Fentanyl Transdermal

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 contains fentanyl, an opioid agonist, and 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 )

Fentanyl transdermal systems are a rectangular, opaque patch with rounded corners: Fentanyl Transdermal System 12 mcg/hour* (system size 3.9 cm 2 ) is green in color. Fentanyl Transdermal System 25 mcg/hour (system size 7.8 cm 2 ) is green in color. Fentanyl Transdermal System 37.5 mcg/hour (system size 11.7 cm 2 ) is green in color. Fentanyl Transdermal System 50 mcg/hour (system size 15.6 cm 2 ) is green in color. Fentanyl Transdermal System 62.5 mcg/hour (system size 19.6 cm 2 ) is green in color. Fentanyl Transdermal System 75 mcg/hour (system size 23.4 cm 2 ) is green in color. Fentanyl Transdermal System 100 mcg/hour (system size 31.3 cm 2 ) is green in color. * This lowest strength is designated as 12 mcg/hour (however, the actual strength is 12.5 mcg/hour) to distinguish it from a possible 125 mcg/hr dosage that could be prescribed by using multiple transdermal systems. The 12 mcg/hour system has a green border and the 25, 37.5, 50, 62.5, 75 and 100 mcg/hour systems have green stripes that increase in number with each sequential increasing dosage strength. Transdermal System : 12 mcg/hour, 25 mcg/hour, 37.5 mcg/hour, 50 mcg/hour, 62.5 mcg/hour, 75 mcg/hour, 100 mcg/hour. ( 3 )

Fentanyl transdermal system is contraindicated in: patients who are not opioid-tolerant. the management of acute or intermittent pain, or in patients who require opioid analgesia for a short period of time. the management of post-operative pain, including use after out-patient or day surgeries, (e.g., tonsillectomies). the management of mild pain. patients with significant respiratory depression [see Warnings and Precautions (5.12) ] . in patients with acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see Warnings and Precautions (5.12) ] . in patients with known or suspected gastrointestinal obstruction, including paralytic ileus [see Warnings and Precautions (5.19) ] . in patients with hypersensitivity to fentanyl (e.g., anaphylaxis) or any components of the transdermal system [see Adverse Reactions (6.2) ] . Opioid non-tolerant patients. ( 4 ) Acute or intermittent pain, postoperative pain, mild pain. ( 4 ) Significant respiratory depression. ( 4 ) Acute or severe bronchial asthma in an unmonitored setting or in absence of resuscitative equipment. ( 4 ) Known or suspected gastrointestinal obstruction, including paralytic ileus. ( 4 ) Known hypersensitivity to fentanyl or any of the components of the transdermal system. ( 4 )

Risk of Increased Fentanyl Absorption with Elevated Body Temperature : Regularly evaluate patients with fever closely for sedation and respiratory depression and reduce the dose if necessary. Warn patients to avoid strenuous exertion that may lead to increased body temperature. ( 5.9 ) Opioid-Induced Hyperalgesia (OIH) and Allodynia : Opioid-Induced Hyperalgesia (OIH) occurs when an opioid analgesic paradoxically causes an increase in pain, or an increase in sensitivity to pain. If OIH is suspected, carefully consider appropriately decreasing the dose of the current opioid analgesic or opioid rotation. ( 5.10 ) Serotonin Syndrome with Concomitant Use of Serotonergic Drugs : Potentially life-threatening condition could result from concomitant serotonergic drug administration. Discontinue fentanyl transdermal system immediately if serotonin syndrome is suspected. ( 5.11 ) Life-Threatening Respiratory Depression in Patients with Chronic Pulmonary Disease or in Elderly, Cachectic, or Debilitated Patients : Regularly evaluate, particularly during initiation and titration. ( 5.12 ) Adrenal Insufficiency : If diagnosed, treat with physiologic replacement of corticosteroids, and wean patient off of the opioid. ( 5.13 ) Severe Hypotension : Regularly evaluate during dose initiation and titration. Avoid the use of fentanyl transdermal system in patients with circulatory shock. ( 5.14) Risks of Use in Patients with Increased Intracranial Pressure, Brain Tumors, Head Injury or Impaired Consciousness : Monitor for sedation and respiratory depression. Avoid use of fentanyl transdermal system in patients with impaired consciousness or coma. ( 5.15 )

