Zyban Information
Zyban () Warning
Serious neuropsychiatric events, including but not limited to depression, suicidal ideation, suicide attempt, and completed suicide have been reported in patients taking Zyban () for smoking cessation. Some cases may have been complicated by the symptoms of nicotine withdrawal in patients who stopped smoking. Depressed mood may be a symptom of nicotine withdrawal. Depression, rarely including suicidal ideation, has been reported in smokers undergoing a smoking cessation attempt without medication. However, some of these symptoms have occurred in patients taking Zyban () who continued to smoke.
All patients being treated with Zyban () should be observed for neuropsychiatric symptoms including changes in behavior, hostility, agitation, depressed mood, and suicide-related events, including ideation, behavior, and attempted suicide. These symptoms, as well as worsening of pre-existing psychiatric illness and completed suicide have been reported in some patients attempting to quit smoking while taking Zyban () in the postmarketing experience. When symptoms were reported, most were during treatment with Zyban () , but some were following discontinuation of treatment with Zyban () . These events have occurred in patients with and without pre-existing psychiatric disease; some have experienced worsening of their psychiatric illnesses. Patients with serious psychiatric illness such as schizophrenia, bipolar disorder, and major depressive disorder did not participate in the premarketing studies of Zyban () .
The risks of Zyban () should be weighed against the benefits of its use. Zyban () has been demonstrated to increase the likelihood of abstinence from smoking for as long as 6 months compared to treatment with placebo. The health benefits of quitting smoking are immediate and substantial. (See WARNINGS: Neuropsychiatric Symptoms and Suicide Risk in Smoking Cessation Treatment and PRECAUTIONS: Information for Patients.)
Although Zyban () is not indicated for treatment of depression, it contains the same active ingredient as the antidepressant medications WELLBUTRIN, WELLBUTRIN SR , and WELLBUTRIN XL. Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of major depressive disorder (MDD) and other psychiatric disorders. Anyone considering the use of Zyban () or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber. Zyban () is not approved for use in pediatric patients. (See WARNINGS: Clinical Worsening and Suicide Risk in Treating Psychiatric Disorders, PRECAUTIONS: Information for Patients, and PRECAUTIONS: Pediatric Use.)
Zyban () Description
Zyban () (bupropion hydrochloride) Sustained-Release Tablets are a non-nicotine aid to smoking cessation. Zyban () is chemically unrelated to nicotine or other agents currently used in the treatment of nicotine addiction. Initially developed and marketed as an antidepressant (WELLBUTRIN [bupropion hydrochloride] Tablets and WELLBUTRIN SR [bupropion hydrochloride] Sustained-Release Tablets), Zyban () is also chemically unrelated to tricyclic, tetracyclic, selective serotonin re-uptake inhibitor, or other known antidepressant agents. Its structure closely resembles that of diethylpropion; it is related to phenylethylamines. It is (±)-1-(3-chlorophenyl)-2-[(1,1-dimethylethyl)amino]-1-propanone hydrochloride. The molecular weight is 276.2. The molecular formula is CHClNO•HCl. Bupropion hydrochloride powder is white, crystalline, and highly soluble in water. It has a bitter taste and produces the sensation of local anesthesia on the oral mucosa. The structural formula is:
Zyban () is supplied for oral administration as 150-mg (purple), film-coated, sustained-release tablets. Each tablet contains the labeled amount of bupropion hydrochloride and the inactive ingredients carnauba wax, cysteine hydrochloride, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80 and titanium dioxide and is printed with edible black ink. In addition, the 150-mg tablet contains FD&C Blue No. 2 Lake and FD&C Red No. 40 Lake.
Zyban () Clinical Pharmacology
Bupropion is a racemic mixture. The pharmacologic activity and pharmacokinetics of the individual enantiomers have not been studied. Bupropion follows biphasic pharmacokinetics best described by a 2-compartment model. The terminal phase has a mean half-life (±% CV) of about 21 hours (±20%), while the distribution phase has a mean half-life of 3 to 4 hours.
Following oral administration of Zyban () to healthy volunteers, peak plasma concentrations of bupropion are achieved within 3 hours. The mean peak concentration (C) values were 91 and 143 ng/mL from 2 single-dose (150-mg) studies. At steady state, the mean C following a 150-mg dose every 12 hours is 136 ng/mL.
Exposure to bupropion may be increased when Zyban () tablets are taken with food. Three studies in healthy volunteers demonstrated peak plasma concentrations (C) of bupropion increased by 11% to 35% when administered with food, while overall exposure (AUC) to bupropion increased by 16% to 19%. The food effect is not considered clinically significant and Zyban () can be taken with or without food.
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Because bupropion is extensively metabolized, there is the potential for drug-drug interactions, particularly with those agents that are metabolized by or which inhibit/induce the cytochrome P450IIB6 (CYP2B6) isoenzyme, such as ritonavir or efavirenz. In a healthy volunteer study, ritonavir at a dose of 100 mg twice daily reduced the AUC and C of bupropion by 22% and 21%, respectively. The exposure of the hydroxybupropion metabolite was decreased by 23%, the threohydrobupropion decreased by 38%, and the erythrohydrobupropion decreased by 48%.
In a second healthy volunteer study, ritonavir at a dose of 600 mg twice daily decreased the AUC and the C of bupropion by 66% and 62%, respectively. The exposure of the hydroxybupropion metabolite was decreased by 78%, the threohydrobupropion decreased by 50%, and the erythrohydrobupropion decreased by 68%.
