1 INDICATIONS AND USAGE Fentanyl transdermal system is indicated for the management of severe and persistent pain in opioid-tolerant patients, that requires an opioid analgesic and that cannot be adequately treated with alternative options, including immediate-release opioids.

Patients considered opioid-tolerant are those who are taking, for one week or longer, at least 60 mg morphine per day, 25 mcg transdermal fentanyl per hour, 30 mg oral oxycodone per day, 8 mg oral hydromorphone per day, 25 mg oral oxymorphone per day, 60 mg oral hydrocodone per day, or an equianalgesic dose of another opioid.

Limitations of Use: Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosage or duration and persist over the course of therapy [see Warnings and Precautions ( 5.1 )] , reserve opioid analgesics, including fentanyl transdermal system for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain.

Fentanyl transdermal system is not indicated as an as-needed (prn) analgesic.

Fentanyl transdermal system, an opioid agonist, is indicated for the management of severe and persistent pain in opioid-tolerant patients, that requires an opioid analgesic and that cannot be adequately treated with alternative options, including immediate-release opioids.

( 1 ) Patients considered opioid-tolerant are those taking, for one week or longer, at least 60 mg oral morphine per day, 25 mcg transdermal fentanyl per hour, 30 mg oral oxycodone per day, 8 mg oral hydromorphone per day, 25 mg oral oxymorphone per day, 60 mg oral hydrocodone per day or an equianalgesic dose of another opioid.

( 2.1 ) Limitations of use: Because of the risks of addiction, abuse, misuse, overdose and death, which can occur at any dosage or duration and persist over the course of therapy, reserve opioid analgesics, including fentanyl transdermal system for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain.

( 1 , 5.1 ) Fentanyl transdermal system is not indicated as an as-needed (prn) analgesic.

( 1 )

6 ADVERSE REACTIONS The following serious adverse reactions are discussed elsewhere in the labeling: Addiction, Abuse, and Misuse [see Warnings and Precautions ( 5.1 )] Life-Threatening Respiratory Depression [see Warnings and Precautions ( 5.2 )] Accidental Exposure [see Warnings and Precautions ( 5.3 )] Interactions with Benzodiazepines or Other Central Nervous System Depressants [see Warnings and Precautions ( 5.4 )] Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions ( 5.5 )] Opioid-Induced Hyperalgesia and Allodynia [see Warnings and Precautions ( 5.10 )] Serotonin Syndrome [see Warnings and Precautions ( 5.11 )] Adrenal Insufficiency [see Warnings and Precautions ( 5.13 )] Severe Hypotension [see Warnings and Precautions ( 5.14 )] Gastrointestinal Adverse Reactions [see Warnings and Precautions ( 5.19 )] Seizures [see Warnings and Precautions ( 5.20 )] Withdrawal [see Warnings and Precautions ( 5.21 )] Most common adverse reactions (≥5%) are nausea, vomiting, somnolence, dizziness, insomnia, constipation, hyperhidrosis, fatigue, feeling cold, anorexia, headache, and diarrhea.

( 6 .) To report SUSPECTED ADVERSE REACTIONS, call Ingenus Pharmaceuticals, LLC at 1-877-748-1970 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1 Clinical Trial 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 clinical practice.

The safety of fentanyl transdermal system was evaluated in 216 patients who took at least one dose of fentanyl transdermal system in a multicenter, double-blind, randomized, placebo-controlled clinical trial of fentanyl transdermal system.

This trial examined patients over 40 years of age with severe pain induced by osteoarthritis of the hip or knee and who were in need of and waiting for joint replacement.

The most common adverse reactions (≥5%) in a double-blind, randomized, placebo-controlled clinical trial in patients with severe pain were nausea, vomiting, somnolence, dizziness, insomnia, constipation, hyperhidrosis, fatigue, feeling cold, and anorexia.

Other common adverse reactions (≥5%) reported in clinical trials in patients with chronic malignant or nonmalignant pain were headache and diarrhea.

Adverse reactions reported for ≥1% of fentanyl transdermal system-treated patients and with an incidence greater than placebo-treated patients are shown in Table 3.

The most common adverse reactions that were associated with discontinuation in patients with pain (causing discontinuation in ≥1% of patients) were depression, dizziness, somnolence, headache, nausea, vomiting, constipation, hyperhidrosis, and fatigue.