5.1 Addiction, Abuse, and Misuse Fentanyl transdermal system contains fentanyl, an opioid agonist and a Schedule II controlled substance. As an opioid, fentanyl transdermal system exposes users to the risks of addiction, abuse, and misuse. Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed fentanyl transdermal system. Addiction can occur at recommended doses and if the drug is misused or abused. The risk of opioid-related overdose or overdose-related death is increased with higher opioid doses, and this risk persists over the course of therapy. In postmarketing studies, addiction, abuse, misuse, and fatal and non-fatal opioid overdose were observed in patients with long-term opioid use [see Adverse Reactions (6.2) ] . Assess each patient’s risk for opioid addiction, abuse, or misuse prior to prescribing fentanyl transdermal system, and reassess all patients receiving fentanyl transdermal system for the development of these behaviors and conditions. Risks are increased in patients with a personal or family history of substance abuse (including drug or alcohol abuse or addiction) or mental illness (e.g., major depression). The potential for these risks should not, however, prevent the proper management of pain in any given patient. Patients at increased risk may be prescribed opioids such as fentanyl transdermal system, but use in such patients necessitates intensive counseling about the risks and proper use of fentanyl transdermal system along with frequent reevaluation for signs of addiction, abuse, and misuse. Consider recommending or prescribing an opioid overdose reversal agent [see Dosage and Administration (2.2) , Warnings and Precautions (5.2) ] . Abuse or misuse of fentanyl transdermal system by placing it in the mouth, chewing it, swallowing it, or using it in ways other than indicated may cause choking, overdose, and death [see Overdosage (10) ] . Opioids are sought for nonmedical use and are subject to diversion from legitimate prescribed use. Consider these risks when prescribing or dispensing fentanyl transdermal system. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity and advising the patient on careful storage of the drug during the course of treatment and proper disposal of unused drug. Contact local state professional licensing board or state-controlled substances authority for information on how to prevent and detect abuse or diversion of this product.

5.2 Life-Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression has been reported with the use of opioids, even when used as recommended. Respiratory depression, if not immediately recognized and treated, may lead to respiratory arrest and death. Management of respiratory depression may include close observation, supportive measures, and use of opioid overdose reversal agents, depending on the patient’s clinical status [see Overdosage (10) ] . Carbon dioxide (CO 2 ) retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids. Fentanyl transdermal system is indicated only in opioid tolerant patients because of the risk for respiratory depression and death. While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of fentanyl transdermal system, the risk is greatest during the initiation of therapy or following a dosage increase. To reduce the risk of respiratory depression, proper dosing and titration of fentanyl transdermal system are essential [see Dosage and Administration (2) ] . Overestimating the fentanyl transdermal system dosage when converting patients from another opioid product can result in fatal overdose with the first dose. Accidental exposure to fentanyl transdermal system, especially in children, can result in respiratory depression and death due to an overdose of fentanyl. Educate patients and caregivers on how to recognize respiratory depression and emphasize the importance of calling 911 or getting emergency medical help right away in the event of a known or suspected overdose [see Patient Counseling Information (17) ] . Opioids can cause sleep-related breathing disorders including central sleep apnea (CSA) and sleep-related hypoxemia. Opioid use increases the risk of CSA in a dose-dependent fashion. In patients who present with CSA, consider decreasing the opioid dosage using best practices for opioid taper [see Dosage and Administration (2.9)] . Patient Access to an Opioid Overdose Reversal Agent for the Emergency Treatment of Opioid Overdose Inform patients and caregivers about opioid overdose reversal agents (e.g., naloxone, nalmefene). Discuss the importance of having access to an opioid overdose reversal agent, especially if the patient has risk factors for overdose (e.g., concomitant use of CNS depressants, a history of opioid use disorder, or prior opioid overdose) or if there are household members (including children) or other close contacts at risk for accidental ingestion or opioid overdose. The presence of risk factors for overdose should not prevent the management of pain in any patient [see Warnings and Precautions (5.1 , 5.4 )] . Discuss the options for obtaining an opioid overdose reversal agent (e.g., prescription, over-the-counter, or as part of a community-based program). There are important differences among the opioid overdose reversal agents, such as route of administration, product strength, approved patient age range, and pharmacokinetics. Be familiar with these differences, as outlined in the approved labeling for those products, prior to recommending or prescribing such an agent. Educate patients and caregivers on how to recognize respiratory depression, and how to use an opioid overdose reversal agent for the emergency treatment of opioid overdose. Emphasize the importance of calling 911 or getting emergency medical help, even if an opioid overdose reversal agent is administered [see Dosage and Administration (2.2) , Warnings and Precautions (5.1 , 5.4 ), Overdosage (10) ] .