In another healthy volunteer study, KALETRA (lopinavir 400 mg/ritonavir 100 mg twice daily) decreased bupropion AUC and C by 57%. The AUC and C of hydroxybupropion were decreased by 50% and 31%, respectively (see PRECAUTIONS: Drug Interactions).
In a study in healthy volunteers, efavirenz 600 mg once daily for 2 weeks reduced the AUC and Cof bupropion by approximately 55% and 34%, respectively. The AUC of hydroxybupropion was unchanged, whereas Cof hydroxybupropion was increased by 50%.
Although bupropion is not metabolized by cytochrome P450IID6 (CYP2D6), there is the potential for drug-drug interactions when bupropion is coadministered with drugs metabolized by this isoenzyme (see PRECAUTIONS: Drug Interactions).
Following a single dose in humans, peak plasma concentrations of hydroxybupropion occur approximately 6 hours after administration of Zyban () . Peak plasma concentrations of hydroxybupropion are approximately 10 times the peak level of the parent drug at steady state. The elimination half-life of hydroxybupropion is approximately 20 (±5) hours and its AUC at steady state is about 17 times that of bupropion. The times to peak concentrations for the erythrohydrobupropion and threohydrobupropion metabolites are similar to that of the hydroxybupropion metabolite; however, their elimination half-lives are longer, 33 (±10) and 37 (±13) hours, respectively, and steady-state AUCs are 1.5 and 7 times that of bupropion, respectively.
Bupropion and its metabolites exhibit linear kinetics following chronic administration of 300 to 450 mg/day.
Following oral administration of 200 mg of C-bupropion in humans, 87% and 10% of the radioactive dose were recovered in the urine and feces, respectively. The fraction of the oral dose of bupropion excreted unchanged was only 0.5%.
The effects of cigarette smoking on the pharmacokinetics of bupropion were studied in 34 healthy male and female volunteers; 17 were chronic cigarette smokers and 17 were nonsmokers. Following oral administration of a single 150-mg dose of Zyban () , there was no statistically significant difference in C, half-life, T, AUC, or clearance of bupropion or its major metabolites between smokers and nonsmokers.
In a study comparing the treatment combination of Zyban () and nicotine transdermal system (NTS) versus Zyban () alone, no statistically significant differences were observed between the 2 treatment groups of combination Zyban () and NTS (n = 197) and Zyban () alone (n = 193) in the plasma concentrations of bupropion or its active metabolites at weeks 3 and 6.
Factors or conditions altering metabolic capacity (e.g., liver disease, congestive heart failure [CHF], age, concomitant medications, etc.) or elimination may be expected to influence the degree and extent of accumulation of the active metabolites of bupropion. The elimination of the major metabolites of bupropion may be affected by reduced renal or hepatic function because they are moderately polar compounds and are likely to undergo further metabolism or conjugation in the liver prior to urinary excretion.
The second study showed that there were no statistically significant differences in the pharmacokinetics of bupropion and its active metabolites in 9 patients with mild-to-moderate hepatic cirrhosis compared to 8 healthy volunteers. However, more variability was observed in some of the pharmacokinetic parameters for bupropion (AUC, C, and T) and its active metabolites (t) in patients with mild-to-moderate hepatic cirrhosis. In addition, in patients with severe hepatic cirrhosis, the bupropion C and AUC were substantially increased (mean difference: by approximately 70% and 3-fold, respectively) and more variable when compared to values in healthy volunteers; the mean bupropion half-life was also longer (29 hours in patients with severe hepatic cirrhosis vs. 19 hours in healthy subjects). For the metabolite hydroxybupropion, the mean C was approximately 69% lower. For the combined amino-alcohol isomers threohydrobupropion and erythrohydrobupropion, the mean C was approximately 31% lower. The mean AUC increased by 28% for hydroxybupropion and 50% for threo/erythrohydrobupropion. The median T was observed 19 hours later for hydroxybupropion and 21 hours later for threo/erythrohydrobupropion. The mean half-lives for hydroxybupropion and threo/erythrohydrobupropion were increased 2- and 4-fold, respectively, in patients with severe hepatic cirrhosis compared to healthy volunteers (see WARNINGS, PRECAUTIONS, and DOSAGE AND ADMINISTRATION).
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Zyban () Clinical Trials
The efficacy of Zyban () as an aid to smoking cessation was demonstrated in 3 placebo-controlled, double-blind trials in nondepressed chronic cigarette smokers (n = 1,940, ≥15 cigarettes per day). In these studies, Zyban () was used in conjunction with individual smoking cessation counseling.
The first study was a dose-response trial conducted at 3 clinical centers. Patients in this study were treated for 7 weeks with 1 of 3 doses of Zyban () (100, 150, or 300 mg/day) or placebo; quitting was defined as total abstinence during the last 4 weeks of treatment (weeks 4 through 7). Abstinence was determined by patient daily diaries and verified by carbon monoxide levels in expired air.
Results of this dose-response trial with Zyban () demonstrated a dose-dependent increase in the percentage of patients able to achieve 4-week abstinence (weeks 4 through 7). Treatment with Zyban () at both 150 and 300 mg/day was significantly more effective than placebo in this study.
Table 1 presents quit rates over time in the multicenter trial by treatment group. The quit rates are the proportions of all persons initially enrolled (i.e., intent-to-treat analysis) who abstained from week 4 of the study through the specified week. Treatment with Zyban () (150 or 300 mg/day) was more effective than placebo in helping patients achieve 4-week abstinence. In addition, treatment with Zyban () (7 weeks at 300 mg/day) was more effective than placebo in helping patients maintain continuous abstinence through week 26 (6 months) of the study.