Table 3: Adverse Reactions Reported by ≥1% of Fentanyl Transdermal System-treated Patients and With an Incidence Greater Than Placebo-treated Patients in 1 Double-Blind, Placebo-Controlled Clinical Trial of Fentanyl Transdermal System System/Organ Class Adverse Reaction Fentanyl Transdermal System % (N=216) Placebo % (N=200) Cardiac disorders Palpitations 4 1 Ear and labyrinth disorders Vertigo 2 1 Gastrointestinal disorders Nausea 41 17 Vomiting 26 3 Constipation 9 1 Abdominal pain upper 3 2 Dry mouth 2 0 General disorders and administration site conditions Fatigue 6 3 Feeling cold 6 2 Malaise 4 1 Asthenia 2 0 Edema peripheral 1 1 Metabolism and nutrition disorders Anorexia 5 0 Musculoskeletal and connective tissue disorders Muscle spasms 4 2 Nervous system disorders Somnolence 19 3 Dizziness 10 4 Psychiatric disorders Insomnia 10 7 Depression 1 0 Skin and subcutaneous tissue disorders Hyperhidrosis 6 1 Pruritus 3 2 Rash 2 1 Adverse reactions not reported in Table 3 that were reported by ≥1% of fentanyl transdermal system-treated adult and pediatric patients (N=1854) in 11 controlled and uncontrolled clinical trials of fentanyl transdermal system used for the treatment of chronic malignant or nonmalignant pain are shown in Table 4.

Table 4: Adverse Reactions Reported by ≥1% of Fentanyl Transdermal System-treated Patients in 11 Clinical Trials of Fentanyl Transdermal System System/Organ Class Adverse Reaction Fentanyl Transdermal System % (N=1854) Gastrointestinal disorders Diarrhea 10 Abdominal pain 3 Immune system disorders Hypersensitivity 1 Nervous system disorders Headache 12 Tremor 3 Paresthesia 2 Psychiatric disorders Anxiety 3 Confusional state 2 Hallucination 1 Renal and urinary disorders Urinary retention 1 Skin and subcutaneous tissue disorders Erythema 1 The following adverse reactions occurred in adult and pediatric patients with an overall frequency of <1% and are listed in descending frequency within each System/Organ Class: Cardiac disorders: cyanosis Eye disorders: miosis Gastrointestinal disorders: subileus General disorders and administration site conditions: application site reaction, influenza-like illness, application site hypersensitivity, drug withdrawal syndrome, application site dermatitis Musculoskeletal and connective tissue disorders: muscle twitching Nervous system disorders: hypoesthesia Psychiatric disorders: disorientation, euphoric mood Reproductive system and breast disorders: erectile dysfunction, sexual dysfunction Respiratory, thoracic and mediastinal disorders: respiratory depression Skin and subcutaneous tissue disorders: eczema, dermatitis allergic, dermatitis contact Pediatrics The safety of fentanyl transdermal system was evaluated in three open-label trials in 289 pediatric patients with chronic pain, 2 years of age through 18 years of age.

Adverse reactions reported by ≥1% of fentanyl transdermal system-treated pediatric patients are shown in Table 5.

Table 5: Adverse Reactions Reported by ≥1% of Fentanyl Transdermal System-treated Pediatric Patients in 3 Clinical Trials of Fentanyl Transdermal System System/Organ Class Adverse Reaction Fentanyl Transdermal System % (N=289) Gastrointestinal disorders Vomiting 34 Nausea 24 Constipation 13 Diarrhea 13 Abdominal pain 9 Abdominal pain upper 4 Dry mouth 2 General disorders and administration site conditions Edema peripheral 5 Fatigue 2 Application site reaction 1 Asthenia 1 Immune system disorders Hypersensitivity 3 Metabolism and nutrition disorders Anorexia 4 Musculoskeletal and connective tissue disorders Muscle spasms 2 Nervous system disorders Headache 16 Somnolence 5 Dizziness 2 Tremor 2 Hypoesthesia 1 Psychiatric disorders Insomnia 6 Anxiety 4 Depression 2 Hallucination 2 Renal and urinary disorders Urinary retention 3 Respiratory, thoracic and mediastinal disorders Respiratory depression 1 Skin and subcutaneous tissue disorders Pruritus 13 Rash 6 Hyperhidrosis 3 Erythema 3 6.2 Post-Marketing Experience The following adverse reactions have been identified during post-approval use of fentanyl transdermal system.

