Duloxetine

12.1 Mechanism of Action Although the exact mechanisms of the antidepressant, central pain inhibitory and anxiolytic actions of duloxetine in humans are unknown, these actions are believed to be related to its potentiation of serotonergic and noradrenergic activity in the CNS.

1 INDICATIONS AND USAGE Duloxetine delayed-release capsules is indicated for the treatment of: Major depressive disorder in adults Generalized anxiety disorder in adults and pediatric patients 7 years of age and older Diabetic peripheral neuropathic pain in adults Fibromyalgia in adults and pediatric patients 13 years of age and older Chronic musculoskeletal pain in adults Duloxetine delayed-release capsules are a serotonin and norepinephrine reuptake inhibitor (SNRI) indicated for the treatment of the following conditions: Major depressive disorder (MDD) in adults ( 1 ) Generalized anxiety disorder (GAD) in adults and pediatric patients 7 years of age and older ( 1 ) Diabetic peripheral neuropathic pain (DPNP) in adults ( 1 ) Fibromyalgia (FM) in adults and pediatric patients 13 years of age and older ( 1 ) Chronic musculoskeletal pain in adults ( 1 )

2 DOSAGE AND ADMINISTRATION Take Duloxetine delayed-release capsules once daily, with or without food. Swallow whole; do not crush, chew, or open capsule ( 2.1 ) Indication Starting Dose Target Dose Maximum Dose MDD ( 2.2 ) 40 mg/day to 60 mg/day Acute Treatment: 40 mg/day (20 mg twice daily) to 60 mg/day (once daily or as 30 mg twice daily); Maintenance Treatment: 60 mg/day 120 mg/day GAD ( 2.3 ) Adults 60 mg/day 60 mg/day (once daily) 120 mg/day Geriatric 30 mg/day 60 mg/day (once daily) 120 mg/day Pediatrics (7 to 17 years of age) 30 mg/day 30 to 60 mg/day (once daily) 120 mg/day DPNP ( 2.4 ) 60 mg/day 60 mg/day (once daily) 60 mg/day FM ( 2.5 ) Adults and Pediatrics (13 to 17 years of age) 30 mg/day 60 mg/day (once daily) 60 mg/day Chronic Musculoskeletal Pain ( 2.6 ) 30 mg/day 60 mg/day (once daily) 60 mg/day Discontinuing Duloxetine delayed-release capsules: Gradually reduce dosage to avoid discontinuation symptoms ( 2.8 , 5.7 ) 2.1 Important Administration Instructions Administer Duloxetine delayed-release capsules orally (with or without meals) and swallow whole. Do not chew or crush, and do not open the delayed-release capsule and sprinkle its contents on food or mix with liquids because these actions might affect the enteric coating. If a dose of Duloxetine delayed-release capsules is missed, take the missed dose as soon as it is remembered. If it is almost time for the next dose, skip the missed dose and take the next dose at the regular time. Do not take two doses of Duloxetine delayed-release capsules at the same time. 2.2 Dosage for Treatment of Major Depressive Disorder in Adults The recommended starting dosage in adults with MDD is 40 mg/day (given as 20 mg twice daily) to 60 mg/day (given either once daily or as 30 mg twice daily). For some patients, it may be desirable to start at 30 mg once daily for 1 week, to allow patients to adjust to Duloxetine delayed-release capsules before increasing to 60 mg once daily. While a 120 mg/day dose was shown to be effective, there is no evidence that doses greater than 60 mg/day confer any additional benefits. Periodically reassess to determine the need for maintenance treatment and the appropriate dosage for such treatment. 2.3 Dosage for Treatment of Generalized Anxiety Disorder Recommended Dosage in Adults Less than 65 Years of Age For most adults less than 65 years of age with GAD, initiate Duloxetine delayed-release capsules 60 mg once daily. For some patients, it may be desirable to start at 30 mg once daily for 1 week, to allow patients to adjust to Duloxetine delayed-release capsules before increasing to 60 mg once daily. While a 120 mg once daily dosage was shown to be effective, there is no evidence that doses greater than 60 mg/day confer additional benefit. Nevertheless, if a decision is made to increase the dosage beyond 