Fentanyl Citrate

6 ADVERSE REACTIONS The following serious adverse reactions are described, or described in greater detail, in other sections: Addiction, Abuse, and Misuse [see Warnings and Precautions (5.1) ] Life-Threatening Respiratory Depression [see Warnings and Precautions (5.2) ] Interactions with Benzodiazepines and Other CNS Depressants [see Warnings and Precautions (5.4) ] Severe Cardiovascular Depression [see Warnings and Precautions (5.6) ] Serotonin Syndrome [see Warnings and Precautions (5.7) ] Gastrointestinal Adverse Reactions [see Warnings and Precautions (5.10) ] Seizures [see Warnings and Precautions (5.11) ] The following adverse reactions associated with the use of fentanyl were identified in clinical studies or postmarketing reports. Because some of these reactions were 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. As with other opioid agonists, the most common serious adverse reactions reported to occur with fentanyl are respiratory depression, apnea, rigidity and bradycardia; if these remain untreated, respiratory arrest, circulatory depression or cardiac arrest could occur. Other adverse reactions that have been reported are hypertension, hypotension, dizziness, blurred vision, nausea, emesis, laryngospasm, diaphoresis, serotonin syndrome, adrenal insufficiency, and anaphylaxis. It has been reported that secondary rebound respiratory depression may occasionally occur postoperatively. When a tranquilizer is used with Fentanyl Citrate Injection, the following adverse reactions can occur: chills and/or shivering, restlessness and postoperative hallucinatory episodes (sometimes associated with transient periods of mental depression); extrapyramidal symptoms (dystonia, akathisia and oculogyric crisis) have been observed up to 24 hours postoperatively. When they occur, extrapyramidal symptoms can usually be controlled with anti-parkinson agents. Postoperative drowsiness is also frequently reported following the use of neuroleptics with fentanyl citrate. Cases of cardiac dysrhythmias, cardiac arrest, and death have been reported following the use of fentanyl citrate with a neuroleptic agent. 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 has been reported with ingredients contained in Fentanyl Citrate Injection Androgen deficiency : Cases of androgen deficiency have occurred with chronic use of opioids [see Clinical Pharmacology (12.2) ] . Most common serious adverse reactions were respiratory depression, apnea, rigidity, and bradycardia. (6) To report SUSPECTED ADVERSE REACTIONS, contact Hikma Pharmaceuticals USA Inc. at 1-877-845-0689 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

4 CONTRAINDICATIONS Fentanyl Citrate Injection is contraindicated in patients with: Hypersensitivity to fentanyl (e.g., anaphylaxis) [See Adverse Reactions (6) ] Hypersensitivity to fentanyl (4)

11 DESCRIPTION Fentanyl Citrate Injection is an opioid agonist, available as a sterile, non-pyrogenic solution containing fentanyl citrate as the active pharmaceutical ingredient, for intravenous or intramuscular administration. Fentanyl citrate is chemically identified as N -(1-Phenethyl-4-piperidyl)propionanilide citrate (1:1) with the following structural formula: C 22 H 28 N 2 O • C 6 H 8 O 7 Molecular Weight is 528.59 Each mL contains fentanyl citrate equivalent to 50 mcg fentanyl base in Water for Injection. Sodium hydroxide and/or hydrochloric acid added, if needed, for pH adjustment. The pH range is 4.0 – 7.5. Contains no preservative. Structural Formula

