of atomoxetine versus placebo in school-age girls with attention-deficit/hyperactivity disorder.

OBJECTIVE: The efficacy of atomoxetine was assessed in school-age girls with attention-deficit/hyperactivity disorder (ADHD). Atomoxetine is a potent inhibitor of the presynaptic norepinephrine transporter with minimal affinity for other noradrenergic receptors or for other neurotransmitter transporters or receptors. METHODS: A total of 291 children who were 7 to 13 years of age and met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for ADHD participated in 1 of 2 combined, double-blind, placebo-controlled, multisite, identical clinical trials. This intent-to-treat subset analysis examined the effects of atomoxetine versus placebo in 51 girls who were randomized to atomoxetine (n = 30) or placebo (n = 21) for 9 weeks. ADHD symptoms were assessed using parent- and investigator-rated scales. RESULTS: Atomoxetine was superior to placebo on the following measures: the Attention-Deficit Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator Administered and Scored Total Score; the Inattentive and Hyperactive/Impulsive subscales of the Attention-Deficit Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator Administered and Scored Total Score; the ADHD Index subscale of the Conners' Parent Rating Scale-Revised: Short Form; and the Clinical Global Impressions of Severity of ADHD. Statistically significant efficacy was seen 1 week after randomization and remained so for the duration of the study. One patient from each of the atomoxetine and placebo groups discontinued the study as a result of an adverse event. CONCLUSION: Atomoxetine was found to be effective and well tolerated for the treatment of ADHD in school-age girls.

Effects of buprenorphine sublingual tablet maintenance on opioid drug-seeking behavior by humans.

RATIONALE: Buprenorphine can decrease opioid self-administration by humans and animals, but its ability to decrease drug-seeking behavior and craving (i.e. motivational measures) among outpatient volunteers using clinically relevant dosing schedules has not been extensively studied. OBJECTIVES: We investigated whether daily versus alternating-day administration of high versus low buprenorphine doses influenced choice of, and operant responding for, hydromorphone versus money. METHODS: Fourteen heroin-dependent outpatients were maintained under four buprenorphine sublingual tablet (double blind) dose conditions using a within-subject, randomized crossover design. All participants received, for 2 weeks each, buprenorphine doses of 2 mg daily, 4 mg/placebo on alternating days, 16 mg daily, and 32 mg/placebo on alternating days. In each laboratory test session, participants chose between money ($2/choice) and drug (1/8 of total hydromorphone, 4 or 24 mg IM in different sessions) alternatives using an eight-trial non-independent progressive ratio schedule (FR 100, 200,.12,800). The drug dose and money amount earned was delivered after the end of the 2.5-h work period. RESULTS: Hydromorphone 24 mg was more reinforcing than 4 mg. Higher versus lower average buprenorphine doses (regardless of daily versus alternate-day schedule) significantly decreased hydromorphone 24 mg choice and increased money choice. Baseline heroin craving questionnaire scores predicted drug choice, and craving scores were significantly decreased by high-dose buprenorphine. CONCLUSIONS: High-dose buprenorphine attenuated opioid drug-seeking behavior, heroin craving self-reports and increased sensitivity to alternative reinforcement. These beneficial effects were retained when high-dose buprenorphine was administered on alternate days.

Pharmacologic Determinants of Tobacco Dependence.

Nicotine is one of the most widely abused psychoactive drugs and far more people trying it progress to regular use than those trying heroin, cocaine, or alcohol. Since the early 20th century, it has been understood that tobacco use is driven largely by nicotine's pharmacological actions. Nicotine produces reinforcing effects, tolerance and physical dependence, and pharmacological effects that smokers enjoy, such as modulation of mood, appetite, and task performance. Pharmacokinetic properties of tobacco-based nicotine products optimize abuse potential. Cigarette smoke inhalation delivers high nicotine concentrations to the brain and other organs within 10 s of inhalation. Nicotine's acute effects dissipate in a few minutes, encouraging the smoker to smoke frequently throughout the day to maintain its pleasurable effects and prevent withdrawal symptoms. Nicotine and other constituents of smoke also provide sensory stimuli which, through repeated pairings, become conditioned reinforcers and further strengthen tobacco self-administration, creating an extremely persistant behavior. Nicotine replacement medications provide relief of cigarette withdrawal symptoms and are effective aids in smoking cessation; however, sustaining long-term abstinence can still be very difficult.