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.

Cardiac Disorders: tachycardia, bradycardia Eye Disorders: vision blurred Gastrointestinal Disorders: ileus, dyspepsia General Disorders and Administration Site Conditions: pyrexia, application site erosion and application site ulcer I nvestigations: weight decreased Nervous System Disorders : convulsions (including clonic convulsions and grand mal convulsion), amnesia, depressed level of consciousness, loss of consciousness Psychiatric Disorders : agitation Respiratory, Thoracic, and Mediastinal Disorders: respiratory distress, apnea, bradypnea, hypoventilation, dyspnea Vascular Disorders: hypotension, hypertension Serotonin syndrome: Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs.

Adrenal insufficiency: Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use.

Anaphylaxis: Anaphylaxis, including anaphylactic shock, has been reported with ingredients contained in fentanyl transdermal system.

Androgen deficiency: Cases of androgen deficiency have occurred with use of opioids for an extended period of time.

[see Clinical Pharmacology ( 12.2 )] .

Hyperalgesia and Allodynia: Cases of hyperalgesia and allodynia have been reported with opioid therapy of any duration [see Warnings and Precautions ( 5.10 )] Hypoglycemia: Cases of hypoglycemia have been reported in patients taking opioids.

Most reports were in patients with at least one predisposing risk factor (e.g., diabetes).

Opioid-induced esophageal dysfunction (OIED): Cases of OIED have been reported in patients taking opioids, and may occur more frequently in patients taking higher doses of opioids, and/or in patients taking opioids longer term [see Warnings and Precautions ( 5.19 )] .

Adverse Reactions from Observational Studies A prospective, observational cohort study estimated the risks of addiction, abuse, and misuse in patients initiating long-term use of Schedule II opioid analgesics between 2017 and 2021.

Study participants included in one or more analyses had been enrolled in selected insurance plans or health systems for at least one year, were free of at least one outcome at baseline, completed a minimum number of follow-up assessments, and either: 1) filled multiple extended-release/long-acting opioid analgesic prescriptions during a 90-day period (n=978); or 2) filled any Schedule II opioid analgesic prescriptions covering at least 70 of 90 days (n=1,244).

Those included also had no dispensing of the qualifying opioids in the previous 6 months.

Over 12 months: approximately 1% to 6% of participants across the two cohorts newly met criteria for addiction, as assessed with two validated interview-based measures of moderate-to-severe opioid use disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, and approximately 9% and 22% of participants across the two cohorts newly met criteria for prescription opioid abuse and misuse [defined in Drug Abuse and Dependence ( 9.2 )] , respectively, as measured with a validated self-reported instrument.

A retrospective, observational cohort study estimated the risk of opioid-involved overdose or opioid overdose-related death in patients with new long-term use of Schedule II opioid analgesics from 2006 through 2016 (n=220,249).

Included patients had been enrolled in either one of two commercial insurance programs, one managed care program, or one Medicaid program for at least 9 months.

New long-term use was defined as having Schedule II opioid analgesic prescriptions covering at least 70 days’ supply over the 3 months prior to study entry and none during the preceding 6 months.

Patients were excluded if they had an opioid-involved overdose in the 9 months prior to study entry.

Overdose was measured using a validated medical code-based algorithm with linkage to the National Death Index database.

The 5-year cumulative incidence estimates for opioid-involved overdose or opioid overdose-related death ranged from approximately 1.5% to 4% across study sites, counting only the first event during follow-up.

Approximately 17% of first opioid overdoses observed over the entire study period (5 years to 11 years, depending on the study site) were fatal.

Higher baseline opioid dose was the strongest and most consistent predictor of opioid-involved overdose or opioid overdose-related death.

Study exclusion criteria may have selected patients at lower risk of overdose, and substantial loss to follow-up (approximately 80%) also may have biased estimates.

The risk estimates from the studies described above may not be generalizable to all patients receiving opioid analgesics, such as those with exposures shorter or longer than the duration evaluated in the studies.