Desflurane

SUPRANE, a general anesthetic, is an inhalation agent indicated:

• for induction and/or maintenance of anesthesia in adults ( 1.1 )
• for maintenance of anesthesia in pediatric patients following induction with agents other than SUPRANE and intubation.

1.1 Induction of Anesthesia SUPRANE is indicated as an inhalation agent for induction of anesthesia for inpatient and outpatient surgery in adults. SUPRANE is contraindicated as an inhalation agent for the induction of anesthesia in pediatric patients because of a high incidence of moderate to severe upper airway adverse events.

1.2 Maintenance of Anesthesia SUPRANE is indicated as an inhalation agent for maintenance of anesthesia for inpatient and outpatient surgery in adults and in pediatric patients. After induction of anesthesia with agents other than SUPRANE, and tracheal intubation, SUPRANE is indicated for maintenance of anesthesia in infants and children. SUPRANE is not approved for maintenance of anesthesia in non-intubated children due to an increased incidence of respiratory adverse reactions, including coughing, laryngospasm, and secretions [ See Warnings and Precautions (5.3) and Clinical Studies (14.5) ].

SUPRANE (desflurane, USP) is a colorless, non-flammable, volatile liquid (below 22.8°C) for inhalation, 100% desflurane.

• Liquid (volatile): 100% (3)

The use of SUPRANE is contraindicated in the following conditions:

• Known or suspected genetic susceptibility to malignant hyperthermia [see Warnings and Precautions (5.1) , Clinical Pharmacology (12.5) ] .
• Patients in whom general anesthesia is contraindicated.
• Induction of anesthesia in pediatric patients.
• Patients with known sensitivity to SUPRANE or to other halogenated agents [ See Warnings and Precautions (5.5) ].
• Patients with a history of moderate to severe hepatic dysfunction following anesthesia with SUPRANE or other halogenated agents and not otherwise explained [ See Warnings and Precautions (5.5) ].
• Patients with known or suspected genetic susceptibility to malignant hyperthermia ( 4 )
• Patients in whom general anesthesia is contraindicated ( 4 )
• Induction of anesthesia in pediatric patients ( 4 )
• Patients with known sensitivity to halogenated agents ( 4 )
• Patients with a history of moderate to severe hepatic dysfunction following anesthesia with halogenated agents and not otherwise explained. ( 4 )

• Malignant Hyperthermia : Malignant hyperthermia may occur, especially in individuals with known or suspected susceptibility based on genetic factors or family history. Discontinue triggering agents, administer intravenous dantrolene sodium, and apply supportive therapies. ( 5.1 )
• Perioperative Hyperkalemia : Perioperative hyperkalemia may occur. Patients with latent or overt neuromuscular disease, particularly with Duchenne muscular dystrophy, appear to be most vulnerable. Early, aggressive intervention is recommended. ( 5.2 )
• Respiratory Adverse Reactions in Pediatric Patients : – Not approved for maintenance of anesthesia in non-intubated children due to an increased incidence of respiratory adverse reactions. Monitor and treat accordingly.( 5.3 ) – May cause airway narrowing and increased airway resistance in children with asthma or a history of recent upper airway infection. Monitor and treat accordingly.( 5.3 )
• QT Prolongation : Carefully monitor cardiac rhythm when administering SUPRANE to susceptible patients. ( 5.4 )
• Interactions with Desiccated Carbon Dioxide (CO 2 ) Absorbents : May react with desiccated CO 2 absorbents to produce carbon monoxide. Replace desiccated CO 2 absorbent before administration of SUPRANE. ( 5.5 )
• Hepatobiliary Disorders : May cause sensitivity hepatitis in patients sensitized by previous exposure to halogenated anesthetics. Approach repeated anesthesia with caution. ( 5.6 )
• Pediatric Neurotoxicity : In developing animals, exposures greater than 3 hours cause neurotoxicity. Weigh benefits against potential risks when considering elective procedures in children under 3 years old. ( 5.7 )
• Postoperative Agitation in Children : May cause postoperative agitation during emergence from anesthesia in children. ( 5.9 )

