Buprenorphine

12.1 Mechanism of Action Buprenorphine sublingual tablet contains buprenorphine, a partial agonist at the mu-opioid receptor and an antagonist at the kappa-opioid receptor.

1 INDICATIONS AND USAGE Buprenorphine sublingual tablet is indicated for the treatment of opioid dependence and is preferred for induction. Buprenorphine sublingual tablet should be used as part of a complete treatment plan to include counseling and psychosocial support. Buprenorphine sublingual tablet, contains buprenorphine, a partial opioid agonist, and is indicated for the treatment of opioid dependence and is preferred for induction. (1) Buprenorphine sublingual tablet should be used as part of a complete treatment plan that includes counseling and psychosocial support. (1)

2 DOSAGE AND ADMINISTRATION Administer buprenorphine sublingual tablet sublingually as a single daily dose. (2.1) Strongly consider prescribing naloxone at the time buprenorphine sublingual tablet is initiated or renewed because patients being treated for opioid use disorder have the potential for relapse, putting them at risk for opioid overdose. (2.2) To avoid precipitating withdrawal, induction with buprenorphine sublingual tablet should be undertaken when objective and clear signs of withdrawal are evident. (2.3) Buprenorphine and naloxone sublingual film or buprenorphine and naloxone sublingual tablet is generally initiated after two days of buprenorphine sublingual tablet titration. (2.4) Administer buprenorphine sublingual tablets as directed in the Full Prescribing Information. (2.3, 2.4, 2.5) Buprenorphine sublingual tablet must be administered whole. Do not cut, chew, or swallow buprenorphine sublingual tablets. (2.5) When discontinuing treatment, gradually taper to avoid signs and symptoms of withdrawal. (2.9) 2.1 Important Dosage and Administration Instructions Buprenorphine sublingual tablet is administered sublingually as a single daily dose. Buprenorphine sublingual tablet does not contain naloxone and is preferred for use only during induction. Following induction, buprenorphine and naloxone sublingual film or buprenorphine and naloxone sublingual tablet is preferred due to the presence of naloxone when clinical use includes unsupervised administration. The use of buprenorphine sublingual tablet for unsupervised administration should be limited to those patients who cannot tolerate buprenorphine and naloxone sublingual film or buprenorphine and naloxone sublingual tablet; for example, those patients who have been shown to be hypersensitive to naloxone. Medication should be prescribed in consideration of the frequency of visits. Provision of multiple refills is not advised early in treatment or without appropriate patient follow-up visits. 2.2 Patient Access to Naloxone for the Emergency Treatment of Opioid Overdose Discuss the availability of naloxone for the emergency treatment of opioid overdose with the patient and caregiver. Because patients being treated for opioid use disorder have the potential for relapse, putting them at risk for opioid overdose, strongly consider prescribing naloxone for the emergency treatment of opioid overdose, both when initiating and renewing treatment with buprenorphine sublingual tablet. Also consider prescribing naloxone if the patient has household members (including children) or other close contacts at risk for accidental ingestion or opioid overdose [see Warnings and Precautions (5.2)]. Advise patients and caregivers that naloxone may also be administered for a known or suspected overdose with buprenorphine sublingual tablet itself. Higher than normal doses and repeated administration of naloxone may be necessary due to the long duration of action of buprenorphine sublingual tablet and its affinity for the mu-opioid receptor [see Overdosage (10)]. Inform patients and caregivers of their options for obtaining naloxone as permitted by individual state naloxone dispensing and prescribing requirements or guidelines (e.g., by prescription, directly from a pharmacist, or as part of a community-based program) [see Patient Counseling Information (17)]. 2.3 Induction Prior to induction, consideration should be given to the type of opioid dependence (i.e., long- or short-acting opioid products), the time since last opioid use, and the degree or level of opioid dependence. Patients dependent on heroin or other short-acting opioid products: At treatment initiation, the first dose of buprenorphine sublingual tablet should be administered only when objective and clear signs of moderate opioid withdrawal appear, and not less than 4 hours after the patient last used an opioid. It is recommended that an adequate treatment dose, titrated to clinical effectiveness, should be achieved as rapidly as possible. The dosing on the initial day of treatment may be given in 2 mg to 4 mg increments if preferred. In some studies, gradual induction over several days led to a high rate of dropout of buprenorphine patients during the induction period. In a one-month study, patients received 8 mg of buprenorphine sublingual tablet on Day 1 and 16 mg buprenorphine sublingual tablet on Day 2. From Day 3 onward, patients received either buprenorphine and naloxone sublingual tablet or buprenorphine sublingual tablet at the same buprenorphine dose as Day 2 based on their assigned treatment. Induction in the studies of buprenorphine solution was accomplished over 3 to 4 days, depending on the target dose. Patients dependent on methadone or other long-acting opioid products: Patients dependent upon methadone or other long-acting opioid products may be more susceptible to precipitated and prolonged withdrawal during induction than those on short-acting opioid products; therefore, the first dose