2 DOSAGE AND ADMINISTRATION Fentanyl Citrate Injection should be administered only by persons specifically trained in the use of intravenous anesthetics and management of the respiratory effects of potent opioids. Ensure that an opioid antagonist, resuscitative and intubation equipment, and oxygen are readily available ( 2.1 ). Individualize dosing based on the factors such as age, body weight, physical status, underlying pathological condition, use of other drugs, type of anesthesia to be used, and the surgical procedure involved. ( 2.1 ) Initiate treatment in adults with 50 mcg to 100 mcg. ( 2.2 ) Initiate treatment in children 2 to 12 years of age, with a reduced dose as low as 2 mcg/kg to 3 mcg/kg. ( 2.2 ) 2.1 Important Dosage and Administration Instructions Fentanyl Citrate Injection should be administered only by persons specifically trained in the use of intravenous anesthetics and management of the respiratory effects of potent opioids. Ensure that an opioid antagonist, resuscitative and intubation equipment, and oxygen are readily available. Individualize dosage based on factors such as age, body weight, physical status, underlying pathological condition, use of other drugs, type of anesthesia to be used, and the surgical procedure involved. Monitor vital signs routinely. As with other potent opioids, the respiratory depressant effect of fentanyl may persist longer than the measured analgesic effect. The total dose of all opioid agonists administered should be considered by the practitioner before ordering opioid analgesics during recovery from anesthesia. If Fentanyl Citrate Injection is administered with a CNS depressant, become familiar with the properties of each drug, particularly each product’s duration of action. In addition, when such a combination is used, fluids and other countermeasures to manage hypotension should be available [see Warnings and Precautions (5.4) ] . Inspect parenteral drug products visually for particulate matter and discoloration prior to administration, whenever solution and container permit. 2.2 Dosage Premedication in Adults 50 to 100 mcg may be administered intramuscularly 30 to 60 minutes prior to surgery. Adjunct to General Anesthesia See Dosage Range Charts below. Table 1: Dosage Range Chart Total Dosage (expressed as fentanyl base) Low Dose —2 mcg/kg For use in minor, but painful, surgical procedures. May also provide some pain relief in the immediate postoperative period. Moderate Dose —2 mcg/kg to 20 mcg/kg For use in more major surgical procedures, in addition to adequate analgesia, may abolish some of the stress response. Expect respiratory depression requiring artificial ventilation during anesthesia and careful observation of ventilation postoperatively is essential. High dose —20 mcg/kg to 50 mcg/kg For open heart surgery and certain more complicated neurosurgical and orthopedic procedures where surgery is more prolonged, and the stress response to surgery would be detrimental to the well-being of the patient. In conjunction with nitrous oxide/oxygen has been shown to attenuate the stress response as defined by increased levels of circulating growth hormone, catecholamine, ADH and prolactin. Expect the need of postoperative ventilation and observation due to extended post-operative respiratory depression. Maintenance Dose (expressed as fentanyl base) Low Dose —2 mcg/kg Additional dosages infrequently needed in these minor procedures. Moderate Dose —2 mcg/kg to 20 mcg/kg 25 mcg to 100 mcg Administer intravenously or intramuscularly as needed when movement and/or changes in vital signs indicate surgical stress or lightening of analgesia. High Dose —20 mcg/kg to 50 mcg/kg Maintenance dosage [ranging from 25 mcg to one half the initial loading dose] as needed based on vital signs indicative of stress and lightening of analgesia. Individualize the dosage especially if the anticipated remaining operative time is short. Adjunct to Regional Anesthesia 50 mcg to 100 mcg may be administered intramuscularly or slowly intravenously, over one to two minutes, when additional analgesia is required. Postoperatively (recovery room) 50 mcg to 100 mcg may be administered intramuscularly for the control of pain, tachypnea and emergence delirium. The dose may be repeated in one to two hours as needed. For Induction and Maintenance in Children 2 to 12 Years of Age A reduced dose as low as 2 mcg/kg to 3 mcg/kg is recommended. As a General Anesthetic As a technique to attenuate the responses to surgical stress without the use of additional anesthetic agents, doses of 50 mcg/kg to 100 mcg/kg may be administered with oxygen and a muscle relaxant. In certain cases, doses up to 150 mcg/kg may be necessary to produce this anesthetic effect. It has been used for open heart surgery and certain other major surgical procedures in patients for whom protection of the myocardium from excess oxygen demand is particularly indicated, and for certain complicated neurological and orthopedic procedures. 2.3 Instructions for Use of Fentanyl Citrate Injection Prefilled Syringe CAUTION: Glass syringes may malfunction, break or clog when connected to some Needleless Luer Access Devices (NLADs) and needles. The external collar must remain attached to the syringe (See Figure 1) . Spontaneous disconnection of this glass syringe from needles and NLADs with leakage of drug product may occur. Assure that the needle or NLAD is securely attached before beginning the injection. Inspect the glass syringe-needle or glass syringe-NLAD connection before and during administration. Figure 1 Inspect the integrity of the plastic tube, cap and tamper evident seal. Do not use if the tamper evident seal has been damaged. Break the tamper evident seal when removing the cap to access the syringe. 3. Push plunger rod slightly to break the stopper loose while tip cap is still on. 4. Remove tip cap by twisting it off. (See Figure 2) Figure 2 5. Connect the syringe to an appropriate injection connection. 6. Depress plunger rod to deliver the required dose. Figure 1 Figure 2

1 INDICATIONS AND USAGE Fentanyl Citrate Injection is indicated for: analgesic action of short duration during the anesthetic periods, premedication, induction and maintenance, and in the immediate postoperative period (recovery room) as the need arises. use as a narcotic analgesic supplement in general or regional anesthesia. administration with a neuroleptic as an anesthetic premedication, for the induction of anesthesia and as an adjunct in the maintenance of general and regional anesthesia. use as an anesthetic agent with oxygen in selected high risk patients, such as those undergoing open heart surgery or certain complicated neurological or orthopedic procedures. Fentanyl Citrate Injection is indicated for: analgesic action of short duration during the anesthetic periods, premedication, induction and maintenance, and in the immediate postoperative period (recovery room) as the need arises. use as an opioid analgesic supplement in general or regional anesthesia. administration with a neuroleptic as an anesthetic premedication, for the induction of anesthesia and as an adjunct in the maintenance of general and regional anesthesia. use as an anesthetic agent with oxygen in selected high risk patients, such as those undergoing open heart surgery or certain complicated neurological or orthopedic procedures.

