Bupropion HCL ER(SR)

7.1 Potential for Other Drugs to Affect Bupropion Hydrochloride Extended-Release Tablets (SR) Bupropion is primarily metabolized to hydroxybupropion by CYP2B6. Therefore, the potential exists for drug interactions between bupropion hydrochloride extended-release tablets (SR) and drugs that are inhibitors or inducers of CYP2B6. 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 tablets (SR) 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 tablets (SR) 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. 7.2 Potential for Bupropion Hydrochloride Extended-Release Tablets (SR) to Affect Other Drugs Drugs Metabolized by CYP2D6 Bupropion and its metabolites (erythrohydrobupropion, threohydrobupropion, hydroxybupropion) are CYP2D6 inhibitors. Therefore, coadministration of bupropion hydrochloride extended-release tablets (SR) 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 tablets (SR), 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 tablets (SR) and such drugs may require increased doses of the drug [see Clinical Pharmacology (12.3)]. Digoxin Coadministration of bupropion hydrochloride extended-release tablets (SR) with digoxin may decrease plasma digoxin levels. Monitor plasma digoxin levels in patients treated concomitantly with bupropion hydrochloride extended-release tablets (SR) and digoxin [see Clinical Pharmacology (12.3)] . 7.3 Drugs that Lower Seizure Threshold Use extreme caution when coadministering bupropion hydrochloride extended-release tablets (SR) with other drugs that lower seizure threshold (e.g., other bupropion products, antipsychotics, antidepressants, theophylline, or systemic corticosteroids). Use low initial doses and increase the dose gradually [see Contraindications (4), Warnings and Precautions (5.3)]. 7.4 Dopaminergic Drugs (Levodopa and Amantadine) Bupropion, levodopa, and amantadine have dopamine agonist effects. CNS toxicity has been reported when bupropion was coadministered with levodopa or amantadine. Adverse reactions have included restlessness, agitation, tremor, ataxia, gait disturbance, vertigo, and dizziness. It is presumed that the toxicity results from cumulative dopamine agonist effects. Use caution when administering bupropion hydrochloride extended-release tablets (SR) concomitantly with these drugs. 7.5 Use with Alcohol In postmarketing experience, there have been rare reports of adverse neuropsychiatric events or reduced alcohol tolerance in patients who were drinking alcohol during treatment with bupropion hydrochloride extended-release tablets (SR). The consumption of alcohol during treatment with bupropion hydrochloride extended-release tablets (SR) should be minimized or avoided. 7.6 MAO Inhibitors Bupropion inhibits the reuptake of dopamine and norepinephrine. Concomitant use of MAOIs and bupropion is contraindicated because there is an increased risk of hypertensive reactions if bupropion is used concomitantly with MAOIs. Studies in animals demonstrate that the acute toxicity of bupropion is enhanced by the MAO inhibitor phenelzine. At least 14 days should elapse between discontinuation of an MAOI intended to treat depression and initiation of treatment with bupropion hydrochloride extended-release tablets (SR). Conversely, at least 14 days should be allowed after stopping bupropion hydrochloride extended-release tablets (SR) before starting an MAOI antidepressant [see Dosage and Administration (2.4, 2.5), Contraindications (4)]. 7.7 Drug-Laboratory Test Interactions False-positive urine immunoassay screening tests for amphetamines have been reported in patients taking bupropion. This is due to lack of specificity of some screening tests. False-positive test results may result even following discontinuation of bupropion therapy. Confirmatory tests, such as gas chromatography/mass spectrometry, will distinguish bupropion from amphetamines.

Bupropion hydrochloride extended-release tablets (SR) are indicated for the treatment of major depressive disorder (MDD), as defined by the Diagnostic and Statistical Manual (DSM). The efficacy of bupropion in the treatment of a major depressive episode was established in two 4-week controlled inpatient trials and one 6-week controlled outpatient trial of adult subjects with MDD [see Clinical Studies (14)]. The efficacy of bupropion hydrochloride extended-release tablets (SR) in maintaining an antidepressant response for up to 44 weeks following 8 weeks of acute treatment was demonstrated in a placebo-controlled trial [see Clinical Studies (14)].

