Other
SUICIDALITY AND ANTIDEPRESSANT DRUGS
Antidepressants increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults in short-term trials. These trials did not show an increase in the risk of suicidal thoughts and behavior with antidepressant use in subjects over age 24; there was a reduction in risk with antidepressant use in subjects aged 65 and older [see Warnings and Precautions (5.1)] .
In patients of all ages who are started on antidepressant therapy, monitor closely for worsening, and for emergence of suicidal thoughts and behaviors. Advise families and caregivers of the need for close observation and communication with the prescriber [see Warnings and Precautions (5.1)] .
Incidence of Seizure with Bupropion Use
When bupropion hydrochloride extended-release (SR) tablets are dosed up to 300 mg/day, the incidence of seizure is approximately 0.1% (1/1,000) and increases to approximately 0.4% (4/1,000) at the maximum recommended dose of 400 mg/day.
The risk of seizure can be reduced if the dose of bupropion hydrochloride extended-release (SR) tablets does not exceed 400 mg/day, given as 200 mg twice daily, and the titration rate is gradual.
Adverse Reactions Leading to Discontinuation of Treatment
In placebo-controlled clinical trials, 4%, 9%, and 11% of the placebo, 300-mg/day, and 400-mg/day groups, respectively, discontinued treatment due to adverse reactions. The specific adverse reactions leading to discontinuation in at least 1% of the 300-mg/day or 400-mg/day groups and at a rate at least twice the placebo rate are listed in Table 2.
| Adverse Reaction | Placebo (n=385) | Bupropion hydrochloride extended-release (SR) tablets 300 mg/day (n=376) | Bupropion hydrochloride extended-release (SR) tablets 400 mg/day (n=114) |
|---|---|---|---|
Rash | 0.0% | 2.4% | 0.9% |
Nausea | 0.3% | 0.8% | 1.8% |
Agitation | 0.3% | 0.3% | 1.8% |
Migraine | 0.3% | 0.0% | 1.8% |
Commonly Observed Adverse Reactions
Adverse reactions from Table 3 occurring in at least 5% of subjects treated with bupropion hydrochloride extended-release (SR) tablets and at a rate at least twice the placebo rate are listed below for the 300- and 400-mg/day dose groups.
Bupropion hydrochloride extended-release (SR) tablets 300 mg/day:
Anorexia, dry mouth, rash, sweating, tinnitus, and tremor.
Bupropion hydrochloride extended-release (SR) tablets 400 mg/day:
Abdominal pain, agitation, anxiety, dizziness, dry mouth, insomnia, myalgia, nausea, palpitation, pharyngitis, sweating, tinnitus, and urinary frequency.
Adverse reactions reported in placebo-controlled trials are presented in Table 3. Reported adverse reactions were classified using a COSTART-based Dictionary.
Body System/Adverse Reaction | Bupropion hydrochloride extended-release (SR) tablets 300 mg/day
| Bupropion hydrochloride extended-release (SR) tablets 400 mg/day (n = 114) | Placebo
|
Body (general) | |||
| 26% | 25% | 23% |
| 8% | 9% | 6% |
| 3% | 9% | 2% |
| 2% | 4% | 2% |
| 3% | 4% | 1% |
| 2% | 3% | 2% |
| 1% | 2% | — |
Cardiovascular | |||
| 2% | 6% | 2% |
| 1% | 4% | — |
| 1% | 4% | 1% |
| 1% | 3% | 1% |
Digestive | |||
| 17% | 24% | 7% |
| 13% | 18% | 8% |
| 10% | 5% | 7% |
| 5% | 7% | 6% |
| 5% | 3% | 2% |
| 4% | 2% | 2% |
| 0% | 2% | 0% |
Musculoskeletal | |||
| 2% | 6% | 3% |
| 1% | 4% | 1% |
| 0% | 2% | 0% |
| 1% | 2% | — |
Nervous system | |||
| 11% | 16% | 6% |
| 7% | 11% | 5% |
| 3% | 9% | 2% |
| 5% | 6% | 3% |
| 6% | 3% | 1% |
| 5% | 3% | 3% |
| 2% | 3% | 2% |
| 3% | 2% | 2% |
| — | 3% | 1% |
| 1% | 2% | 1% |
| 2% | 1% | 1% |
Respiratory | |||
| 3% | 11% | 2% |
| 3% | 1% | 2% |
| 1% | 2% | 1% |
Skin | |||
| 6% | 5% | 2% |
| 5% | 4% | 1% |
| 2% | 4% | 2% |
| 2% | 1% | 0% |
Special senses | |||
| 6% | 6% | 2% |
| 2% | 4% | — |
| 3% | 2% | 2% |
Urogenital | |||
| 2% | 5% | 2% |
| — | 2% | 0% |
| 0% | 2% | — |
| 1% | 0% | — |
— Hyphen denotes adverse events occurring in greater than 0 but less than 0.5% of subjects. | |||
Other Adverse Reactions Observed during the Clinical Development of Bupropion
In addition to the adverse reactions noted above, the following adverse reactions have been reported in clinical trials with the sustained-release formulation of bupropion in depressed subjects and in nondepressed smokers, as well as in clinical trials with the immediate-release formulation of bupropion.