The second study was a comparative trial conducted at 4 clinical centers. Four treatments were evaluated: Zyban () 300 mg/day, nicotine transdermal system (NTS) 21 mg/day, combination of Zyban () 300 mg/day plus NTS 21 mg/day, and placebo. Patients were treated for 9 weeks. Treatment with Zyban () was initiated at 150 mg/day while the patient was still smoking and was increased after 3 days to 300 mg/day given as 150 mg twice daily. NTS 21 mg/day was added to treatment with Zyban () after approximately 1 week when the patient reached the target quit date. During weeks 8 and 9 of the study, NTS was tapered to 14 and 7 mg/day, respectively. Quitting, defined as total abstinence during weeks 4 through 7, was determined by patient daily diaries and verified by expired air carbon monoxide levels. In this study, patients treated with any of the 3 treatments achieved greater 4-week abstinence rates than patients treated with placebo.
Table 2 presents quit rates over time by treatment group for the comparative trial.
When patients in this study were followed out to one year, the superiority of Zyban () and the combination of Zyban () and NTS over placebo in helping patients to achieve abstinence from smoking was maintained. The continuous abstinence rate was 30% (95% CI 24-35) in the patients treated with Zyban () , and 33% (95% CI 27-39) for patients treated with the combination at 26 weeks compared with 13% (95% CI 7-18) in the placebo group. At 52 weeks, the continuous abstinence rate was 23% (95% CI 18-28) in the patients treated with Zyban () , and 28% (95% CI 23-34) for patients treated with the combination, compared with 8% (95% CI 3-12) in the placebo group. Although the treatment combination of Zyban () and NTS displayed the highest rates of continuous abstinence throughout the study, the quit rates for the combination were not significantly higher (>0.05) than for Zyban () alone.
The comparisons between Zyban () , NTS, and combination treatment in this study have not been replicated, and, therefore should not be interpreted as demonstrating the superiority of any of the active treatment arms over any other.
The third study was a long-term maintenance trial conducted at 5 clinical centers. Patients in this study received open-label Zyban () 300 mg/day for 7 weeks. Patients who quit smoking while receiving Zyban () (n = 432) were then randomized to Zyban () 300 mg/day or placebo for a total study duration of 1 year. Abstinence from smoking was determined by patient self-report and verified by expired air carbon monoxide levels. This trial demonstrated that at 6 months, continuous abstinence rates were significantly higher for patients continuing to receive Zyban () than for those switched to placebo (
Quit rates in clinical trials are influenced by the population selected. Quit rates in an unselected population may be lower than the above rates. Quit rates for Zyban () were similar in patients with and without prior quit attempts using nicotine replacement therapy.
Treatment with Zyban () reduced withdrawal symptoms compared to placebo. Reductions on the following withdrawal symptoms were most pronounced: irritability, frustration, or anger; anxiety; difficulty concentrating; restlessness; and depressed mood or negative affect. Depending on the study and the measure used, treatment with Zyban () showed evidence of reduction in craving for cigarettes or urge to smoke compared to placebo.
Zyban () Indications And Usage
Zyban () is indicated as an aid to smoking cessation treatment.
Zyban () Contraindications
Zyban () is contraindicated in patients with a seizure disorder.
Zyban () is contraindicated in patients treated with WELLBUTRIN (bupropion hydrochloride), the immediate-release formulation; WELLBUTRIN SR (bupropion hydrochloride), the sustained-release formulation; WELLBUTRIN XL (bupropion hydrochloride), the extended-release formulation; or any other medications that contain bupropion because the incidence of seizure is dose dependent.
Zyban () is contraindicated in patients with a current or prior diagnosis of bulimia or anorexia nervosa because of a higher incidence of seizures noted in patients treated for bulimia with the immediate-release formulation of bupropion.
Zyban () is contraindicated in patients undergoing abrupt discontinuation of alcohol or sedatives (including benzodiazepines).
The concurrent administration of Zyban () and a monoamine oxidase (MAO) inhibitor is contraindicated. At least 14 days should elapse between discontinuation of an MAO inhibitor and initiation of treatment with Zyban () .
Zyban () is contraindicated in patients who have shown an allergic response to bupropion or the other ingredients that make up Zyban () .
Zyban () Warnings
Serious neuropsychiatric symptoms have been reported in patients taking Zyban () for smoking cessation Some reported cases may have been complicated by the symptoms of nicotine withdrawal in patients who stopped smoking. Depressed mood may be a symptom of nicotine withdrawal. Depression, rarely including suicidal ideation, has been reported in smokers undergoing a smoking cessation attempt without medication. However, some of these symptoms have occurred in patients taking Zyban () who continued to smoke. When symptoms were reported, most were during treatment with Zyban () , but some were following discontinuation of treatment with Zyban () .
These events have occurred in patients with and without pre-existing psychiatric disease; some patients have experienced worsening of their psychiatric illnesses. All patients being treated with Zyban () should be observed for neuropsychiatric symptoms or worsening of pre-existing psychiatric illness.
Patients with serious psychiatric illness such as schizophrenia, bipolar disorder, and major depressive disorder did not participate in the premarketing studies of Zyban () .