6 ADVERSE REACTIONS The following serious adverse reactions are described elsewhere in the labeling: • Addiction, Abuse, and Misuse [see Warnings and Precautions (5.1)] • Respiratory and CNS Depression [see Warnings and Precautions (5.2, 5.3)] • Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions (5.5)] • Adrenal Insufficiency [see Warnings and Precautions (5.6)] • Opioid Withdrawal [see Warnings and Precautions (5.7, 5.10)] • Hepatitis, Hepatic Events [see Warnings and Precautions (5.8)] • Hypersensitivity Reactions [see Warnings and Precautions (5.9)] • Orthostatic Hypotension [see Warnings and Precautions (5.16)] • Elevation of Cerebrospinal Fluid Pressure [see Warnings and Precautions (5.17)] • Elevation of Intracholedochal Pressure [see Warnings and Precautions (5.18)] Adverse events commonly observed with administration of buprenorphine are oral hypoesthesia, glossodynia, oral mucosal erythema, headache, nausea, vomiting, hyperhidrosis, constipation, signs and symptoms of withdrawal, insomnia, pain, and peripheral edema. ( 6 )To report SUSPECTED ADVERSE REACTIONS, contact Sun Pharmaceutical Industries, Inc. at 1-800-818-4555 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 safety of buprenorphine sublingual tablet was supported by clinical trials using buprenorphine sublingual tablet, buprenorphine and naloxone sublingual tablet and other trials using buprenorphine sublingual solutions. In total, safety data were available from 3214 opioid-dependent subjects exposed to buprenorphine at doses in the range used in treatment of opioid addiction. Few differences in adverse event profile were noted between buprenorphine sublingual tablet or buprenorphine administered as a sublingual solution. The following adverse events were reported to occur by at least 5% of patients in a 4-week study (Table 1). Table 1. Adverse Events ≥ 5% by Body System and Treatment Group in a 4-week study N(%) N(%) Body System / Adverse Event (COSTART Terminology) Buprenorphine Sublingual Tablets 16 mg/day N = 103 Placebo N = 107 Body as a Whole Asthenia 5 (4.9%) 7 (6.5%) Chills 8 (7.8%) 8 (7.5%) Headache 30 (29.1%) 24 (22.4%) Infection 12 (11.7%) 7 (6.5%) Pain 19 (18.4%) 20 (18.7%) Pain Abdomen 12 (11.7%) 7 (6.5%) Pain Back 8 (7.8%) 12 (11.2%) Withdrawal Syndrome 19 (18.4%) 40 (37.4%) Cardiovascular System Vasodilation 4 (3.9%) 7 (6.5%) Digestive System Constipation 8 (7.8%) 3 (2.8%) Diarrhea 5 (4.9%) 16 (15.0%) Nausea 14 (13.6%) 12 (11.2%) Vomiting 8 (7.8%) 5 (4.7%) Nervous System Insomnia 22 (21.4%) 17 (15.9%) Respiratory System Rhinitis 10 (9.7%) 14 (13.1%) Skin and Appendages Sweating 13 (12.6%) 11 (10.3%) The adverse event profile of buprenorphine was also characterized in the dose-controlled study of buprenorphine solution, over a range of doses in four months of treatment. Table 2 shows adverse events reported by at least 5% of subjects in any dose group in the dose-controlled study. Table 2. Adverse Events (≥ 5%) by Body System and Treatment Group in a 16-week Study Body System /Adverse Event (COSTART Terminology) Buprenorphine Dose* Very Low* (N=184) Low* (N=180) Moderate* (N=186) High* (N=181) Total* (N=731) N (%) N (%) N (%) N (%) N (%) Body as a Whole Abscess 9 (5%) 2 (1%) 3 (2%) 2 (1%) 16 (2%) Asthenia 26 (14%) 28 (16%) 26 (14%) 24 (13%) 104 (14%) Chills 11 (6%) 12 (7%) 9 (5%) 10 (6%) 42 (6%) Fever 7 (4%) 2 (1%) 2 (1%) 10 (6%) 21 (3%) Flu Syndrome 4 (2%) 13 (7%) 19 (10%) 8 (4%) 44 (6%) Headache 51 (28%) 62 (34%) 54 (29%) 53 (29%) 220 (30%) Infection 32 (17%) 39 (22%) 38 (20%) 40 (22%) 149 (20%) Injury Accidental 5 (3%) 10 (6%) 5 (3%) 5 (3%) 25 (3%) Pain 47 (26%) 37 (21%) 49 (26%) 44 (24%) 177 (24%) Pain Back 18 (10%) 29 (16%) 28 (15%) 27 (15%) 102 (14%) Withdrawal Syndrome 45 (24%) 40 (22%) 41 (22%) 36 (20%) 162 (22%) Digestive System Constipation 10 (5%) 23 (13%) 23 (12%) 26 (14%) 82 (11%) Diarrhea 19 (10%) 8 (4%) 9 (5%) 4 (2%) 40 (5%) Dyspepsia 6 (3%) 10 (6%) 4 (2%) 4 (2%) 24 (3%) Nausea 12 (7%) 22 (12%) 23 (12%) 18 (10%) 75 (10%) Vomiting 8 (4%) 6 (3%) 10 (5%) 14 (8%) 38 (5%) Nervous System Anxiety 22 (12%) 24 (13%) 20 (11%) 25 (14%) 91 (12%) Depression 24 (13%) 16 (9%) 25 (13%) 18 (10%) 83 (11%) Dizziness 4 (2%) 9 (5%) 7 (4%) 11 (6%) 31 (4%) Insomnia 42 (23%) 50 (28%) 43 (23%) 51 (28%) 186 (25%) Nervousness 12 (7%) 11 (6%) 10 (5%) 13 (7%) 46 (6%) Somnolence 5 (3%) 13 (7%) 9 (5%) 11 (6%) 38 (5%) Respiratory System Cough Increase 5 (3%) 11 (6%) 6 (3%) 4 (2%) 26 (4%) Pharyngitis 6 (3%) 7 (4%) 6 (3%) 9 (5%) 28 (4%) Rhinitis 27 (15%) 16 (9%) 15 (8%) 21 (12%) 79 (11%) Skin and Appendages Sweat 23 (13%) 21 (12%) 20 (11%) 23 (13%) 87 (12%) Special Senses Runny Eyes 13 (7%) 9 (5%) 6 (3%) 6 (3%) 34 (5%) *Sublingual