2.1 General Instructions for Use To minimize the risk of seizure, increase the dose gradually [see Warnings and Precautions (5.3)] . Bupropion hydrochloride extended-release tablets (SR) should be swallowed whole and not crushed, divided, or chewed. Bupropion hydrochloride extended-release tablets (SR) may be taken with or without food. The usual adult target dose for bupropion hydrochloride extended-release (SR) tablet is 300 mg/day, given as 150 mg twice daily. Initiate dosing with 150 mg/day given as a single daily dose in the morning. After 3 days of dosing, the dose may be increased to the 300 mg/day target dose, given as 150 mg twice daily. There should be an interval of at least 8 hours between successive doses. A maximum of 400 mg/day, given as 200 mg twice daily, may be considered for patients in whom no clinical improvement is noted after several weeks of treatment at 300 mg/day. To avoid high peak concentrations of bupropion and/or its metabolites, do not exceed 200 mg in any single dose. It is generally agreed that acute episodes of depression require several months or longer of antidepressant drug treatment beyond the response in the acute episode. It is unknown whether the dose of bupropion hydrochloride extended-release tablets (SR) needed for maintenance treatment is identical to the dose that provided an initial response. Periodically reassess the need for maintenance treatment and the appropriate dose for such treatment. 2.2 Dose Adjustment in Patients with Hepatic Impairment In patients with moderate to severe hepatic impairment (Child-Pugh score: 7 to 15), the maximum dose of bupropion hydrochloride extended-release tablets (SR) is 100 mg/day or 150 mg every other day. In patients with mild hepatic impairment (Child-Pugh score: 5 to 6), consider reducing the dose and/or frequency of dosing [see Use in Specific Populations (8.7), Clinical Pharmacology (12.3)] . 2.3 Dose Adjustment in Patients with Renal Impairment Consider reducing the dose and/or frequency of bupropion hydrochloride extended-release tablets (SR) in patients with renal impairment (Glomerular Filtration Rate [GFR] less than 90 mL/min) [see Use in Specific Populations (8.6), Clinical Pharmacology (12.3)] . 2.4 Switching a Patient to or from a Monoamine Oxidase Inhibitor (MAOI) Antidepressant At least 14 days should elapse between discontinuation of an MAOI intended to treat depression and initiation of therapy with bupropion hydrochloride extended-release tablets (SR). Conversely, at least 14 days should be allowed after stopping bupropion hydrochloride extended-release tablets (SR) before starting an MAOI antidepressant [see Contraindications (4), Drug Interactions (7.6)] . 2.5 Use of Bupropion Hydrochloride Extended-Release Tablets (SR) with Reversible MAOIs Such as Linezolid or Methylene Blue Do not start bupropion hydrochloride extended-release tablets (SR) in a patient who is being treated with a reversible MAOI such as linezolid or intravenous methylene blue. Drug interactions can increase the risk of hypertensive reactions. In a patient who requires more urgent treatment of a psychiatric condition, non-pharmacological interventions, including hospitalization, should be considered [see Contraindications (4), Drug Interactions (7.6)] . In some cases, a patient already receiving therapy with bupropion hydrochloride extended-release tablets (SR) may require urgent treatment with linezolid or intravenous methylene blue. If acceptable alternatives to linezolid or intravenous methylene blue treatment are not available and the potential benefits of linezolid or intravenous methylene blue treatment are judged to outweigh the risks of hypertensive reactions in a particular patient, bupropion hydrochloride extended-release tablets (SR) should be stopped promptly, and linezolid or intravenous methylene blue can be administered. The patient should be monitored for 2 weeks or until 24 hours after the last dose of linezolid or intravenous methylene blue, whichever comes first. Therapy with bupropion hydrochloride extended-release tablets (SR) may be resumed 24 hours after the last dose of linezolid or intravenous methylene blue. The risk of administering methylene blue by non-intravenous routes (such as oral tablets or by local injection) or in intravenous doses much lower than 1 mg/kg with bupropion hydrochloride extended-release tablets (SR) is unclear. The clinician should, nevertheless, be aware of the possibility of a drug interaction with such use [see Contraindications (4), Drug Interactions (7.6)] .