Adverse reaction frequencies represent the proportion of subjects who experienced a treatment-emergent adverse reaction on at least one occasion in placebo-controlled trials for depression (n = 987) or smoking cessation (n = 1,013), or subjects who experienced an adverse reaction requiring discontinuation of treatment in an open-label surveillance trial with bupropion hydrochloride extended-release (SR) tablets (n = 3,100). All treatment-emergent adverse reactions are included except those listed in Table 3, those listed in other safety-related sections of the prescribing information, those subsumed under COSTART terms that are either overly general or excessively specific so as to be uninformative, those not reasonably associated with the use of the drug, and those that were not serious and occurred in fewer than 2 subjects.
Adverse reactions are further categorized by body system and listed in order of decreasing frequency according to the following definitions of frequency: Frequent adverse reactions are defined as those occurring in at least 1/100 subjects. Infrequent adverse reactions are those occurring in 1/100 to 1/1,000 subjects, while rare events are those occurring in less than 1/1,000 subjects.
Body (General):Infrequent were chills, facial edema, and photosensitivity. Rare was malaise.
Cardiovascular:Infrequent were postural hypotension, stroke, tachycardia, and vasodilation. Rare were syncope and myocardial infarction.
Digestive:Infrequent were abnormal liver function, bruxism, gastric reflux, gingivitis, increased salivation, jaundice, mouth ulcers, stomatitis, and thirst. Rare was edema of tongue.
Hemic and Lymphatic:Infrequent was ecchymosis.
Metabolic and Nutritional:Infrequent were edema and peripheral edema.
Musculoskeletal:Infrequent were leg cramps.
Nervous System:Infrequent were abnormal coordination, decreased libido, depersonalization, dysphoria, emotional lability, hostility, hyperkinesia, hypertonia, hypesthesia, suicidal ideation, and vertigo. Rare were amnesia, ataxia, derealization, and hypomania.
Respiratory:Rare was bronchospasm.
Special Senses:Infrequent were accommodation abnormality and dry eye.
Urogenital:Infrequent were impotence, polyuria, and prostate disorder.
Changes in Body Weight
In placebo-controlled trials, subjects experienced weight gain or weight loss as shown in Table 4.
Weight Change | Bupropion hydrochloride extended-release (SR) tablets 300 mg/day
| Bupropion hydrochloride extended-release (SR) tablets 400 mg/day
| Placebo
|
Gained >5 lbs. | 3% | 2% | 4% |
Lost >5 lbs. | 14% | 19% | 6% |
In clinical trials conducted with the immediate-release formulation of bupropion, 35% of subjects receiving tricyclic antidepressants gained weight, compared with 9% of subjects treated with the immediate-release formulation of bupropion. If weight loss is a major presenting sign of a patient’s depressive illness, the anorectic and/or weight-reducing potential of bupropion hydrochloride extended-release (SR) tablets should be considered.
Inhibitors of CYP2B6
Ticlopidine and Clopidogrel:Concomitant treatment with these drugs can increase bupropion exposure but decrease hydroxybupropion exposure. Based on clinical response, dosage adjustment of bupropion hydrochloride extended-release (SR) tablets may be necessary when coadministered with CYP2B6 inhibitors (e.g., ticlopidine or clopidogrel) [see Clinical Pharmacology (12.3)] .