5.1 Malignant Hyperthermia In susceptible individuals, volatile anesthetic agents, including desflurane, may trigger malignant hyperthermia, a skeletal muscle hypermetabolic state leading to high oxygen demand. Fatal outcomes of malignant hyperthermia have been reported. The risk of developing malignant hyperthermia increases with the concomitant administration of succinylcholine and volatile anesthetic agents. SUPRANE can induce malignant hyperthermia in patients with known or suspected susceptibility based on genetic factors or family history, including those with certain inherited ryanodine receptor ( RYR1 ) or dihydropyridine receptor ( CACNA1S ) variants. [see Contraindications (4) , Clinical Pharmacology (12.5) ] Signs consistent with malignant hyperthermia may include hyperthermia, hypoxia, hypercapnia, muscle rigidity (e.g., jaw muscle spasm), tachycardia (e.g., particularly that unresponsive to deepening anesthesia or analgesic medication administration), tachypnea, cyanosis, arrhythmias, hypovolemia, and hemodynamic instability. Skin mottling, coagulopathies, and renal failure may occur later in the course of the hypermetabolic process. Successful treatment of malignant hyperthermia depends on early recognition of the clinical signs. If malignant hyperthermia is suspected, discontinue all triggering agents (i.e., volatile anesthetic agents and succinylcholine), administer intravenous dantrolene sodium, and initiate supportive therapies. Consult prescribing information for intravenous dantrolene sodium for additional information on patient management. Supportive therapies include administration of supplemental oxygen and respiratory support based on clinical need, maintenance of hemodynamic stability and adequate urinary output, management of fluid and electrolyte balance, correction of acid basederangements, and institution of measures to control rising temperature.

5.2 Perioperative Hyperkalemia Use of inhaled anesthetic agents has been associated with rare increases in serum potassium levels that have resulted in cardiac arrhythmias and death in pediatric patients during the postoperative period. Patients with latent as well as overt neuromuscular disease, particularly Duchenne muscular dystrophy, appear to be most vulnerable. Concomitant use of succinylcholine has been associated with most, but not all, of these cases. These patients also experienced significant elevations in serum creatinine kinase levels and, in some cases, changes in urine consistent with myoglobinuria. Despite the similarity in presentation to malignant hyperthermia, none of these patients exhibited signs or symptoms of muscle rigidity or hypermetabolic state. Early and aggressive intervention to treat the hyperkalemia and resistant arrhythmias is recommended, as is subsequent evaluation for latent neuromuscular disease.

5.3 Respiratory Adverse Reactions in Pediatric Patients SUPRANE is not approved for maintenance of anesthesia in non-intubated children due to an increased incidence of respiratory adverse reactions, including coughing, laryngospasm and secretions [ See Clinical Studies (14.5) ]. Children, particularly if 6 years old or younger, who are under an anesthetic maintenance of SUPRANE delivered via laryngeal mask airway (LMA™ mask) are at increased risk for adverse respiratory reactions, e.g., coughing and laryngospasm, especially with removal of the laryngeal mask airway under deep anesthesia [ See Clinical Studies (14.5) ]. Therefore, closely monitor these patients for signs and symptoms associated with laryngospasm and treat accordingly. When SUPRANE is used for maintenance of anesthesia in children with asthma or a history of recent upper airway infection, there is an increased risk for airway narrowing and increases in airway resistance. Therefore, closely monitor these patients for signs and symptoms associated with airway narrowing and treat accordingly . 5.4 QT Prolongation QT prolongation, associated with torsade de pointes, has been reported [see Adverse Reactions (6.2) ]. Carefully monitor cardiac rhythm when administering SUPRANE to susceptible patients (e.g., patients with congenital Long QT Syndrome or patients taking drugs that can prolong the QT interval).