Advise patients and caregivers that the patient should stop taking Zyban () and contact a healthcare provider immediately if agitation, depressed mood, or changes in behavior or thinking that are not typical for the patient are observed, or if the patient develops suicidal ideation or suicidal behavior. In many postmarketing cases, resolution of symptoms after discontinuation of Zyban () was reported, although in some cases the symptoms persisted, therefore, ongoing monitoring and supportive care should be provided until symptoms resolve.
The risks of Zyban () should be weighed against the benefits of its use. Zyban () has been demonstrated to increase the likelihood of abstinence from smoking for as long as six months compared to treatment with placebo. The health benefits of quitting smoking are immediate and substantial.
Patients with major depressive disorder (MDD), both adult and pediatric, may experience worsening of their depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior, whether or not they are taking antidepressant medications, and this risk may persist until significant remission occurs. Suicide is a known risk of depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide. There has been a long-standing concern, however, that antidepressants may have a role in inducing worsening of depression and the emergence of suicidality in certain patients during the early phases of treatment. Pooled analyses of short-term placebo-controlled trials of antidepressant drugs (SSRIs and others) showed that these drugs increase the risk of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults (ages 18-24) with major depressive disorder (MDD) and other psychiatric disorders. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction with antidepressants compared to placebo in adults aged 65 and older.
The pooled analyses of placebo-controlled trials in children and adolescents with MDD, obsessive compulsive disorder (OCD), or other psychiatric disorders included a total of 24 short-term trials of 9 antidepressant drugs in over 4,400 patients. The pooled analyses of placebo-controlled trials in adults with MDD or other psychiatric disorders included a total of 295 short-term trials (median duration of 2 months) of 11 antidepressant drugs in over 77,000 patients. There was considerable variation in risk of suicidality among drugs, but a tendency toward an increase in the younger patients for almost all drugs studied. There were differences in absolute risk of suicidality across the different indications, with the highest incidence in MDD. The risk differences (drug vs. placebo), however, were relatively stable within age strata and across indications. These risk differences (drug-placebo difference in the number of cases of suicidality per 1,000 patients treated) are provided in Table 4.
No suicides occurred in any of the pediatric trials. There were suicides in the adult trials, but the number was not sufficient to reach any conclusion about drug effect on suicide.
It is unknown whether the suicidality risk extends to longer-term use, i.e., beyond several months. However, there is substantial evidence from placebo-controlled maintenance trials in adults with depression that the use of antidepressants can delay the recurrence of depression.
All patients being treated with antidepressants for any indication should be monitored appropriately and observed closely for clinical worsening, suicidality, and unusual changes in behavior, especially during the initial few months of a course of drug therapy, or at times of dose changes, either increases or decreases.
The following symptoms, anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, and mania, have been reported in adult and pediatric patients being treated with antidepressants for major depressive disorder as well as for other indications, both psychiatric and nonpsychiatric. Although a causal link between the emergence of such symptoms and either the worsening of depression and/or the emergence of suicidal impulses has not been established, there is concern that such symptoms may represent precursors to emerging suicidality.
Consideration should be given to changing the therapeutic regimen, including possibly discontinuing the medication, in patients whose depression is persistently worse, or who are experiencing emergent suicidality or symptoms that might be precursors to worsening depression or suicidality, especially if these symptoms are severe, abrupt in onset, or were not part of the patient's presenting symptoms.
Families and caregivers of patients being treated with antidepressants for major depressive disorder or other indications, both psychiatric and nonpsychiatric, should be alerted about the need to monitor patients for the emergence of agitation, irritability, unusual changes in behavior, and the other symptoms described above, as well as the emergence of suicidality, and to report such symptoms immediately to healthcare providers. Such monitoring should include daily observation by families and caregivers.
Because the use of bupropion is associated with a dose-dependent risk of seizures, The risk of seizures is also related to patient factors, clinical situation, and concomitant medications, which must be considered in selection of patients for therapy with Zyban () . Zyban () should be discontinued and not restarted in patients who experience a seizure while on treatment.
Data for the immediate-release formulation of bupropion revealed a seizure incidence of approximately 0.4% (4/1,000) in depressed patients treated at doses in a range of 300 to 450 mg/day. In addition, the estimated seizure incidence increases almost tenfold between 450 and 600 mg/day.
Zyban () should be administered with extreme caution to patients with a history of seizure, cranial trauma, or other predisposition(s) toward seizure, or patients treated with other agents (e.g., antipsychotics, antidepressants, theophylline, systemic steroids, etc.) that lower seizure threshold.
Zyban () should be used with extreme caution in patients with severe hepatic cirrhosis. In these patients a reduced frequency of dosing is required, as peak bupropion levels are substantially increased and accumulation is likely to occur in such patients to a greater extent than usual. The dose should not exceed 150 mg every other day in these patients (see CLINICAL PHARMACOLOGY, PRECAUTIONS, and DOSAGE AND ADMINISTRATION).
Zyban () Precautions
Arthralgia, myalgia, and fever with rash and other symptoms suggestive of delayed hypersensitivity have been reported in association with bupropion. These symptoms may resemble serum sickness.
In the comparative trial, 40% of the patients treated with 300 mg/day of Zyban () , 28% of the patients treated with 21 mg/day of NTS, and 45% of the patients treated with the combination of Zyban () and NTS experienced insomnia compared to 18% of placebo-treated patients. Symptoms were sufficiently severe to require discontinuation of treatment in 0.8% of patients treated with Zyban () and none of the patients in the other 3 treatment groups.