60 mg once daily, increase dosage in increments of 30 mg once daily. Periodically reassess to determine the continued need for maintenance treatment and the appropriate dosage for such treatment. Recommended Dosage in Geriatric Patients In geriatric patients with GAD, initiate Duloxetine delayed-release capsules at a dosage of 30 mg once daily for 2 weeks before considering an increase to the target dose of 60 mg/day. Thereafter, patients may benefit from doses above 60 mg once daily. If a decision is made to increase the dose beyond 60 mg once daily, increase dose in increments of 30 mg once daily. The maximum dose studied was 120 mg per day. Recommended Dosage in Pediatric Patients 7 to 17 Years of Age Initiate Duloxetine delayed-release capsules in pediatric patients 7 to 17 years of age with GAD at a dosage of 30 mg once daily for 2 weeks before considering an increase to 60 mg once daily. The recommended dosage range is 30 to 60 mg once daily. Some patients may benefit from dosages above 60 mg once daily. If a decision is made to increase the dose beyond 60 mg once daily, increase dosage in increments of 30 mg once daily. The maximum dose studied was 120 mg per day. 2.4 Dosage for Treatment of Diabetic Peripheral Neuropathic Pain in Adults Administer 60 mg once daily in adults with diabetic peripheral neuropathic pain. There is no evidence that doses higher than 60 mg once daily confer additional significant benefit and the higher dosage is clearly less well tolerated. For patients for whom tolerability is a concern, a lower starting dose may be considered. Since diabetes is frequently complicated by renal disease, consider a lower starting dosage and gradual increase in dosage for patients with renal impairment [see Dosage and Administration (2.7) and Use in Specific Populations (8.10) ]. 2.5 Dosage for Treatment of Fibromyalgia Recommended Dosage in Adults The recommended Duloxetine delayed-release capsules dosage is 60 mg once daily in adults with fibromyalgia. Begin treatment at 30 mg once daily for 1 week, to allow patients to adjust to Duloxetine delayed-release capsules before increasing to 60 mg once daily. S

6 ADVERSE REACTIONS The following serious adverse reactions are described below and elsewhere in the labeling: Suicidal Thoughts and Behaviors in Children, Adolescents, and Young Adults [see Boxed Warning and Warnings and Precautions (5.1) ] Hepatotoxicity [see Warnings and Precautions (5.2) ] Orthostatic Hypotension, Falls and Syncope [see Warnings and Precautions (5.3) ] Serotonin Syndrome [see Warnings and Precautions (5.4) ] Increased Risk of Bleeding [see Warnings and Precautions (5.5) ] Severe Skin Reactions [see Warnings and Precautions (5.6) ] Discontinuation Syndrome [see Warnings and Precautions (5.7) ] Activation of Mania/Hypomania [see Warnings and Precautions (5.8) ] Angle-Closure Glaucoma [see Warnings and Precautions (5.9) ] Seizures [see Warnings and Precautions (5.10) ] Increases in Blood Pressure [see Warnings and Precautions (5.11) ] Clinically Important Drug Interactions [see Warnings and Precautions (5.12) ] Hyponatremia [see Warnings and Precautions (5.13) ] Urinary Hesitation and Retention [see Warnings and Precautions (5.15) ] Sexual Dysfunction [see Warnings and Precautions (5.16) ] Most common adverse reactions (≥5% and at least twice the incidence of placebo-treated patients): ( 6.1 ) Adults : nausea, dry mouth, somnolence, constipation, decreased appetite, and hyperhidrosis Pediatric Patients : decreased weight, decreased appetite, nausea, vomiting, fatigue, and diarrhea To report SUSPECTED ADVERSE REACTIONS, contact Breckenridge Pharmaceutical, Inc. at 1-800-367-3395 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 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 to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The stated frequencies of adverse reactions represent the proportion of patients who experienced, at least once, one treatment-emergent adverse