7 DRUG INTERACTIONS Table 3 includes clinically significant drug interactions with buprenorphine. Table 3. Clinically Significant Drug Interactions Benzodiazepines or other Central Nervous System (CNS) Depressants Clinical Impact: Due to additive pharmacologic effects, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, increases the risk of respiratory depression, profound sedation, coma, and death. Intervention: Cessation of benzodiazepines or other CNS depressants is preferred in most cases of concomitant use. In some cases, monitoring in a higher level of care for taper may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or CNS depressant or decreasing to the lowest effective dose may be appropriate. Before co-prescribing benzodiazepines for anxiety or insomnia, ensure that patients are appropriately diagnosed and consider alternative medications and non-pharmacologic treatments [see Warnings and Precautions (5.2, 5.3)]. If concomitant use is warranted, strongly consider prescribing naloxone for the emergency treatment of opioid overdose, as is recommended for all patients in treatment for opioid use disorder [see Warnings and Precautions (5.2)]. Examples: Alcohol, benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, and other opioids. Inhibitors of CYP3A4 Clinical Impact: The concomitant use of buprenorphine and CYP3A4 inhibitors can increase the plasma concentration of buprenorphine, resulting in increased or prolonged opioid effects, particularly when an inhibitor is added after a stable dose of buprenorphine is achieved. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the buprenorphine plasma concentration will decrease [see Clinical Pharmacology (12.3)] , potentially resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to buprenorphine. Intervention: If concomitant use is necessary, consider dosage reduction of buprenorphine until stable drug effects are achieved. Monitor patients for respiratory depression and sedation at frequent intervals. If a CYP3A4 inhibitor is discontinued, consider increasing the buprenorphine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of buprenorphine and CYP3A4 inducers can decrease the plasma concentration of buprenorphine [see Clinical Pharmacology (12.3)] , potentially resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to buprenorphine. After stopping a CYP3A4 inducer, as the effects of the inducer decline, the buprenorphine plasma concentration will increase [see Clinical Pharmacology (12.3)] , which could increase or prolong both therapeutic effects and adverse reactions and may cause serious respiratory depression. Intervention: If concomitant use is necessary, consider increasing the buprenorphine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. If a CYP3A4 inducer is discontinued, consider buprenorphine dosage reduction and monitor for signs of respiratory depression. Examples: Rifampin, carbamazepine, phenytoin Antiretrovirals: Non-nucleoside reverse transcriptase inhibitors (NNRTIs) Clinical Impact: Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are metabolized principally by CYP3A4. Efavirenz, nevirapine, and etravirine are known CYP3A inducers, whereas delavirdine is a CYP3A inhibitor. Significant pharmacokinetic interactions between NNRTIs (e.g., efavirenz and delavirdine) and buprenorphine have been shown in clinical studies, but these pharmacokinetic interactions did not result in any significant pharmacodynamic effects. Intervention: Patients who are on chronic buprenorphine treatment should have their dose monitored if NNRTIs are added to their treatment regimen. Examples: efavirenz, nevirapine, etravirine, delavirdine Antiretrovirals: Protease inhibitors (PIs) Clinical Impact: Studies have shown some antiretroviral protease inhibitors (PIs) with CYP3A4 inhibitory activity (nelfinavir, lopinavir/ritonavir, ritonavir) have little effect on buprenorphine pharmacokinetic and no significant pharmacodynamic effects. Other PIs with CYP3A4 inhibitory activity (atazanavir and atazanavir/ritonavir) resulted in elevated levels of buprenorphine and norbuprenorphine, and patients in one study reported increased sedation. Symptoms of opioid excess have been found in postmarketing reports of patients receiving buprenorphine and atazanavir with and without ritonavir concomitantly. Intervention: Monitor patients taking buprenorphine and atazanavir with and without ritonavir, and reduce dose of