Insomnia may be minimized by avoiding bedtime doses and, if necessary, reduction in dose.
Data from a comparative study of Zyban () , nicotine transdermal system (NTS), the combination of sustained-release bupropion plus NTS, and placebo as an aid to smoking cessation suggest a higher incidence of treatment-emergent hypertension in patients treated with the combination of Zyban () and NTS. In this study, 6.1% of patients treated with the combination of Zyban () and NTS had treatment-emergent hypertension compared to 2.5%, 1.6%, and 3.1% of patients treated with Zyban () , NTS, and placebo, respectively. The majority of these patients had evidence of preexisting hypertension. Three patients (1.2%) treated with the combination of Zyban () and NTS and 1 patient (0.4%) treated with NTS had study medication discontinued due to hypertension compared to none of the patients treated with Zyban () or placebo. Monitoring of blood pressure is recommended in patients who receive the combination of bupropion and nicotine replacement.
There is no clinical experience establishing the safety of Zyban () in patients with a recent history of myocardial infarction or unstable heart disease. Therefore, care should be exercised if it is used in these groups. Bupropion was well tolerated in depressed patients who had previously developed orthostatic hypotension while receiving tricyclic antidepressants, and was also generally well tolerated in a group of 36 depressed inpatients with stable congestive heart failure (CHF). However, bupropion was associated with a rise in supine blood pressure in the study of patients with CHF, resulting in discontinuation of treatment in 2 patients for exacerbation of baseline hypertension.
All patients with hepatic impairment should be closely monitored for possible adverse effects that could indicate high drug and metabolite levels (see CLINICAL PHARMACOLOGY, WARNINGS, and DOSAGE AND ADMINISTRATION).
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Although Zyban () is not indicated for treatment of depression, it contains the same active ingredient as the antidepressant medications WELLBUTRIN, WELLBUTRIN SR, and WELLBUTRIN XL. Prescribers or other health professionals should inform patients, their families, and their caregivers about the benefits and risks associated with treatment with Zyban () and should counsel them in its appropriate use. A patient Medication Guide about “Quitting Smoking, Quit-Smoking Medication, Changes in Thinking and Behavior, Depression, and Suicidal Thoughts or Actions,” “Antidepressant Medicines, Depression and Other Serious Mental Illnesses, and Suicidal Thoughts or Actions,” and “What Other Important Information Should I Know About Zyban () ?” is available for Zyban () . The prescriber or health professional should instruct patients, their families, and their caregivers to read the Medication Guide and should assist them in understanding its contents. Patients should be given the opportunity to discuss the contents of the Medication Guide and to obtain answers to any questions they may have. The complete text of the Medication Guide is reprinted at the end of this document.
Patients should be advised of the following issues and asked to alert their prescriber if these occur while taking Zyban () .
In vitro studies indicate that bupropion is primarily metabolized to hydroxybupropion by the CYP2B6 isoenzyme. Therefore, the potential exists for a drug interaction between Zyban () and drugs that are substrates of or inhibitors/inducers of the CYP2B6 isoenzyme (e.g., orphenadrine, thiotepa, cyclophosphamide, ticlopidine, and clopidogrel). In addition, in vitro studies suggest that paroxetine, sertraline, norfluoxetine, and fluvoxamine as well as nelfinavir inhibit the hydroxylation of bupropion. No clinical studies have been performed to evaluate this finding. The threohydrobupropion metabolite of bupropion does not appear to be produced by the cytochrome P450 isoenzymes.
In a series of studies in healthy volunteers, ritonavir (100 mg twice daily or 600 mg twice daily) or ritonavir 100 mg plus lopinavir 400 mg (KALETRA) twice daily reduced the exposure of bupropion and its major metabolites in a dose dependent manner by approximately 20% to 80%. Similarly, efavirenz 600 mg once daily for 2 weeks reduced the exposure of bupropion by approximately 55%. This effect of ritonavir, KALETRA, and efavirenz is thought to be due to the induction of bupropion metabolism. Patients receiving of these drugs with bupropion may need increased doses of bupropion, but the maximum recommended dose of bupropion should not be exceeded (see CLINICAL PHARMACOLOGY: Metabolism).
Multiple oral doses of bupropion had no statistically significant effects on the single dose pharmacokinetics of lamotrigine in 12 healthy volunteers.
Animal data indicated that bupropion may be an inducer of drug-metabolizing enzymes in humans. However, following chronic administration of bupropion, 100 mg three times daily to 8 healthy male volunteers for 14 days, there was no evidence of induction of its own metabolism. Because bupropion is extensively metabolized, the coadministration of other drugs may affect its clinical activity. In particular, certain drugs may induce the metabolism of bupropion (e.g., carbamazepine, phenobarbital, phenytoin), while other drugs may inhibit the metabolism of bupropion (e.g., cimetidine). The effects of concomitant administration of cimetidine on the pharmacokinetics of bupropion and its active metabolites were studied in 24 healthy young male volunteers. Following oral administration of two 150-mg Zyban () tablets with and without 800 mg of cimetidine, the pharmacokinetics of bupropion and its hydroxy metabolite were unaffected. However, there were 16% and 32% increases, respectively, in the AUC and C of the combined moieties of threohydro- and erythrohydro- bupropion.