9 DRUG ABUSE AND DEPENDENCE 9.1 Controlled Substance Fentanyl Citrate Injection contains fentanyl, a Schedule II controlled drug substance. 9.2 Abuse Fentanyl Citrate Injection contains fentanyl, a substance with a high potential for abuse similar to other opioids including hydrocodone, hydromorphone, methadone, morphine, oxycodone, oxymorphone, and tapentadol. Fentanyl Citrate Injection can be abused and is subject to misuse, addiction, and criminal diversion [see Warnings and Precautions (5.1) ] . Prescription drug abuse is the intentional non-therapeutic use of a prescription drug, even once, for its rewarding psychological or physiological effects. Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that develop after repeated substance use and includes: a strong desire to take the drug, difficulties in controlling its use, persisting in its use despite harmful consequences, a higher priority given to drug use than to other activities and obligations, increased tolerance, and sometimes a physical withdrawal. Fentanyl Citrate Injection, like other opioids, can be diverted for non-medical use into illicit channels of distribution. Careful record-keeping of prescribing information, including quantity, frequency, and renewal requests, as required by state and federal law, is strongly advised. Risks Specific to Abuse of Fentanyl Citrate Injection Abuse of Fentanyl Citrate Injection poses a risk of overdose and death. The risk is increased with concurrent use of Fentanyl Citrate Injection with alcohol and other central nervous system depressants. Parenteral drug abuse is commonly associated with transmission of infectious diseases such as hepatitis and HIV. 9.3 Dependence Both tolerance and physical dependence can develop during chronic opioid therapy. Tolerance is the need for increasing doses of opioids to maintain a defined effect such as analgesia (in the absence of disease progression or other external factors). Tolerance may occur to both the desired and undesired effects of drugs, and may develop at different rates for different effects. Physical dependence results in withdrawal symptoms after abrupt discontinuation or a significant dosage reduction of a drug. Withdrawal also may be precipitated through the administration of drugs with opioid antagonist activity (e.g., naloxone, nalmefene), mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine), or partial agonists (e.g., buprenorphine). Physical dependence may not occur to a clinically significant degree until after several days to weeks of continued opioid usage.

10 OVERDOSAGE Clinical Presentation Acute overdose with Fentanyl Citrate Injection can be manifested by respiratory depression, somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, constricted pupils, and, in some cases, pulmonary edema, bradycardia, hypotension, partial or complete airway obstruction, atypical snoring, and death. Marked mydriasis rather than miosis may be seen with hypoxia in overdose situations [see Clinical Pharmacology (12.2) ] . Treatment of Overdose In case of overdose, priorities are the reestablishment of a patent and protected airway and institution of assisted or controlled ventilation, if needed. Employ other supportive measures (including oxygen and vasopressors) in the management of circulatory shock and pulmonary edema as indicated. Cardiac arrest or arrhythmias will require advanced life-support techniques. The opioid antagonists, naloxone or nalmefene, are specific antidotes to respiratory depression resulting from opioid overdose. For clinically significant respiratory or circulatory depression secondary to fentanyl overdose, administer an opioid antagonist. Opioid antagonists should not be administered in the absence of clinically significant respiratory or circulatory depression secondary to opioid overdose. Because the duration of opioid reversal is expected to be less than the duration of action of fentanyl in Fentanyl Citrate Injection, carefully monitor the patient until spontaneous respiration is reliably re-established. If the response to an opioid antagonist is suboptimal or only brief in nature, administer additional antagonist as directed by the product’s prescribing information. In an individual physically dependent on opioids, administration of the recommended usual dosage of the antagonist will precipitate an acute withdrawal syndrome. The severity of the withdrawal symptoms experienced will depend on the degree of physical dependence and the dose of the antagonist administered. If a decision is made to treat serious respiratory depression in the physically dependent patient, administration of the antagonist should be initiated with care and by titration with smaller than usual doses of the antagonist.