5.3 Accidental Exposure A considerable amount of active fentanyl remains in fentanyl transdermal system even after use as directed. […]

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) ] Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions (5.5) ] Interactions with Benzodiazepines or Other Central Nervous System Depressants [see Warnings and Precautions (5.4) ] 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, contact Mallinckrodt at 1-800-778-7898 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 ClassAdverse 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 Postmarketing 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 Investigations : 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. […]

Table 6 includes clinically significant drug interactions with fentanyl transdermal system. Table 6. Clinically Significant Drug Interactions with Fentanyl Transdermal System Inhibitors of CYP3A4 Clinical Impact: The concomitant use of fentanyl transdermal system and CYP3A4 inhibitors can increase the plasma concentration of fentanyl, resulting in increased or prolonged opioid effects particularly when an inhibitor is added after a stable dose of fentanyl transdermal system is achieved [see Warnings and Precautions (5.7) ] . After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the fentanyl transdermal system plasma concentration will decrease [see Clinical Pharmacology (12.3 ) ] , resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to fentanyl. Intervention: If concomitant use is necessary, consider dosage reduction of fentanyl transdermal system until stable drug effects are achieved. Evaluate patients at frequent intervals for respiratory depression and sedation. If a CYP3A4 inhibitor is discontinued, consider increasing the fentanyl transdermal system dosage until stable drug effects are achieved. Evaluate for signs of opioid withdrawal. Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir), grapefruit juice CYP3A4 Inducers Clinical Impact: The concomitant use of fentanyl transdermal system and CYP3A4 inducers can decrease the plasma concentration of fentanyl [see Clinical Pharmacology (12.3) ] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to fentanyl [see Warnings and Precautions (5.7) ] . After stopping a CYP3A4 inducer, as the effects of the inducer decline, the fentanyl plasma concentration will increase [see Clinical Pharmacology (12.3) ] , which could increase or prolong both the therapeutic effects and adverse reactions, and may cause serious respiratory depression. Intervention: If concomitant use is necessary, consider increasing the fentanyl transdermal system dosage until stable drug effects are achieved. Evaluate for signs of opioid withdrawal. If a CYP3A4 inducer is discontinued, consider fentanyl transdermal system dosage reduction and evaluate patients at frequent intervals for signs of respiratory depression and sedation. Examples: Rifampin, carbamazepine, phenytoin Benzodiazepines and Other Central Nervous System (CNS) Depressants Clinical Impact: Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death. Intervention: Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Inform patients and caregivers of this potential interaction, educate them on the signs and symptoms of respiratory depression (including sedation). If concomitant use is warranted, consider recommending or prescribing an opioid overdose reversal agent [see Dosage and Administration (2.2) , Warnings and Precautions (5.1 , 5.2 , 5.4 )] . Examples: Benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids (gabapentin or pregabalin), other opioids, alcohol. Serotonergic Drugs Clinical Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome [see Warnings and Precautions (5.11) ]. Intervention: If concomitant use is warranted, frequently evaluate the patient, particularly during treatment initiation and dose adjustment. Discontinue fentanyl transdermal system if serotonin syndrome is suspected. Examples: Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue). Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact: MAOI interactions with opioids may manifest as serotonin syndrome [see Warnings and Precautions (5.11) ] or opioid toxicity (e.g., respiratory depression, coma). Intervention: The use of fentanyl transdermal system is not recommended for patients taking MAOIs or within 14 days of stopping such treatment. Examples: phenelzine, tranylcypromine, linezolid Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics Clinical Impact: May reduce the analgesic effect of fentanyl transdermal system and/or precipitate withdrawal symptoms. Intervention: Avoid concomitant use. Examples: butorphanol, nalbuphine, pentazocine, buprenorphine Muscle Relaxants Clinical Impact: Fentanyl transdermal system may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Intervention: Because respiratory depression may be greater than otherwise expected, decrease the dosage of fentanyl transdermal system and/or the muscle relaxant as necessary. Due to the risk of respiratory depression with concomitant use of skeletal muscle relaxants and opioids, consider recommending or prescribing an opioid overdose reversal agent [see Dosage and Administration (2.2) , Warnings and Precautions (5.2 , 5.4) ] . Examples: cyclobenzaprine, metaxalone Diuretics Clinical Impact: Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Intervention: Evaluate patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. Anticholinergic Drugs Clinical Impact: The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Intervention: Evaluate patients for signs of urinary retention or reduced gastric motility when fentanyl transdermal system is used concomitantly with anticholinergic drugs. Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics : Avoid use with fentanyl transdermal system because they may reduce analgesic effect of fentanyl transdermal system or precipitate withdrawal symptoms. ( 5.21 , 7 )

Pregnancy : May cause fetal harm. ( 8.1 ) Lactation : Not recommended. ( 8.2 ) Severe Hepatic and Renal Impairment : Use not recommended. ( 8.6 , 8.7 )