Therefore, coadministration of bupropion with drugs that are metabolized by CYP2D6 isoenzyme including certain antidepressants (e.g., nortriptyline, imipramine, desipramine, paroxetine, fluoxetine, sertraline), antipsychotics (e.g., haloperidol, risperidone, thioridazine), beta-blockers (e.g., metoprolol), and Type 1C antiarrhythmics (e.g., propafenone, flecainide), should be approached with caution and should be initiated at the lower end of the dose range of the concomitant medication. If bupropion is added to the treatment regimen of a patient already receiving a drug metabolized by CYP2D6, the need to decrease the dose of the original medication should be considered, particularly for those concomitant medications with a narrow therapeutic index.
Drugs which require metabolic activation by CYP2D6 in order to be effective (e.g., tamoxifen) theoretically could have reduced efficacy when administered concomitantly with inhibitors of CYP2D6 such as bupropion.
Although citalopram is not primarily metabolized by CYP2D6, in one study bupropion increased the C and AUC of citalopram by 30% and 40%, respectively. Citalopram did not affect the pharmacokinetics of bupropion and its three metabolites.
Lifetime carcinogenicity studies were performed in rats and mice at doses up to 300 and 150 mg/kg/day, respectively. These doses are approximately 10 and 2 times the maximum recommended human dose (MRHD), respectively, on a mg/m basis. In the rat study, there was an increase in nodular proliferative lesions of the liver at doses of 100 to 300 mg/kg/day (approximately 3 to 10 times the MRHD on a mg/m basis); lower doses were not tested. The question of whether or not such lesions may be precursors of neoplasms of the liver is currently unresolved. Similar liver lesions were not seen in the mouse study, and no increase in malignant tumors of the liver and other organs was seen in either study.
Bupropion produced a positive response (2 to 3 times control mutation rate) in 2 of 5 strains in the Ames bacterial mutagenicity test and an increase in chromosomal aberrations in 1 of 3 in vivo rat bone marrow cytogenic studies.
A fertility study in rats at doses up to 300 mg/kg revealed no evidence of impaired fertility.
When rats were administered bupropion at oral doses of up to 300 mg/kg/day (approximately 10 times the MRHD on a mg/m basis) prior to mating and throughout pregnancy and lactation, there were no apparent adverse effects on offspring development.
One study has been conducted in pregnant women. This retrospective, managed-care database study assessed the risk of congenital malformations overall and cardiovascular malformations specifically, following exposure to bupropion in the first trimester compared to the risk of these malformations following exposure to other antidepressants in the first trimester and bupropion outside of the first trimester. This study included 7,005 infants with antidepressant exposure during pregnancy, 1,213 of whom were exposed to bupropion in the first trimester. The study showed no greater risk for congenital malformations overall or cardiovascular malformations specifically, following first trimester bupropion exposure compared to exposure to all other antidepressants in the first trimester, or bupropion outside of the first trimester. The results of this study have not been corroborated. Zyban () should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Pregnant smokers should be encouraged to attempt cessation using educational and behavioral interventions before pharmacological approaches are used.
Of the approximately 6,000 patients who participated in clinical trials with bupropion sustained-release tablets (depression and smoking cessation studies), 275 were 65 and over and 47 were 75 and over. In addition, several hundred patients 65 and over participated in clinical trials using the immediate-release formulation of bupropion (depression studies). No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
A single-dose pharmacokinetic study demonstrated that the disposition of bupropion and its metabolites in elderly subjects was similar to that of younger subjects; however, another pharmacokinetic study, single and multiple dose, has suggested that the elderly are at increased risk for accumulation of bupropion and its metabolites (see CLINICAL PHARMACOLOGY).
Bupropion is extensively metabolized in the liver to active metabolites, which are further metabolized and excreted by the kidneys. The risk of toxic reaction to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function (see PRECAUTIONS: Renal Impairment and DOSAGE AND ADMINISTRATION).
Zyban () Adverse Reactions (see Also Warnings And Precautions.)
The information included under ADVERSE REACTIONS is based primarily on data from the dose-response trial and the comparative trial that evaluated Zyban () for smoking cessation (see CLINICAL TRIALS). Information on additional adverse events associated with the sustained-release formulation of bupropion in depression trials, as well as the immediate-release formulation of bupropion, is included in a separate section (see Other Events Observed During the Clinical Development and Postmarketing Experience of Bupropion).
Table 5 enumerates selected treatment-emergent adverse events from the dose-response trial that occurred at an incidence of 1% or more and were more common in patients treated with Zyban () compared to those treated with placebo. Table 6 enumerates selected treatment-emergent adverse events from the comparative trial that occurred at an incidence of 1% or more and were more common in patients treated with Zyban () , NTS, or the combination of Zyban () and NTS compared to those treated with placebo. Reported adverse events were classified using a COSTART-based dictionary.
a
a
b
Zyban () was well tolerated in the long-term maintenance trial that evaluated chronic administration of Zyban () for up to 1 year and in the COPD trial that evaluated patients with mild-to-moderate COPD for a 12-week period. Adverse events in both studies were quantitatively and qualitatively similar to those observed in the dose-response and comparative trials.
In addition to the adverse events noted above, the following events have been reported in clinical trials and postmarketing experience with the sustained-release formulation of bupropion in depressed patients and in nondepressed smokers, as well as in clinical trials and postmarketing clinical experience with the immediate-release formulation of bupropion.