7 DRUG INTERACTIONS Table 2 includes clinically significant drug interactions with Fentanyl Citrate Injection. Table 2: Clinically Significant Drug Interactions with Fentanyl Citrate Injection Inhibitors of CYP3A4 Clinical Impact : The concomitant use of Fentanyl Citrate Injection 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 Citrate Injection is achieved [see Warnings and Precautions (5.3) ] . After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the fentanyl 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 Citrate Injection until stable drug effects are achieved [see Dosage and Administration (2.1) ] . Monitor patients for respiratory depression and sedation at frequent intervals. If a CYP3A4 inhibitor is discontinued, consider increasing the Fentanyl Citrate Injection 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), grapefruit juice CYP3A4 Inducers Clinical Impact: The concomitant use of Fentanyl Citrate Injection 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 (5.3) ] . 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 Citrate Injection dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. If a CYP3A4 inducer is discontinued, consider Fentanyl Citrate Injection dosage reduction and monitor for signs of respiratory depression. Examples: Rifampin, carbamazepine, phenytoin Benzodiazepines and Other Central Nervous System (CNS) Depressants Clinical Impact: The concomitant use of Fentanyl Citrate Injection with CNS depressants may result in decreased pulmonary artery pressure and may cause hypotension. Even small dosages of diazepam may cause cardiovascular depression when added to high dose or anesthetic dosages of Fentanyl Citrate Injection. As postoperative analgesia, concomitant use of Fentanyl Citrate Injection can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death. Intervention: As postoperative analgesia, start with a lower dose of Fentanyl Citrate Injection and monitor patients for signs of respiratory depression, sedation, and hypotension. Fluids or other measures to counter hypotension should be available [see Warnings and Precautions (5.4) ] . Examples: Benzodiazepines and other sedatives/hypnotics, anxiolytics, barbiturates, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, 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 (5.7) ] . Intervention: If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue Fentanyl Citrate Injection 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 effect 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 Clinical Impact: MAOI interactions with opioids may manifest as serotonin syndrome [see Warnings and Precautions (5.7) ] or opioid toxicity (e.g., respiratory depression, coma) [see Warnings and Precautions (5.2) ] Intervention: The use of Fentanyl Citrate Injection 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 Citrate Injection and/or precipitate withdrawal symptoms. Intervention : Avoid concomitant use. Examples: Butorphanol, nalbuphine, pentazocine, buprenorphine. Muscle Relaxants Clinical Impact: Fentanyl may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Intervention: Monitor patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of Fentanyl Citrate Injection and/or the muscle relaxant as necessary. Diuretics Clinical Impact: Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Intervention: Monitor 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 : Monitor patients for signs of urinary retention or reduced gastric motility when Fentanyl Citrate Injection is used concomitantly with anticholinergic drugs . Neuroleptics Clinical Impact: Elevated blood pressure, with and without pre-existing hypertension, has been reported following administration of Fentanyl Citrate Injection combined with a neuroleptic [see Warnings and Precautions (5.13) ] . Intervention: ECG monitoring is indicated when a neuroleptic agent is used in conjunction with Fentanyl Citrate Injection as an anesthetic premedication, for the induction of anesthesia, or as an adjunct in the maintenance of general or regional anesthesia. Nitrous oxide Clinical Impact: Nitrous oxide has been reported to produce cardiovascular depression when given with higher doses of Fentanyl Citrate Injection. Intervention: Monitor patients for signs of cardiovascular depression that may be greater than otherwise expected. Concomitant Use of CNS Depressants : May decrease pulmonary arterial pressure and may cause hypotension. See FPI for management instructions. For post-operative pain, start with the lowest effective dosage and monitor for potentiation of CNS depressant effects. (5.4, 7) Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics : Avoid use with Fentanyl Citrate Injection because they may reduce the analgesic effect of Fentanyl Citrate Injection or precipitate withdrawal symptoms. (7)