Inducers of CYP2B6
Ritonavir, Lopinavir, and Efavirenz:Concomitant treatment with these drugs can decrease bupropion and hydroxybupropion exposure. Dosage increase of bupropion hydrochloride extended-release (SR) tablets may be necessary when coadministered with ritonavir, lopinavir, or efavirenz [see Clinical Pharmacology (12.3)] but should not exceed the maximum recommended dose.
Carbamazepine, Phenobarbital, Phenytoin:While not systematically studied, these drugs may induce the metabolism of bupropion and may decrease bupropion exposure [see Clinical Pharmacology (12.3)] . If bupropion is used concomitantly with a CYP inducer, it may be necessary to increase the dose of bupropion, but the maximum recommended dose should not be exceeded.
Drugs Metabolized by CYP2D6
Bupropion and its metabolites (erythrohydrobupropion, threohydrobupropion, hydroxybupropion) are CYP2D6 inhibitors. Therefore, coadministration of bupropion hydrochloride extended-release (SR) tablets with drugs that are metabolized by CYP2D6 can increase the exposures of drugs that are substrates of CYP2D6. Such drugs include certain antidepressants (e.g., venlafaxine, nortriptyline, imipramine, desipramine, paroxetine, fluoxetine, and sertraline), antipsychotics (e.g., haloperidol, risperidone, thioridazine), beta-blockers (e.g., metoprolol), and Type 1C antiarrhythmics (e.g., propafenone and flecainide). When used concomitantly with bupropion hydrochloride extended-release (SR) tablets, it may be necessary to decrease the dose of these CYP2D6 substrates, particularly for drugs with a narrow therapeutic index.
Drugs that require metabolic activation by CYP2D6 to be effective (e.g., tamoxifen) theoretically could have reduced efficacy when administered concomitantly with inhibitors of CYP2D6 such as bupropion. Patients treated concomitantly with bupropion hydrochloride extended-release (SR) tablets and such drugs may require increased doses of the drug [see Clinical Pharmacology (12.3)] .
Digoxin
Coadministration of bupropion hydrochloride extended-release (SR) tablets with digoxin may decrease plasma digoxin levels. Monitor plasma digoxin levels in patients treated concomitantly with bupropion hydrochloride extended-release (SR) tablets and digoxin [see Clinical Pharmacology (
12.3)].
Humans
Controlled clinical trials conducted in normal volunteers, in subjects with a history of multiple drug abuse, and in depressed subjects showed some increase in motor activity and agitation/excitement, often typical of central stimulant activity.
In a population of individuals experienced with drugs of abuse, a single oral dose of 400 mg of bupropion produced mild amphetamine-like activity as compared with placebo on the Morphine-Benzedrine Subscale of the Addiction Research Center Inventories (ARCI) and a score greater than placebo but less than 15 mg of the Schedule II stimulant dextroamphetamine on the Liking Scale of the ARCI. These scales measure general feelings of euphoria and drug liking which are often associated with abuse potential.
Findings in clinical trials, however, are not known to reliably predict the abuse potential of drugs. Nonetheless, evidence from single-dose trials does suggest that the recommended daily dosage of bupropion when administered orally in divided doses is not likely to be significantly reinforcing to amphetamine or CNS stimulant abusers. However, higher doses (which could not be tested because of the risk of seizure) might be modestly attractive to those who abuse CNS stimulant drugs.
Bupropion hydrochloride extended-release (SR) tablets are intended for oral use only. The inhalation of crushed tablets or injection of dissolved bupropion has been reported. Seizures and/or cases of death have been reported when bupropion has been administered intranasally or by parenteral injection.
Animals
Studies in rodents and primates demonstrated that bupropion exhibits some pharmacologic actions common to psychostimulants. In rodents, it has been shown to increase locomotor activity, elicit a mild stereotyped behavior response, and increase rates of responding in several schedule-controlled behavior paradigms. In primate models assessing the positive-reinforcing effects of psychoactive drugs, bupropion was self-administered intravenously. In rats, bupropion produced amphetamine-like and cocaine-like discriminative stimulus effects in drug discrimination paradigms used to characterize the subjective effects of psychoactive drugs.
Absorption
The absolute bioavailability of bupropion hydrochloride extended-release (SR) tablets in humans has not been determined because an intravenous formulation for human use is not available. However, it appears likely that only a small proportion of any orally administered dose reaches the systemic circulation intact. In rat and dog studies, the bioavailability of bupropion ranged from 5% to 20%.