Adverse events for which frequencies are provided below occurred in clinical trials with the sustained-release formulation of bupropion . The frequencies represent the proportion of patients who experienced a treatment-emergent adverse event on at least one occasion in placebo-controlled studies for depression (n = 987) or smoking cessation (n = 1,013), or patients who experienced an adverse event requiring discontinuation of treatment in an open-label surveillance study with bupropion sustained-release tablets (n = 3,100). All treatment-emergent adverse events are included except those listed in Tables 5 and 6, those events listed in other safety-related sections of the insert, those adverse events subsumed under COSTART terms that are either overly general or excessively specified so as to be uninformative, those events not reasonably associated with the use of the drug, and those events that were not serious and occurred in fewer than 2 patients.
Events are further categorized by body system and listed in order of decreasing frequency according to the following definitions of frequency: Frequent adverse events are defined as those occurring in at least 1/100 patients. Infrequent adverse events are those occurring in 1/100 to 1/1,000 patients, while rare events are those occurring in less than 1/1,000 patients.
Adverse events for which frequencies are not provided occurred in clinical trials or postmarketing experience with bupropion. Only those adverse events not previously listed for sustained-release bupropion are included. The extent to which these events may be associated with Zyban () is unknown.
Zyban () Drug Abuse And Dependence
Zyban () is likely to have a low abuse potential.
Studies in rodents and primates have shown that bupropion exhibits some pharmacologic actions common to psychostimulants. In rodents, it has been shown to increase locomotor activity, elicit a mild stereotyped behavioral response, and increase rates of responding in several schedule-controlled behavior paradigms. In primate models to assess the positive reinforcing effects of psychoactive drugs, bupropion was self-administered intravenously. In rats, bupropion produced amphetamine- and cocaine-like discriminative stimulus effects in drug discrimination paradigms used to characterize the subjective effects of psychoactive drugs.
The possibility that bupropion may induce dependence should be kept in mind when evaluating the desirability of including the drug in smoking cessation programs of individual patients.
Zyban () Overdosage
Overdoses of up to 30 g or more of bupropion have been reported. Seizure was reported in approximately one-third of all cases. Other serious reactions reported with overdoses of bupropion alone included hallucinations, loss of consciousness, sinus tachycardia, and ECG changes such as conduction disturbances (including QRS prolongation) or arrhythmias. Fever, muscle rigidity, rhabdomyolysis, hypotension, stupor, coma, and respiratory failure have been reported mainly when bupropion was part of multiple drug overdoses.
Although most patients recovered without sequelae, deaths associated with overdoses of bupropion alone have been reported in patients ingesting large doses of the drug. Multiple uncontrolled seizures, bradycardia, cardiac failure, and cardiac arrest prior to death were reported in these patients.
Ensure an adequate airway, oxygenation, and ventilation. Monitor cardiac rhythm and vital signs. EEG monitoring is also recommended for the first 48 hours post-ingestion. General supportive and symptomatic measures are also recommended. Induction of emesis is not recommended.
Activated charcoal should be administered. There is no experience with the use of forced diuresis, dialysis, hemoperfusion, or exchange transfusion in the management of bupropion overdoses. No specific antidotes for bupropion are known.
Due to the dose-related risk of seizures with Zyban () , hospitalization following suspected overdose should be considered. Based on studies in animals, it is recommended that seizures be treated with intravenous benzodiazepine administration and other supportive measures, as appropriate.
In managing overdosage, consider the possibility of multiple drug involvement. The physician should consider contacting a poison control center for additional information on the treatment of any overdose. Telephone numbers for certified poison control centers are listed in the (PDR).
Zyban () Dosage And Administration
Patients are more likely to quit smoking and remain abstinent if they are seen frequently and receive support from their physicians or other healthcare professionals. It is important to ensure that patients read the instructions provided to them and have their questions answered. Physicians should review the patient’s overall smoking cessation program that includes treatment with Zyban () . Patients should be advised of the importance of participating in the behavioral interventions, counseling, and/or support services to be used in conjunction with Zyban () . See Medication Guide at the end of the prescribing information.
The goal of therapy with Zyban () is complete abstinence. If a patient has not made significant progress towards abstinence by the seventh week of therapy with Zyban () , it is unlikely that he or she will quit during that attempt, and treatment should probably be discontinued.
Patients who fail to quit smoking during an attempt may benefit from interventions to improve their chances for success on subsequent attempts. Patients who are unsuccessful should be evaluated to determine why they failed. A new quit attempt should be encouraged when factors that contributed to failure can be eliminated or reduced, and conditions are more favorable.
Zyban () How Supplied
Zyban () Sustained-Release Tablets, 150 mg of bupropion hydrochloride, are purple, round, biconvex, film-coated tablets printed with “Zyban () 150” in bottles of 60 (NDC 0173-0556-02) tablets and the Zyban () Advantage Pack containing 1 bottle of 60 (NDC 0173-0556-01) tablets.
Zyban () , WELLBUTRIN, WELLBUTRIN SR, WELLBUTRIN XL are registered trademarks of GlaxoSmithKline.KALETRA is a registered trademark of Abbott Laboratories.
Distributed by:
GlaxoSmithKline
Research Triangle Park, NC 27709
Manufactured by:
GlaxoSmithKline
Research Triangle Park
or DSM Pharmaceuticals, Inc.
Greenville, NC 27834
©2010, GlaxoSmithKline. All rights reserved.
August 2011
ZYB:6PI
Zyban () Medication Guide
Read this Medication Guide carefully before you start using Zyban () and each time you get a refill. There may be new information. This information does not take the place of talking with your doctor about your medical condition or your treatment. If you have any questions about Zyban () , ask your doctor or pharmacist.