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Fentanyl Citrate Injection is an opioid agonist, whose principal actions of therapeutic value are analgesia and sedation. 12.2 Pharmacodynamics Effects on the Central Nervous System Fentanyl produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and electrical stimulation. Fentanyl causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomic (e.g., pontine lesions of hemorrhagic or ischemic origins may produce similar findings). Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations. Effects on the Gastrointestinal Tract and Other Smooth Muscle Fentanyl causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach and duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm, resulting in constipation. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions, spasm of sphincter of Oddi, and transient elevations in serum amylase. Effects on the Cardiovascular System Fentanyl produces peripheral vasodilation which may result in orthostatic hypotension or syncope. Manifestations of histamine release and/or peripheral vasodilation may include pruritis, flushing, red eyes, sweating, and/or orthostatic hypotension. Effects on the Endocrine System Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and lutenizing hormone (LH) in humans. They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon. Chronic use of opioids may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date [see Adverse Reactions (6) ] . Effects on the Immune System Opioids have been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive. Concentration – Efficacy Relationships A dose of 100 mcg of Fentanyl Citrate Injection is approximately equivalent in analgesic activity to 10 mg of morphine or 75 mg of meperidine. The minimum effective analgesic concentration will vary widely among patients, especially among patients who have been previously treated with potent agonist opioids. The minimum effective analgesic concentration of fentanyl for any individual patient may increase over time due to an increase in pain, the development of a new pain syndrome and/or the development of analgesic tolerance [see Dosage and Administration (2.1) ] . The onset of action of fentanyl is almost immediate when the drug is given intravenously; however, the maximal analgesic effect may not be noted for several minutes. The usual duration of action of the analgesic effect is 30 to 60 minutes after a single intravenous dose of up to 100 mcg. Following intramuscular administration, the onset of action is from seven to eight minutes, and the duration of action is one to two hours. Concentration – Adverse Reaction Relationships There is a relationship between increasing fentanyl plasma concentration and increasing frequency of dose-related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid-tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions [see Dosage and Administration (2.1) ] . The onset of action of fentanyl is almost immediate when the drug is given intravenously; however, the maximal respiratory depressant effect may not be noted for several minutes. As with longer acting narcotic analgesics, the duration of the respiratory depressant effect of fentanyl may be longer than the analgesic effect. The following observations have been reported concerning altered respiratory response to CO 2 stimulation following administration of fentanyl citrate: Diminished sensitivity to CO 2 stimulation may persist longer than depression of respiratory rate. (Altered sensitivity to CO 2 stimulation has been demonstrated for up to four hours following a single dose of 600 mcg fentanyl to healthy volunteers.) Fentanyl frequently slows the respiratory rate, duration and degree of respiratory depression being dose related. The peak respiratory depressant effect of a single intravenous dose of fentanyl citrate is noted 5 to 15 minutes following injection [see Warnings and Precautions (5.2) ] . 12.3 Pharmacokinetics Fentanyl Citrate Injection is administered by the intravenous or intramuscular route. The pharmacokinetics of fentanyl can be described as a three-compartment model. Distribution Fentanyl plasma protein binding capacity increases with increasing ionization of the drug. Alterations in pH may affect its distribution between plasma and the central nervous system. It accumulates in skeletal muscle and fat and is released slowly into the blood. The volume of distribution for fentanyl is 4 L/kg. It has a distribution time of 1.7 minutes and redistribution time of 13 minutes. Elimination The terminal elimination half-life is 219 minutes. Fentanyl, which is primarily transformed in the liver, demonstrates a high first pass clearance and releases approximately 75% of an intravenous dose in urine, mostly as metabolites with less than 10% representing the unchanged drug. Approximately 9% of the dose is recovered in the feces, primarily as metabolites.

12.1 Mechanism of Action Fentanyl Citrate Injection is an opioid agonist, whose principal actions of therapeutic value are analgesia and sedation.

12.2 Pharmacodynamics Effects on the Central Nervous System Fentanyl produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and electrical stimulation. Fentanyl causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomic (e.g., pontine lesions of hemorrhagic or ischemic origins may produce similar findings). Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations. Effects on the Gastrointestinal Tract and Other Smooth Muscle Fentanyl causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach and duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm, resulting in constipation. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions, spasm of sphincter of Oddi, and transient elevations in serum amylase. Effects on the Cardiovascular System Fentanyl produces peripheral vasodilation which may result in orthostatic hypotension or syncope. Manifestations of histamine release and/or peripheral vasodilation may include pruritis, flushing, red eyes, sweating, and/or orthostatic hypotension. Effects on the Endocrine System Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and lutenizing hormone (LH) in humans. They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon. Chronic use of opioids may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date [see Adverse Reactions (6) ] . Effects on the Immune System Opioids have been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive. Concentration – Efficacy Relationships A dose of 100 mcg of Fentanyl Citrate Injection is approximately equivalent in analgesic activity to 10 mg of morphine or 75 mg of meperidine. The minimum effective analgesic concentration will vary widely among patients, especially among patients who have been previously treated with potent agonist opioids. The minimum effective analgesic concentration of fentanyl for any individual patient may increase over time due to an increase in pain, the development of a new pain syndrome and/or the development of analgesic tolerance [see Dosage and Administration (2.1) ] . The onset of action of fentanyl is almost immediate when the drug is given intravenously; however, the maximal analgesic effect may not be noted for several minutes. The usual duration of action of the analgesic effect is 30 to 60 minutes after a single intravenous dose of up to 100 mcg. Following intramuscular administration, the onset of action is from seven to eight minutes, and the duration of action is one to two hours. Concentration – Adverse Reaction Relationships There is a relationship between increasing fentanyl plasma concentration and increasing frequency of dose-related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid-tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions [see Dosage and Administration (2.1) ] . The onset of action of fentanyl is almost immediate when the drug is given intravenously; however, the maximal respiratory depressant effect may not be noted for several minutes. As with longer acting narcotic analgesics, the duration of the respiratory depressant effect of fentanyl may be longer than the analgesic effect. The following observations have been reported concerning altered respiratory response to CO 2 stimulation following administration of fentanyl citrate: Diminished sensitivity to CO 2 stimulation may persist longer than depression of respiratory rate. (Altered sensitivity to CO 2 stimulation has been demonstrated for up to four hours following a single dose of 600 mcg fentanyl to healthy volunteers.) Fentanyl frequently slows the respiratory rate, duration and degree of respiratory depression being dose related. The peak respiratory depressant effect of a single intravenous dose of fentanyl citrate is noted 5 to 15 minutes following injection [see Warnings and Precautions (5.2) ] .