In humans, following oral administration of bupropion hydrochloride extended-release (SR) tablets, peak plasma concentration (C max) of bupropion is usually achieved within 3 hours.
In a trial comparing chronic dosing with bupropion hydrochloride extended-release (SR) tablets 150 mg twice daily to bupropion immediate-release formulation 100 mg 3 times daily, the steady state C maxfor bupropion after bupropion hydrochloride extended-release (SR) tablets administration was approximately 85% of those achieved after bupropion immediate-release formulation administration. Exposure (AUC) to bupropion was equivalent for both formulations. Bioequivalence was also demonstrated for all three major active metabolites (i.e., hydroxybupropion, threohydrobupropion and erythrohydrobupropion) for both C maxand AUC. Thus, at steady state, bupropion hydrochloride extended-release (SR) tablets given twice daily, and the immediate-release formulation of bupropion given 3 times daily, are essentially bioequivalent for both bupropion and the 3 quantitatively important metabolites.
Bupropion hydrochloride extended-release (SR) tablets can be taken with or without food. Bupropion C maxand AUC were increased by 11% to 35% and 16% to 19%, respectively, when bupropion hydrochloride extended-release (SR) tablets were administered with food to healthy volunteers in three trials. The food effect is not considered clinically significant.
Distribution
In vitrotests show that bupropion is 84% bound to human plasma proteins at concentrations up to 200 mcg/mL. The extent of protein binding of the hydroxybupropion metabolite is similar to that for bupropion; whereas, the extent of protein binding of the threohydrobupropion metabolite is about half that seen with bupropion.
Metabolism
Bupropion is extensively metabolized in humans. Three metabolites are active: hydroxybupropion, which is formed via hydroxylation of the tert-butyl group of bupropion, and the amino-alcohol isomers, threohydrobupropion and erythrohydrobupropion, which are formed via reduction of the carbonyl group. In vitrofindings suggest that CYP2B6 is the principal isoenzyme involved in the formation of hydroxybupropion, while cytochrome P450 enzymes are not involved in the formation of threohydrobupropion. Oxidation of the bupropion side chain results in the formation of a glycine conjugate of meta-chlorobenzoic acid, which is then excreted as the major urinary metabolite. The potency and toxicity of the metabolites relative to bupropion have not been fully characterized. However, it has been demonstrated in an antidepressant screening test in mice that hydroxybupropion is one-half as potent as bupropion, while threohydrobupropion and erythrohydrobupropion are 5-fold less potent than bupropion. This may be of clinical importance because the plasma concentrations of the metabolites are as high as or higher than those of bupropion.
Following a single-dose administration of bupropion hydrochloride extended-release (SR) tablets in humans, C maxof hydroxybupropion occurs approximately 6 hours post-dose and is 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.
Elimination
Following oral administration of 200 mg of 14C-bupropion in humans, 87% and 10% of the radioactive dose were recovered in the urine and feces, respectively. Only 0.5% of the oral dose was excreted as unchanged bupropion.
Specific Populations
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.
Patients with Renal Impairment:There is limited information on the pharmacokinetics of bupropion in patients with renal impairment. An inter-trial comparison between normal subjects and subjects with end-stage renal failure demonstrated that the parent drug C maxand AUC values were comparable in the 2 groups, whereas the hydroxybupropion and threohydrobupropion metabolites had a 2.3- and 2.8-fold increase, respectively, in AUC for subjects with end-stage renal failure. A second trial, comparing normal subjects and subjects with moderate-to-severe renal impairment (GFR 30.9 ± 10.8 mL/min), showed that after a single 150-mg dose of sustained-release bupropion, exposure to bupropion was approximately 2-fold higher in subjects with impaired renal function, while levels of the hydroxybupropion and threo/erythrohydrobupropion (combined) metabolites were similar in the 2 groups. Bupropion is extensively metabolized in the liver to active metabolites, which are further metabolized and subsequently excreted by the kidneys. The elimination of the major metabolites of bupropion may be reduced by impaired renal function. Bupropion hydrochloride extended-release (SR) tablets should be used with caution in patients with renal impairment and a reduced frequency and/or dose should be considered [see Use in Specific Populations (8.6)].