reaction of the type listed. A reaction was considered treatment-emergent if it occurred for the first time or worsened while receiving therapy following baseline evaluation. Adverse Reactions in Adults Adult Clinical Trial Database The data described below reflect exposure to duloxetine in placebo-controlled adult trials for MDD (N=3779), GAD (N=1018), OA (N=503), CLBP (N=600), DPNP (N=906), and FM (N=1294). The age range in this pooled population was 17 to 89 years of age. In this pooled population, 66%, 61%, 61%, 43%, and 94% of adult patients were female; and 82%, 73%, 85%, 74%, and 86% of adult patients were Caucasian in the MDD, GAD, OA and CLBP, DPNP, and FM populations, respectively. Most patients received Duloxetine delayed-release capsules dosages of a total of 60 to 120 mg per day [see Clinical Studies (14) ] . The data below do not include results of the trial that evaluated the efficacy of Duloxetine delayed-release capsules for the treatment of GAD in patients ≥65 years old (Study GAD-5) [see Clinical Studies (14.3) ] ; however, the adverse reactions observed in this geriatric population were generally similar to adverse reactions in the overall adult population. Adverse Reactions Leading to Treatment Discontinuation in Adult Placebo-Controlled Trials Major Depressive Disorder Approximately 8.4% (319/3779) of duloxetine-treated patients in placebo-controlled adult trials for MDD discontinued treatment due to an adverse reaction, compared with 4.6% (117/2536) of placebo-treated patients. Nausea (Duloxetine 1.1%, placebo 0.4%) was the only adverse reaction reported as a reason for discontinuation and considered to be drug-related (i.e., discontinuation occurring in at least 1% of the duloxetine-treated patients and at a rate of at least twice that of placebo-treated patients). Generalized Anxiety Disorder Approximately 13.7% (139/1018) of the duloxetine-treated patients in placebo-controlled adult trials for GAD discontinued treatment due to an adverse reaction, compared with 5% (38/767) for placebo-treated patients. Common adverse reactions reported as a reason for discontinuation and considered to be drug-related (as defined above) included nausea (Duloxetine 3.3%, placebo 0.4%), and dizziness (Duloxetine 1.3%, placebo 0.4%). Diabetic Peripheral Neuropathic Pain Approximately 12.9% (117/906) of the duloxetine-treated patients in placebo-controlled adult trials for DPNP discontinued treatment due to an adverse reaction, compared with 5.1% (23/448) for placebo-treated patients. Common adverse reactions reported as a reason for discontinuation and considered to be drug-related (as defined above) included nausea (Duloxetine 3.5%, placebo 0.7%), dizziness (Duloxetine 1.2%, placebo 0.4%), and somnolence (Duloxetine 1.1%, placebo 0%). Fibromyalgia Approximately 17.5% (227/1294) of the duloxetine-treated patients in 3- to 6-month placebo-controlled adult trials for FM discontinued treatment due to an adverse reaction, compared wit

7 DRUG INTERACTIONS Both CYP1A2 and CYP2D6 are responsible for duloxetine metabolism. Potent inhibitors of CYP1A2 should be avoided ( 7.1 ) Potent inhibitors of CYP2D6 may increase Duloxetine delayed-release capsules concentrations ( 7.2 ) Duloxetine delayed-release capsules is a moderate inhibitor of CYP2D6 ( 7.9 ) 7.1 Inhibitors of CYP1A2 When duloxetine 60 mg was co-administered with fluvoxamine 100 mg, a potent CYP1A2 inhibitor, to male subjects (n=14) duloxetine AUC was increased approximately 6-fold, the C max was increased about 2.5-fold, and duloxetine t 1/2 was increased approximately 3-fold. Other drugs that inhibit CYP1A2 metabolism include cimetidine and quinolone antimicrobials such as ciprofloxacin and enoxacin [see Warnings and Precautions (5.12) ]. 7.2 Inhibitors of CYP2D6 Concomitant use of duloxetine (40 mg once daily) with paroxetine (20 mg once daily) increased the concentration of duloxetine AUC by about 60%, and greater degrees of inhibition are expected with higher doses of paroxetine. Similar effects would be expected with other potent CYP2D6 inhibitors (e.g., fluoxetine, quinidine) [see Warnings and Precautions (5.12) ]. 