The following adverse reactions are discussed in greater detail in other sections of the labeling: • Suicidal thoughts and behaviors in adolescents and young adults [see Boxed Warning, Warnings and Precautions (5.1)] • Neuropsychiatric symptoms and suicide risk in smoking cessation treatment [see Warnings and Precautions (5.2)] • Seizure [see Warnings and Precautions (5.3)] • Hypertension [see Warnings and Precautions (5.4)] • Activation of mania or hypomania [see Warnings and Precautions (5.5)] • Psychosis and other neuropsychiatric reactions [see Warnings and Precautions (5.6)] • Angle-closure glaucoma [see Warnings and Precautions (5.7)] • Hypersensitivity reactions [see Warnings and Precautions (5.8)] 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. 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. Table 2. Treatment Discontinuations Due to Adverse Reactions in Placebo-Controlled Trials Adverse Reaction Placebo (n = 385) Bupropion hydrochloride extended-release tablets (SR) 300 mg/day (n = 376) Bupropion hydrochloride extended-release tablets (SR) 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 tablets (SR) 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 tablets (SR) 300 mg/day:Anorexia, dry mouth, rash, sweating, tinnitus, and tremor. Bupropion hydrochloride extended-release tablets (SR) 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. Table 3. Adverse Reactions Reported by at Least 1% of Subjects and at a Greater Frequency than Placebo in Controlled Clinical Trials Body System/ Adverse Reaction Bupropion hydrochloride extended-release tablets (SR) 300 mg/day (n = 376) Bupropion hydrochloride extended-release tablets (SR) 400 mg/day (n = 114) Placebo (n = 385) Body (general) Headache 26% 25% 23% Infection 8% 9% 6% Abdominal pain 3% 9% 2% Asthenia 2% 4% 2% Chest pain 3% 4% 1% Pain 2% 3% 2% Fever 1% 2% — Cardiovascular Palpitation 2% 6% 2% Flushing 1% 4% — Migraine 1% 4% 1% Hot flashes 1% 3% 1% Digestive Dry mouth 17% 24% 7% Nausea 13% 18% 8% Constipation 10% 5% 7% Diarrhea 5% 7% 6% Anorexia 5% 3% 2% Vomiting 4% 2% 2% Dysphagia 0% 2% 0% Musculoskeletal Myalgia 2% 6% 3% Arthralgia 1% 4% 1% Arthritis 0% 2% 0% Twitch 1% 2% — Nervous system Insomnia 11% 16% 6% Dizziness 7% 11% 5% Agitation 3% 9% 2% Anxiety 5% 6% 3% Tremor 6% 3% 1% Nervousness 5% 3% 3% Somnolence 2% 3% 2% Irritability 3% 2% 2% Memory decreased — 3% 1% Paresthesia 1% 2% 1% Central nervous system stimulation 2% 1% 1% Respiratory Pharyngitis 3% 11% 2% Sinusitis 3% 1% 2% Increased cough 1% 2% 1% Skin Sweating 6% 5% 2% Rash 5% 4% 1% Pruritus 2% 4% 2% Urticaria 2% 1% 0% Special senses Tinnitus 6% 6% 2% Taste perversion 2% 4% — Blurred vision or diplopia 3% 2% 2% Urogenital Urinary frequency 2% 5% 2% Urinary urgency — 2% 0% Vaginal hemorrhage a 0% 2% — Urinary tract infection 1% 0% — aIncidence based on the number of female subjects. — 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 tablets (SR) (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. Table 4. Incidence of Weight Gain and Weight Loss (≥5 lbs.) in Placebo-Controlled Trials Weight Change Bupropion hydrochloride extended-release tablets (SR) 300 mg/day (n = 339) Bupropion hydrochloride extended-release tablets (SR) 400 mg/day (n = 112) Placebo (n = 347) 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 tablets (SR) should be considered. 6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of bupropion hydrochloride extended-release tablets (SR) and are not described elsewhere in the label. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Body (General) Arthralgia, myalgia, and fever with rash and other symptoms suggestive of delayed hypersensitivity. These symptoms may resemble serum sickness [see Warnings and Precautions (5.8)]. Cardiovascular Complete atrioventricular block, extrasystoles, hypotension, hypertension (in some cases severe), phlebitis, pulmonary embolism, and Brugada pattern/syndrome. Digestive Colitis, esophagitis, gastrointestinal hemorrhage, gum hemorrhage, hepatitis, intestinal perforation, pancreatitis, and stomach ulcer. Endocrine Hyperglycemia, hypoglycemia, hyponatremia, and syndrome of inappropriate antidiuretic hormone secretion. Hemic and Lymphatic Anemia, leukocytosis, leukopenia, lymphadenopathy, pancytopenia, and thrombocytopenia. Altered PT and/or INR, infrequently associated with hemorrhagic or thrombotic complications, were observed when bupropion was coadministered with warfarin. Metabolic and Nutritional Glycosuria. Musculoskeletal Muscle rigidity/fever/rhabdomyolysis and muscle weakness. Nervous System Abnormal electroencephalogram (EEG), aggression, akinesia, aphasia, coma, completed suicide, delirium, delusions, dysarthria, euphoria, extrapyramidal syndrome (dyskinesia, dystonia, hypokinesia, parkinsonism), hallucinations, increased libido, manic reaction, neuralgia, neuropathy, paranoid ideation, restlessness, suicide attempt, unmasking tardive dyskinesia, and aseptic meningitis. Respiratory Pneumonia. Skin and Subcutaneous Tissue Disorders Alopecia, angioedema, exfoliative dermatitis, hirsutism, Stevens-Johnson syndrome, acute generalized exanthematous pustulosis, and drug reaction with eosinophilia and systemic symptoms (DRESS). Special Senses Deafness, increased intraocular pressure, and mydriasis. Urogenital Abnormal ejaculation, cystitis, dyspareunia, dysuria, gynecomastia, menopause, painful erection, salpingitis, urinary incontinence, urinary retention, and vaginitis.