Patients with Hepatic Impairment:The effect of hepatic impairment on the pharmacokinetics of bupropion was characterized in 2 single-dose trials, one in subjects with alcoholic liver disease and one in subjects with mild-to-severe cirrhosis. The first trial demonstrated that the half-life of hydroxybupropion was significantly longer in 8 subjects with alcoholic liver disease than in 8 healthy volunteers (32 ± 14 hours versus 21 ± 5 hours, respectively). Although not statistically significant, the AUCs for bupropion and hydroxybupropion were more variable and tended to be greater (by 53% to 57%) in volunteers with alcoholic liver disease. The differences in half-life for bupropion and the other metabolites in the 2 groups were minimal.
The second trial demonstrated no statistically significant differences in the pharmacokinetics of bupropion and its active metabolites in 9 subjects with mild-to-moderate hepatic cirrhosis compared with 8 healthy volunteers. However, more variability was observed in some of the pharmacokinetic parameters for bupropion (AUC, C max, and T max) and its active metabolites (t ½) in subjects with mild–to-moderate hepatic cirrhosis. In subjects with severe hepatic cirrhosis, significant alterations in the pharmacokinetics of bupropion and its metabolites were seen (Table 5).
| C max | AUC | t ½ | T max | |
|---|---|---|---|---|
Bupropion | 1.69 | 3.12 | 1.43 | 0.5 h |
Hydroxybupropion | 0.31 | 1.28 | 3.88 | 19 h |
Threo/erythrohydrobupropion amino alcohol | 0.69 | 2.48 | 1.96 | 20 h |
Patients with Left Ventricular Dysfunction:During a chronic dosing trial with bupropion in 14 depressed subjects with left ventricular dysfunction (history of CHF or an enlarged heart on x-ray), there was no apparent effect on the pharmacokinetics of bupropion or its metabolites, compared with healthy volunteers.
Age:The effects of age on the pharmacokinetics of bupropion and its metabolites have not been fully characterized, but an exploration of steady-state bupropion concentrations from several depression efficacy trials involving subjects dosed in a range of 300 to 750 mg/day, on a 3-times-daily schedule, revealed no relationship between age (18 to 83 years) and plasma concentration of bupropion. A single-dose pharmacokinetic trial demonstrated that the disposition of bupropion and its metabolites in elderly subjects was similar to that of younger subjects. These data suggest there is no prominent effect of age on bupropion concentration; however, another single- and multiple-dose pharmacokinetics trial suggested that the elderly are at increased risk for accumulation of bupropion and its metabolites [see Use in Specific Populations (8.5)] .
Male and Female Patients:Pooled analysis of bupropion pharmacokinetic data from 90 healthy male and 90 healthy female volunteers revealed no sex-related differences in the peak plasma concentrations of bupropion. The mean systemic exposure (AUC) was approximately 13% higher in male volunteers compared with female volunteers. The clinical significance of this finding is unknown.
Smokers: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 bupropion, there were no statistically significant differences in C max, half-life, T max, AUC, or clearance of bupropion or its active metabolites between smokers and nonsmokers.
Drug Interaction Studies
Potential for Other Drugs to Affect Bupropion Hydrochloride Extended-release (SR) Tablets: In vitrostudies indicate that bupropion is primarily metabolized to hydroxybupropion by CYP2B6. Therefore, the potential exists for drug interactions between bupropion hydrochloride extended-release (SR) tablets and drugs that are inhibitors or inducers of CYP2B6. In addition, in vitrostudies suggest that paroxetine, sertraline, norfluoxetine, fluvoxamine, and nelfinavir inhibit the hydroxylation of bupropion.
Inhibitors of CYP2B6: Ticlopidine, Clopidogrel:In a trial in healthy male volunteers, clopidogrel 75 mg once daily or ticlopidine 250 mg twice daily increased exposures (C maxand AUC) of bupropion by 40% and 60% for clopidogrel, and by 38% and 85% for ticlopidine, respectively. The exposures (C maxand AUC) of hydroxybupropion were decreased 50% and 52%, respectively, by clopidogrel, and 78% and 84%, respectively, by ticlopidine. This effect is thought to be due to the inhibition of the CYP2B6-catalyzed bupropion hydroxylation.
Prasugrel:Prasugrel is a weak inhibitor of CYP2B6. In healthy subjects, prasugrel increased bupropion C maxand AUC values by 14% and 18%, respectively, and decreased C maxand AUC values of hydroxybupropion, an active metabolite of bupropion, by 32% and 24%, respectively.