7.3 Dual Inhibition of CYP1A2 and CYP2D6 Concomitant administration of duloxetine 40 mg twice daily with fluvoxamine 100 mg, a potent CYP1A2 inhibitor, to CYP2D6 poor metabolizer subjects (n=14) resulted in a 6-fold increase in duloxetine AUC and C max. 7.4 Drugs that Interfere with Hemostasis (e.g., NSAIDs, Aspirin, and Warfarin) Serotonin release by platelets plays an important role in hemostasis. Epidemiological studies of the case-control and cohort design that have demonstrated an association between use of psychotropic drugs that interfere with serotonin reuptake and the occurrence of upper gastrointestinal bleeding have also shown that concurrent use of an NSAID or aspirin may potentiate this risk of bleeding. Altered anticoagulant effects, including increased bleeding, have been reported when SSRIs or SNRIs are co-administered with warfarin. Concomitant administration of warfarin (2-9 mg once daily) under steady state conditions with Duloxetine delayed-release capsules 60 or 120 mg once daily for up to 14 days in healthy subjects (n=15) did not significantly change INR from baseline (mean INR changes ranged from 0.05 to +0.07). The total warfarin (protein bound plus free drug) pharmacokinetics (AUC τ,ss , C max,ss or t max,ss ) for both R- and S-warfarin were not altered by duloxetine. Because of the potential effect of duloxetine on platelets, patients receiving warfarin therapy should be carefully monitored when Duloxetine delayed-release capsules are initiated or discontinued [see Warnings and Precautions (5.5) ]. 7.5 Lorazepam Under steady-state conditions for duloxetine (60 mg Q 12 hours) and lorazepam (2 mg Q 12 hours), the pharmacokinetics of duloxetine were not affected by co-administration. 7.6 Temazepam Under steady-state conditions for duloxetine (20 mg qhs) and temazepam (30 mg qhs), the pharmacokinetics of duloxetine were not affected by co-administration. 7.7 Drugs that Affect Gastric Acidity Duloxetine delayed-release capsules have an enteric coating that resists dissolution until reaching a segment of the gastrointestinal tract where the pH exceeds 5.5. In extremely acidic conditions, Duloxetine delayed-release capsules, unprotected by the enteric coating, may undergo hydrolysis to form naphthol. Caution is advised in using Duloxetine delayed-release capsules in patients with conditions that may slow gastric emptying (e.g., some diabetics). Drugs that raise the gastrointestinal pH may lead to an earlier release of duloxetine. However, co- administration of Duloxetine delayed-release capsules with aluminum- and magnesium-containing antacids (51 mEq) or Duloxetine delayed-release capsules with famotidine, had no significant effect on the rate or extent of duloxetine absorption after administration of a 40 mg oral dose. It is unknown whether the concomitant administration of proton pump inhibitors affects duloxetine absorption [see Warnings and Precautions (5.14) ]. 7.8 Drugs Metabolized by CYP1A2 In vitro drug interaction studies demonstrate that duloxetine does not induce CYP1A2 activity. Therefore, an increase in the metabolism of CYP1A2 substrates (e.g., theophylline, caffeine) resulting from induction is not anticipated, although clinical studies of induction have not been performed. Duloxetine is an inhibitor of the CYP1A2 isoform in in vitro studies, and in two clinical studies the average (90% confidence interval) increase in theophylline AUC was 7% (1%-15%) and 20% (13%-27%) when co-administered with duloxetine (60 mg twice daily). 7.9 Drugs Metabolized by CYP2D6 Duloxetine is a moderate inhibitor of CYP2D6. When duloxetine was administered (at a dose of 60 mg twice daily) in conjunction with a single 50 mg dose of desipramine, a CYP2D6 substrate, the AUC of desipramine increased 3-fold [see Warnings and Precautions (5.12) ]. 7.10 Drugs