This section of the Medication Guide is only about the risk of changes in thinking and behavior depression and suicidal thoughts or actions with drugs used to quit smoking.
Some people have had changes in behavior, hostility, agitation, depression, suicidal thoughts or actions while taking Zyban () to help them quit smoking. These symptoms can develop during treatment with Zyban () or after stopping treatment with Zyban () .
If you, your family member, or your caregiver notice agitation, hostility, depression, or changes in thinking or behavior that are not typical for you, or you have any of the following symptoms, stop taking Zyban () and call your healthcare provider right away:
When you try to quit smoking, with or without Zyban () , you may have symptoms that may be due to nicotine withdrawal, including urge to smoke, depressed mood, trouble sleeping, irritability, frustration, anger, feeling anxious, difficulty concentrating, restlessness, decreased heart rate, and increased appetite or weight gain. Some people have even experienced suicidal thoughts when trying to quit smoking without medication. Sometimes quitting smoking can lead to worsening of mental health problems that you already have, such as depression.
Before taking Zyban () , tell your healthcare provider if you have ever had depression or other mental health problems. You should also tell your doctor about any symptoms you had during other times you tried to quit smoking, with or without Zyban () .
Although Zyban () is not a treatment for depression, it contains bupropion, the same active ingredient as the antidepressant medications WELLBUTRIN, WELLBUTRIN SR, and WELLBUTRIN XL.
This section of the Medication Guide is only about the risk of suicidal thoughts and actions with antidepressant medicines.
Zyban () has not been studied in children under the age of 18 and is not approved for use in children and teenagers.
The chance of having seizures increases with higher doses of Zyban () . For more information, see the sections “Who should not take Zyban () ?” and “What should I tell my doctor before using Zyban () ?” Tell your doctor about all of your medical conditions and all the medicines you take.
Zyban () is a prescription medicine to help people quit smoking. Studies have shown that more than one third of people quit smoking for at least 1 month while taking Zyban () and participating in a patient support program. For many patients, Zyban () reduces withdrawal symptoms and the urge to smoke. Zyban () should be used with a patient support program. It is important to participate in the behavioral program, counseling, or other support program your healthcare professional recommends.
Tell your doctor if you have ever had depression, suicidal thoughts or actions, or other mental health problems. You should also tell your doctor about any symptoms you had during other times you tried to quit smoking, with or without Zyban () . See “Quitting Smoking, Quit-Smoking Medications, Changes in Thinking and Behavior, Depression, and Suicidal Thoughts or Actions.”
Most people should take Zyban () for at least 7 to 12 weeks. Some people may need to take Zyban () for a longer period of time to assist in their smoking cessation efforts. Follow your doctor’s instructions.
It takes about 1 week for Zyban () to start working. For your best chance of quitting, you should not stop smoking until you have been taking Zyban () for 1 week. You should set a date to stop smoking during the second week you’re taking Zyban () .
It is not physically dangerous to smoke and use Zyban () at the same time. But you will seriously lower your chance of breaking your smoking habit if you smoke after the date you set to stop smoking.
Yes, Zyban () and nicotine patches can be used at the same time but should only be used together under the supervision of your doctor. Using Zyban () and nicotine patches together may raise your blood pressure, sometimes severely. Tell your doctor if you are planning to use nicotine replacement therapy because your doctor should check your blood pressure regularly.
Zyban () can cause serious side effects. Read this entire Medication Guide for more information about these serious side effects.
The most common side effects of Zyban () are dry mouth and trouble sleeping. These side effects are generally mild and often disappear after a few weeks. If you have trouble sleeping, do not take Zyban () too close to bedtime.
These are not all the side effects of Zyban () . For a complete list, ask your doctor or pharmacist.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Do not use Zyban () for a condition for which it was not prescribed. Do not give Zyban () to other people, even if they have the same symptoms you have. It may harm them. Keep Zyban () out of the reach of children.
This Medication Guide summarizes important information about Zyban () . For more information, talk with your doctor. You can ask your doctor or pharmacist for information about Zyban () that is written for health professionals.
Active ingredient: bupropion hydrochloride.
Inactive ingredients: carnauba wax, cysteine hydrochloride, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80 and titanium dioxide. The tablets are printed with edible black ink. In addition, the 150-mg tablet contains FD&C Blue No. 2 Lake and FD&C Red No. 40 Lake.
This Medication Guide has been approved by the U.S. Food and Drug Administration.
Zyban () , WELLBUTRIN, WELLBUTRIN SR, WELLBUTRIN XL, and PARNATE are registered trademarks of GlaxoSmithKline.
The following are registered trademarks of their respective manufacturers: NARDIL/Warner Lambert Company; MARPLAN/Oxford Pharmaceutical Services, Inc.
Distributed by:
GlaxoSmithKline
Research Triangle Park, NC 27709
Manufactured by:
GlaxoSmithKline
Research Triangle Park
or DSM Pharmaceuticals, Inc.
Greenville, NC 27834
©2010, GlaxoSmithKline. All rights reserved.
September 2010
ZYB:6MG
Zyban () Principal Display Panel
Each tablet contains 150 mg of bupropion HCl.
See prescribing information for dosage information.
Store at controlled room temperature, 20 to 25C (68 to 77F) (see USP).
Mfd by: GlaxoSmithKline
Research Triangle Park, NC 27709
or DSM Pharmaceuticals, Inc.
Greenville, NC 27834
Made in Germany
10000000090980 Rev. 2/11