Cimetidine:The threohydrobupropion metabolite of bupropion does not appear to be produced by cytochrome P450 enzymes. 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 bupropion 300 mg with and without cimetidine 800 mg, the pharmacokinetics of bupropion and hydroxybupropion were unaffected. However, there were 16% and 32% increases in the AUC and C max, respectively, of the combined moieties of threohydrobupropion and erythrohydrobupropion.
Citalopram:Citalopram did not affect the pharmacokinetics of bupropion and its three metabolites.
Inducers of CYP2B6: Ritonavir and Lopinavir:In a healthy volunteer trial, ritonavir 100 mg twice daily reduced the AUC and C maxof 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 trial, ritonavir at a dose of 600 mg twice daily decreased the AUC and the C maxof 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 trial, lopinavir 400 mg/ritonavir 100 mg twice daily decreased bupropion AUC and C maxby 57%. The AUC and C maxof hydroxybupropion were decreased by 50% and 31%, respectively.
Efavirenz:In a trial in healthy volunteers, efavirenz 600 mg once daily for 2 weeks reduced the AUC and C maxof bupropion by approximately 55% and 34%, respectively. The AUC of hydroxybupropion was unchanged, whereas C maxof hydroxybupropion was increased by 50%.
Carbamazepine, Phenobarbital, Phenytoin: While not systematically studied, these drugs may induce the metabolism of bupropion.
Potential for Bupropion Hydrochloride Extended-release (SR) Tablets to Affect Other Drugs
Animal data indicated that bupropion may be an inducer of drug-metabolizing enzymes in humans. In one trial, 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. Nevertheless, there may be potential for clinically important alterations of blood levels of co-administered drugs.
Drugs Metabolized by CYP2D6: In vitro, bupropion and its metabolites (erythrohydrobupropion, threohydrobupropion, hydroxybupropion) are CYP2D6 inhibitors. In a clinical trial of 15 male subjects (ages 19 to 35 years) who were extensive metabolizers of CYP2D6, bupropion 300 mg/day followed by a single dose of 50 mg desipramine increased the C max, AUC, and t 1/2of desipramine by an average of approximately 2-, 5-, and 2-fold, respectively. The effect was present for at least 7 days after the last dose of bupropion. Concomitant use of bupropion with other drugs metabolized by CYP2D6 has not been formally studied.
Citalopram:Although citalopram is not primarily metabolized by CYP2D6, in one trial bupropion increased the C maxand AUC of citalopram by 30% and 40%, respectively.
Lamotrigine:Multiple oral doses of bupropion had no statistically significant effects on the single-dose pharmacokinetics of lamotrigine in 12 healthy volunteers.
Digoxin: Literature data showed that digoxin exposure was decreased when a single oral dose of 0.5-mg digoxin was administered 24 hours after a single oral dose of extended-release 150-mg bupropion in healthy volunteers.
Suicidal Thoughts and Behaviors
Instruct patients, their families, and/or their caregivers to be alert to the emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, mania, other unusual changes in behavior, worsening of depression, and suicidal ideation, especially early during antidepressant treatment and when the dose is adjusted up or down. Advise families and caregivers of patients to observe for the emergence of such symptoms on a day-to-day basis, since changes may be abrupt. Such symptoms should be reported to the patient’s prescriber or healthcare professional, especially if they are severe, abrupt in onset, or were not part of the patient’s presenting symptoms. Symptoms such as these may be associated with an increased risk for suicidal thinking and behavior and indicate a need for very close monitoring and possibly changes in the medication.
Neuropsychiatric Adverse Events and Suicide Risk in Smoking Cessation Treatment
Although bupropion hydrochloride extended-release (SR) tablets are not indicated for smoking cessation treatment, it contains the same active ingredient as ZYBAN which is approved for this use. Inform patients that some patients have experienced changes in mood (including depression and mania), psychosis, hallucinations, paranoia, delusions, homicidal ideation, aggression, hostility, agitation, anxiety, and panic, as well as suicidal ideation and suicide when attempting to quit smoking while taking bupropion. Instruct patients to discontinue bupropion and contact a healthcare professional if they experience such symptoms [see Warnings and Precautions ( 5.2), Adverse Reactions ( 6.2)].
Severe Allergic Reactions
Educate patients on the symptoms of hypersensitivity and to discontinue bupropion hydrochloride extended-release (SR) tablets if they have a severe allergic reaction.