12.3 Pharmacokinetics Fentanyl Citrate Injection is administered by the intravenous or intramuscular route. The pharmacokinetics of fentanyl can be described as a three-compartment model. Distribution Fentanyl plasma protein binding capacity increases with increasing ionization of the drug. Alterations in pH may affect its distribution between plasma and the central nervous system. It accumulates in skeletal muscle and fat and is released slowly into the blood. The volume of distribution for fentanyl is 4 L/kg. It has a distribution time of 1.7 minutes and redistribution time of 13 minutes. Elimination The terminal elimination half-life is 219 minutes. Fentanyl, which is primarily transformed in the liver, demonstrates a high first pass clearance and releases approximately 75% of an intravenous dose in urine, mostly as metabolites with less than 10% representing the unchanged drug. Approximately 9% of the dose is recovered in the feces, primarily as metabolites.

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3 DOSAGE FORMS AND STRENGTHS Single-Dose Ampuls, Vials and Prefilled Syringes: Fentanyl Citrate Injection, USP, equivalent to 50 mcg fentanyl base per mL, is a preservative-free solution, available in 2 mL, 5 mL, 20 mL single-dose glass ampuls and 1 mL, 2 mL, 5 mL, 20 mL, 50 mL single-dose glass vials and 0.5 mL and 1 mL single-dose, prefilled, glass syringes. Fentanyl Citrate Injection, equivalent to 50 mcg f entanyl base per mL, is a preservative-free solution, available in 2 mL, 5 mL, 20 mL single-dose glass ampuls and 1 mL, 2 mL, 5 mL, 20 mL, 50 mL single-dose glass vials and 0.5 mL and 1 mL single-dose prefilled, glass syringes ( 3 )

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13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Long-term studies in animals to evaluate the carcinogenic potential of fentanyl citrate have not been conducted. Mutagenesis No formal studies to assess the mutagenic potential of fentanyl citrate have been conducted. Impairment of Fertility Decreased pregnancy rates occurred in a multigenerational study in which pregnant rats were treated subcutaneously during the first 21 days of pregnancy with 160 mcg/kg to 1250 mcg/kg fentanyl (0.26 times to 2.0 times a human dose of 100 mcg/kg based on body surface area). Studies in animals to characterize the effect of fentanyl on male fertility have not been conducted.

13 NONCLINICAL TOXICOLOGY 13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Long-term studies in animals to evaluate the carcinogenic potential of fentanyl citrate have not been conducted. Mutagenesis No formal studies to assess the mutagenic potential of fentanyl citrate have been conducted. Impairment of Fertility Decreased pregnancy rates occurred in a multigenerational study in which pregnant rats were treated subcutaneously during the first 21 days of pregnancy with 160 mcg/kg to 1250 mcg/kg fentanyl (0.26 times to 2.0 times a human dose of 100 mcg/kg based on body surface area). Studies in animals to characterize the effect of fentanyl on male fertility have not been conducted.

NDA019101

Fentanyl Citrate

Fentanyl Citrate

0641-6247

HUMAN PRESCRIPTION DRUG

INTRAMUSCULAR,INTRAVENOUS

PRINCIPAL DISPLAY PANEL NDC 0641- 6247 -01 Rx only Fentanyl Citrate Inj., USP CII 50 mcg/mL For Intravenous or Intramuscular use Protect from light Discard unused portion 1 mL Single Dose Vial NDC 0641- 6247 -25 Rx only Fentanyl Citrate Inj., USP CII 50 mcg/mL For Intravenous or Intramuscular use Preservative Free 25 x 1 mL Single Dose Vials NDC 0641-6247-01 Rx only Fentanyl Citrate Inj., USP CII 50 mcg/mL For Intravenous or Intramuscular use Protect from light Discard unused portion 1 mL Single Dose Vial NDC 0641-6247-25 Rx only Fentanyl Citrate Inj., USP CII 50 mcg/mL For Intravenous or Intramuscular use Preservative Free 25 x 1 mL Single Dose Vials

RECENT MAJOR CHANGES Dosage and Administration ( 2.3 ) 01/2023

Manufactured by: Hikma Pharmaceuticals USA Inc. Berkeley Heights, NJ 07922 Revised: March 2023 462-254-11

17 PATIENT COUNSELING INFORMATION Serotonin Syndrome Inform patients that Fentanyl Citrate Injection could cause a rare but potentially life-threatening condition resulting from concomitant administration of serotonergic drugs. Instruct patients to inform their healthcare provider if they are taking, or plan to take serotonergic medications [see Warnings and Precautions (5.7) , Drug Interactions (7) ] . Constipation Advise patients of the potential for severe constipation, [see Clinical Pharmacology (12.2) ] .