5.5 Interactions with Desiccated Carbon Dioxide Absorbents Desflurane like some other inhalation anesthetics, can react with desiccated carbon dioxide (CO 2 ) absorbents to produce carbon monoxide that may result in elevated levels of carboxyhemoglobin in some patients. Case reports suggest that barium hydroxide lime and soda lime become desiccated when fresh gases are passed through the CO 2 canister at high flow rates over many hours or days. When a clinician suspects that CO 2 absorbent may be desiccated, it should be replaced before the administration of SUPRANE.

5.6 Hepatobiliary Disorders With the use of halogenated anesthetics, disruption of hepatic function, icterus and fatal liver necrosis have been reported; such reactions appear to indicate hypersensitivity. As with other halogenated anesthetic agents, SUPRANE may cause sensitivity hepatitis in patients who have been sensitized by previous exposure to halogenated anesthetics [ See Contraindications (4) ]. Cirrhosis, viral hepatitis or other pre-existing hepatic disease may be a reason to select an anesthetic other than a halogenated anesthetic. As with all halogenated anesthetics, repeated anesthesia within a short period of time should be approached with caution.

5.7 Pediatric Neurotoxicity Published animal studies demonstrate that the administration of anesthetic and sedation drugs that block NMDA receptors and/or potentiate GABA activity increase neuronal apoptosis in the developing brain and result in long-term cognitive deficits when used for longer than 3 hours. The clinical significance of these findings is not clear. However, based on the available data, the window of vulnerability to these changes is believed to correlate with exposures in the third trimester of gestation through the first several months of life, but may extend out to approximately three years of age in humans. [ See Use in Specific Populations (8.1 , 8.4 ), Nonclinical Toxicology (13.2) ]. […]

Most common adverse reactions (incidence> 10%) are coughing, breath holding, apnea, nausea, vomiting. (6) To report SUSPECTED ADVERSE REACTIONS, contact Baxter Healthcare Corporation at 1-800-262-3784 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adverse event information is derived from controlled clinical trials, the majority of which were conducted in the United States. The studies were conducted using a variety of premedications, other anesthetics, and surgical procedures of varying length. Most adverse events reported were mild and transient, and may reflect the surgical procedures, patient characteristics (including disease) and/or medications administered. Of the 2,143 patients exposed to SUPRANE in clinical trials, 370 adults and 152 children were induced with desflurane alone and 987 patients were maintained principally with desflurane. The frequencies given reflect the percent of patients with the event. Each patient was counted once for each type of adverse event. They are presented in alphabetical order according to body system. Table 2 Frequency of Events Occurring in Greater Than 1% of Clinical Trial Patients (in Reports Deemed “Probably Causally Related”) Induction (use as a mask inhalation agent) Adult Patients (N=370): Coughing 34%, breathholding 30%, apnea 15%, increased secretions Incidence of events 3% – 10% , laryngospasm , oxyhemoglobin desaturation (SpO 2 < 90%) , pharyngitis . Maintenance or Recovery Adult and Intubated Pediatric Patients (N=687): Body as a Whole Headache Cardiovascular Bradycardia, hypertension, nodal arrhythmia, tachycardia Digestive Nausea 27%, vomiting 16% Nervous system Increased salivation Respiratory Apnea , breathholding, cough increased , laryngospasm , pharyngitis Special Senses Conjunctivitis (conjunctival hyperemia) Frequency of Events Occurring in Less Than 1% of Patients (in Reports Deemed “Probably Causally Related”) Reported in 3 or more patients, regardless of severity Adverse reactions reported only from postmarketing experience or in the literature, not seen in clinical trials, are considered rare and are italicized. Cardiovascular Arrhythmia, bigeminy, abnormal electrocardiogram, myocardial ischemia, vasodilation Digestive Hepatitis Nervous System Agitation, dizziness Respiratory Asthma, dyspnea, hypoxia Frequency of Events Occurring in Less Than 1% of Clinical Trial Patients (in Reports Deemed “Causal Relationship Unknown”) Reported in 3 or more patients, regardless of severity Body as a Whole Fever Cardiovascular Hemorrhage, myocardial infarction Metabolic and Nutrition Increased creatinine phosphokinase Musculoskeletal System Myalgia Skin and Appendages Pruritus