8.1 Pregnancy Risk Summary Use of opioid analgesics for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome [see Warnings and Precautions (5.5) ] . Available data with fentanyl transdermal system in pregnant women are insufficient to inform a drug-associated risk for major birth defects and miscarriage. In animal reproduction studies, fentanyl administration to pregnant rats during organogenesis was embryocidal at doses within the range of the human recommended dosing. When administered during gestation through lactation fentanyl administration to pregnant rats resulted in reduced pup survival and developmental delays at doses within the range of the human recommended dosing. No evidence of malformations were noted in animal studies completed to date [see Data] . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Use of opioid analgesics for an extended period of time during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. Neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. Observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly [see Warnings and Precautions (5.5) ] . Labor or Delivery Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid overdose reversal agent, such as naloxone or nalmefene, must be available for reversal of opioid-induced respiratory depression in the neonate. Fentanyl transdermal system is not recommended for use in pregnant women during or immediately prior to labor, when use of shorter-acting analgesics or other analgesic techniques are more appropriate. Opioid analgesics, including fentanyl transdermal system, can prolong labor through actions that temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilatation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Data Human Data There are no adequate and well-controlled studies in pregnant women. Fentanyl transdermal system should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Chronic maternal treatment with fentanyl during pregnancy has been associated with transient respiratory depression, behavioral changes, or seizures characteristic of neonatal abstinence syndrome in newborn infants. Symptoms of neonatal respiratory or neurological depression were no more frequent than expected in most studies of infants born to women treated acutely during labor with intravenous or epidural fentanyl. Transient neonatal muscular rigidity has been observed in infants whose mothers were treated with intravenous fentanyl. Animal Data No evidence of malformations or adverse effects on the fetus was reported in a published study in which pregnant rats were administered fentanyl continuously via subcutaneously implanted osmotic minipumps at doses of 10, 100, or 500 mcg/kg/day starting 2 weeks prior to breeding and throughout pregnancy. The high dose was approximately 2 times the daily human dose administered by a 100 mcg/hr patch on a mg/m 2 basis). In contrast, the intravenous administration of fentanyl (0, 0.01, or 0.03 mg/kg) to pregnant rats from Gestation Day 6 to 18 suggested evidence of embryo-toxicity and a slight increase in mean delivery time in the 0.03 mg/kg/day group (0.1 times the human dose administered by a 100 mcg/hr patch on a mg/m 2 basis). There was no clear evidence of teratogenicity noted. Pregnant female New Zealand White rabbits were treated with fentanyl (0, 0.025, 0.1, 0.4 mg/kg) via intravenous infusion from day 6 to day 18 of pregnancy. Fentanyl produced a slight decrease in the body weight of the live fetuses at the high dose, which may be attributed to maternal toxicity. Under the conditions of the assay, there was no evidence for fentanyl induced adverse effects on embryo-fetal development at doses up to 0.4 mg/kg (approximately 3 times the daily human dose administered by a 100 mcg/hr patch on a mg/m 2 basis). The potential effects of fentanyl on prenatal and postnatal development were examined in the rat model. Female Wistar rats were treated with 0, 0.025, 0.1, or 0.4 mg/kg/day fentanyl via intravenous infusion from day 6 of pregnancy through 3 weeks of lactation. Fentanyl treatment (0.4 mg/kg/day) significantly decreased body weight in male and female pups and also decreased survival in pups at day 4. Both the mid-dose and high-dose of fentanyl animals demonstrated alterations in some physical landmarks of development (delayed incisor eruption and eye opening) and transient behavioral development (decreased locomotor activity at day 28 which recovered by day 50). The mid-dose and the high-dose are 0.4 and 1.6 times the daily human dose administered by a 100 mcg/hr patch on a mg/m 2 basis.

8.2 Lactation Risk Summary Fentanyl is excreted in human milk; therefore, fentanyl transdermal system is not recommended for use in nursing women because of the possibility of effects in their infants. Because of the potential for serious adverse reactions, including excess sedation and respiratory depression in a breastfed infant, advise patients that breastfeeding is not recommended during treatment with fentanyl transdermal system. Clinical Considerations Monitor infants exposed to fentanyl transdermal system through breast milk for excess sedation and respiratory depression. Withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid analgesic is stopped, or when breast-feeding is stopped.

8.3 Females and Males of Reproductive Potential Infertility Use of opioids for an extended period of time may cause reduced fertility in females and males of reproductive potential. It is not known whether these effects on fertility are reversible [see Adverse Reactions (6.2) , Clinical Pharmacology (12.2) and Nonclinical Toxicology (13.1) ] .

8.4 Pediatric Use 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. Starting doses of 25 mcg/hr and higher were used by 181 patients who had been on prior daily opioid doses of at least 45 mg/day of oral morphine or an equianalgesic dose of another opioid. Initiation of fentanyl transdermal system therapy in pediatric patients taking less than 60 mg/day of oral morphine or an equianalgesic dose of another opioid has not been evaluated in controlled clinical trials. The safety and effectiveness of fentanyl transdermal system in children under 2 years of age have not been established. […]

Fentanyl is an opioid agonist. Fentanyl interacts predominately with the opioid mu-receptor. These mu-binding sites are distributed in the human brain, spinal cord, and other tissues.