8.5 Geriatric Use Elderly patients (aged 65 years or older) may have increased sensitivity to fentanyl. In general, use caution when selecting a dosage for an elderly patient, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy. Respiratory depression is the chief risk for elderly patients treated with opioids, and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration. Titrate the dosage of Fentanyl Citrate Injection slowly in geriatric patients and monitor closely for signs of central nervous system and respiratory depression [see Warnings and Precautions (5.2) ] . Fentanyl is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

8.2 Lactation Risk Summary Fentanyl is present in breast milk. One published lactation study reports a relative infant dose of fentanyl of 0.38%. However, there is insufficient information to determine the effects of fentanyl on the breastfed infant and the effects of fentanyl on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Fentanyl Citrate Injection and any potential adverse effects on the breastfed infant from Fentanyl Citrate Injection or from the underlying maternal condition. Clinical Considerations Monitor infants exposed to fentanyl 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 Chronic use of opioids 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), Clinical Pharmacology (12.2), Nonclinical Toxicology (13.1) ] .

8.4 Pediatric Use The safety and efficacy of Fentanyl Citrate Injection in pediatric patients under two years of age has not been established. Rare cases of unexplained clinically significant methemoglobinemia have been reported in premature neonates undergoing emergency anesthesia and surgery which included combined use of fentanyl, pancuronium and atropine. A direct cause and effect relationship between the combined use of these drugs and the reported cases of methemoglobinemia has not been established.

8.1 Pregnancy Risk Summary Prolonged use of opioid analgesics during pregnancy may cause neonatal opioid withdrawal syndrome. Available data with Fentanyl Citrate Injection 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. No evidence of malformations was 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 2-4% and 15-20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Prolonged use of opioid analgesics 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. Labor or Delivery There are insufficient data to support the use of fentanyl in labor or delivery. Therefore, such use is not recommended. Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. Fentanyl Citrate Injection is not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. Opioid analgesics, including Fentanyl Citrate Injection, can prolong labor through actions which 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 dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Data Animal Data Fentanyl has been shown to be embryocidal in pregnant rats at doses of 30 mcg/kg intravenously (0.05 times the human dose of 100 mcg/kg on a mg/m 2 basis) and 160 mcg/kg subcutaneously (0.26 times the human dose of 100 mcg/kg on a mg/m 2 basis). There was no evidence of teratogenicity reported. 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 0.81 times the human dose of 100 mcg/kg on a mg/m 2 basis.

8 USE IN SPECIFIC POPULATIONS Pregnancy : May cause fetal harm. (8.1) Lactation : Infants exposed to Fentanyl Citrate Injection through breast milk should be monitored for excess sedation and respiratory depression. (8.2) Geriatric Patients : Titrate slowly and monitor for CNS and respiratory depression. (8.5) 8.1 Pregnancy Risk Summary Prolonged use of opioid analgesics during pregnancy may cause neonatal opioid withdrawal syndrome. Available data with Fentanyl Citrate Injection 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. No evidence of malformations was 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 2-4% and 15-20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Prolonged use of opioid analgesics 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. Labor or Delivery There are insufficient data to support the use of fentanyl in labor or delivery. Therefore, such use is not recommended. Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. Fentanyl Citrate Injection is not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. Opioid analgesics, including Fentanyl Citrate Injection, can prolong labor through actions which 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 dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Data Animal Data Fentanyl has been shown to be embryocidal in pregnant rats at doses of 30 mcg/kg intravenously (0.05 times the human dose of 100 mcg/kg on a mg/m 2 basis) and 160 mcg/kg subcutaneously (0.26 times the human dose of 100 mcg/kg on a mg/m 2 basis). There was no evidence of teratogenicity reported. 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 0.81 times the human dose of 100 mcg/kg on a mg/m 2 basis. 8.2 Lactation Risk Summary Fentanyl is present in breast milk. One published lactation study reports a relative infant dose of fentanyl of 0.38%. However, there is insufficient information to determine the effects of fentanyl on the breastfed infant and the effects of fentanyl on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Fentanyl Citrate Injection and any potential adverse effects on the breastfed infant from Fentanyl Citrate Injection or from the underlying maternal condition. Clinical Considerations Monitor infants exposed to fentanyl 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 Chronic use of opioids 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), Clinical Pharmacology (12.2), Nonclinical Toxicology (13.1) ] . 8.4 Pediatric Use The safety and efficacy of Fentanyl Citrate Injection in pediatric patients under two years of age has not been established. Rare cases of unexplained clinically significant methemoglobinemia have been reported in premature neonates undergoing emergency anesthesia and surgery which included combined use of fentanyl, pancuronium and atropine. A direct cause and effect relationship between the combined use of these drugs and the reported cases of methemoglobinemia has not been established. 8.5 Geriatric Use Elderly patients (aged 65 years or older) may have increased sensitivity to fentanyl. In general, use caution when selecting a dosage for an elderly patient, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy. Respiratory depression is the chief risk for elderly patients treated with opioids, and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration. Titrate the dosage of Fentanyl Citrate Injection slowly in geriatric patients and monitor closely for signs of central nervous system and respiratory depression [see Warnings and Precautions (5.2) ] . Fentanyl is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. 8.6 Hepatic Impairment Fentanyl Citrate Injection should be administered with caution to patients with liver dysfunction because of the extensive hepatic metabolism. Reduce the dosage as needed and monitor closely for signs of respiratory depression, sedation, and hypotension. 8.7 Renal Impairment Fentanyl Citrate Injection should be administered with caution to patients with kidney dysfunction because of the renal excretion of Fentanyl Citrate Injection and its metabolites. Reduce the dosage as needed and monitor closely for signs of respiratory depression, sedation, and hypotension.