Seizure
Instruct patients to discontinue and not restart bupropion hydrochloride extended-release (SR) tablets if they experience a seizure while on treatment. Advise patients that the excessive use or abrupt discontinuation of alcohol, benzodiazepines, antiepileptic drugs, or sedatives/hypnotics can increase the risk of seizure. Advise patients to minimize or avoid use of alcohol.
As the dose is increased during initial titration to doses above 150 mg/day, instruct patients to take bupropion hydrochloride extended-release (SR) tablets in 2 divided doses, preferably with at least 8 hours between successive doses, to minimize the risk of seizures.
Angle-Closure Glaucoma
Patients should be advised that taking bupropion hydrochloride extended-release (SR) tablets can cause mild pupillary dilation, which in susceptible individuals, can lead to an episode of angle-closure glaucoma. Pre-existing glaucoma is almost always open-angle glaucoma because angle-closure glaucoma, when diagnosed, can be treated definitively with iridectomy. Open-angle glaucoma is not a risk factor for angle-closure glaucoma. Patients may wish to be examined to determine whether they are susceptible to angle closure, and have a prophylactic procedure (e.g., iridectomy), if they are susceptible [see Warnings and Precautions (5.7)] .
Bupropion-Containing Products
Educate patients that bupropion hydrochloride extended-release (SR) tablets contain the same active ingredient (bupropion hydrochloride) found in ZYBAN, which is used as an aid to smoking cessation treatment, and that bupropion hydrochloride extended-release (SR) tablets should not be used in combination with ZYBAN or any other medications that contain bupropion (such as bupropion hydrochloride extended-release (SR) tablets, the immediate-release formulation and bupropion hydrochloride extended-release (XL) tablets or FORFIVO XL, the extended- release formulations, and APLENZIN, the extended-release formulation of bupropion hydrobromide). In addition, there are a number of generic bupropion HCl products for the immediate-, sustained-, and extended-release formulations.
Potential for Cognitive and Motor Impairment
Advise patients that any CNS-active drug like bupropion hydrochloride extended-release (SR) tablets may impair their ability to perform tasks requiring judgment or motor and cognitive skills. Advise patients that until they are reasonably certain that bupropion hydrochloride extended-release (SR) tablets do not adversely affect their performance, they should refrain from driving an automobile or operating complex, hazardous machinery. Bupropion hydrochloride extended-release (SR) tablets may lead to decreased alcohol tolerance.
Concomitant Medications
Counsel patients to notify their healthcare provider if they are taking or plan to take any prescription or over-the-counter drugs because bupropion hydrochloride extended-release (SR) tablets and other drugs may affect each others’ metabolisms.
Pregnancy
Advise patients to notify their healthcare provider if they become pregnant or intend to become pregnant during therapy with bupropion hydrochloride extended-release (SR) tablets. Advise patients that there is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to bupropion hydrochloride extended-release (SR) tablets during pregnancy [see Use in Specific Populations (8.1)].
Storage Information
Instruct patients to store bupropion hydrochloride extended-release (SR) tablets at room temperature, between 68°F and 77°F (20°C to 25°C) and keep the tablets dry and out of the light.
Administration Information
Instruct patients to swallow bupropion hydrochloride extended-release (SR) tablets whole so that the release rate is not altered. Do not chew, divide, or crush tablets; they are designed to slowly release drug in the body. When patients take more than 150 mg/day, instruct them to take bupropion hydrochloride extended-release (SR) tablets in 2 doses at least 8 hours apart, to minimize the risk of seizures. Instruct patients if they miss a dose, not to take an extra tablet to make up for the missed dose and to take the next tablet at the regular time because of the dose-related risk of seizure. Instruct patients that bupropion hydrochloride extended-release (SR) tablets may have an odor. Bupropion hydrochloride extended-release (SR) tablets can be taken with or without food.
WELLBUTRIN, WELLBUTRIN SR, WELLBUTRIN XL, and ZYBAN are trademarks owned by or licensed to the GSK group of companies. The other brands listed are trademarks of their respective owners.
You may report side effects to Solco Healthcare US LLC. at 1-866-257-2597 or FDA at 1-800-FDA-1088.
Dispense with Medication Guide available at: www.solcohealthcare.com/medguide/bupropion-sr-tablets.pdf
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