16 HOW SUPPLIED/STORAGE AND HANDLING Fentanyl Citrate Injection, equivalent to 50 mcg fentanyl base per mL, is a preservative-free solution, supplied as follows: NDC 0641-6024-10 2 mL Single Dose ampuls packaged in 10s NDC 0641-6247-25 1 mL Single Dose vials packaged in 25s NDC 0641-6027-25 2 mL Single Dose vials packaged in 25s NDC 0641-6025-10 5 mL Single Dose ampuls packaged in 10s NDC 0641-6028-10 5 mL Single Dose vials packaged in 10s NDC 0641-6248-10 1 mL Single Dose prefilled syringes in 10s NDC 0641-6249-10 0.5 mL Single Dose prefilled syringes in 10s For Intravenous Use by Hospital Personnel Specifically Trained in the Use of Narcotic Analgesics: NDC 0641-6026-05 20 mL Single Dose ampuls packaged in 5s NDC 0641-6029-01 20 mL Single Dose vials packaged individually NDC 0641-6030-01 50 mL Single Dose vials packaged individually PROTECT FROM LIGHT. Keep covered in carton until time of use. Store at 20˚C to 25˚C (68˚F to 77˚F), excursions permitted to 15˚C to 30˚C (59˚F to 86˚F) [See USP Controlled Room Temperature]. Contains no preservative. DISCARD ANY UNUSED CONTENTS. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. To report SUSPECTED ADVERSE REACTIONS, contact Hikma Pharmaceuticals USA Inc. at 1-877-845-0689, or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. For Product Inquiry call 1-877-845-0689.

WARNING: RISK OF ADDICTION, ABUSE, AND MISUSE; LIFE-THREATENING RESPIRATORY DEPRESSION; CYTOCHROME P450 3A4 INTERACTION; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS Addiction, Abuse, and Misuse Fentanyl Citrate Injection exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death. Assess each patient’s risk prior to prescribing Fentanyl Citrate Injection, and monitor all patients regularly for the development of these behaviors and conditions [see Warnings and Precautions (5.1) ] . Life-Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression may occur with use of Fentanyl Citrate Injection. Monitor for respiratory depression, especially during initiation of Fentanyl Citrate Injection or following a dose increase [see Warnings and Precautions (5.2) ] . Cytochrome P450 3A4 Interaction The concomitant use of Fentanyl Citrate Injection with all cytochrome P450 3A4 inhibitors may result in an increase in fentanyl plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression. In addition, discontinuation of a concomitantly used cytochrome P450 3A4 inducer may result in an increase in fentanyl plasma concentration. Monitor patients receiving Fentanyl Citrate Injection and any CYP3A4 inhibitor or inducer [see Warnings and Precautions (5.3) , Drug Interactions (7) , Clinical Pharmacology (12.3) ] Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death [see Warnings and Precautions (5.4) , Drug Interactions (7) ]. Reserve concomitant prescribing of Fentanyl Citrate Injection and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Follow patients for signs and symptoms of respiratory depression and sedation. WARNING: RISK OF ADDICTION, ABUSE, AND MISUSE; LIFE­ THREATENING RESPIRATORY DEPRESSION; CYTOCHROME P450 3A4 INTERACTION; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS See full prescribing information for complete boxed warning. Fentanyl Citrate Injection exposes users to risks of addiction, abuse, and misuse, which can lead to overdose and death. Assess patient’s risk before prescribing and monitor regularly for these behaviors and conditions ( 5.1 ) Serious, life-threatening, or fatal respiratory depression may occur. Monitor closely, especially upon initiation or following a dose increase. ( 5.2 ) Concomitant use with CYP3A4 inhibitors (or discontinuation of CYP3A4 inducers) can result in a fatal overdose of fentanyl. ( 5.3 , 7 , 12.3 ) Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for use in patients for whom alternative treatment options are inadequate; limit dosages and durations to the minimum required; and follow patients for signs and symptoms of respiratory depression and sedation. ( 5.4 , 7 )