6.2 Post-Marketing Experience The following adverse reactions have been identified during post-approval use of SUPRANE. Because these reactions are reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Blood and Lymphatic System Disorders : Coagulopathy Metabolism and Nutrition Disorders : Hyperkalemia, Hypokalemia, metabolic acidosis Psychiatric Disorders: Delirium Nervous System Disorders : Convulsion, Post-operative agitation in children Eye Disorders: Ocular icterus Cardiac Disorders: Cardiac arrest, electrocardiogram QT prolonged, torsade de pointes, ventricular failure, ventricular hypokinesia, atrial fibrillation Vascular Disorders: Malignant hypertension, hemorrhage, hypotension, shock Respiratory, Thoracic and Mediastinal Disorders: Respiratory arrest, respiratory failure, respiratory distress, bronchospasm, hemoptysis Gastrointestinal Disorders : Pancreatitis acute, abdominal pain Hepatobiliary Disorders: Hepatic failure, hepatic necrosis, hepatitis, cytolytic hepatitis, cholestasis, jaundice, hepatic function abnormal, liver disorder Skin and Subcutaneous Tissue Disorder : Urticaria, erythema Musculoskeletal, Connective Tissue and Bone Disorders: Rhabdomyolysis General Disorders and Administration Site Conditions: Hyperthermia malignant, asthenia, malaise Investigations: Electrocardiogram ST-T change, electrocardiogram T-wave inversion, tranaminases increased, alanine aminotransferase increased, aspartate aminotransferase increased, blood bilirubin increased, coagulation test abnormal, ammonia increased Injury, Poisoning, and Procedural Complications*: Tachyarrhythmia, palpitations, eye burns, blindness transient, encephalopathy, ulcerative keratitis, ocular hyperemia, visual acuity reduced, eye irritation, eye pain, dizziness, migraine, fatigue, accidental exposure, skin burning sensation, drug administration error *Reactions categorized within this System Organ Class (SOC) were accidental exposures to non-patients.

No clinically significant adverse interactions with commonly used preanesthetic drugs, or drugs used during anesthesia (muscle relaxants, intravenous agents, and local anesthetic agents) were reported in clinical trials. The effect of SUPRANE on the disposition of other drugs has not been determined. Similar to isoflurane, SUPRANE does not predispose to premature ventricular arrhythmias in the presence of exogenously infused epinephrine in swine.

• Concomitant use of N 2 O, benzodiazepines and/or opioids reduces the MAC of SUPRANE. Adjust dose accordingly. ( 7.1 , 7.3 )
• SUPRANE decreases the doses of neuromuscular blocking agents required. Adjust dose accordingly. (7.2)

7.1 Benzodiazepines and Opioids (MAC Reduction) Benzodiazepines and opioids decrease the amount of desflurane (MAC) needed to produce anesthesia. This effect is shown in Table 3 for intravenous midazolam (25-50 µg/kg) and intravenous fentanyl (3-6 µg/kg) in patients of two different age groups. Table 3 SUPRANE MAC with Fentanyl or Midazolam Mean ± SD (percent reduction) Dose 18-30 years 31-65 years No fentanyl 6.4 ± 0.0 6.3 ± 0.4 3 µg/kg fentanyl 3.5 ± 1.9 (46%) 3.1 ± 0.6 (51%) 6 µg/kg fentanyl 3.0 ± 1.2 (53%) 2.3 ± 1.0 (64%) No midazolam 6.9 ± 0.1 5.9 ± 0.6 25 µg/kg midazolam – 4.9 ± 0.9 (16%) 50 µg/kg midazolam – 4.9 ± 0.5 (17%)

7.2 Neuromuscular Blocking Agents Anesthetic concentrations of desflurane at equilibrium (administered for 15 or more minutes before testing) reduced the ED 95 of succinylcholine by approximately 30% and that of atracurium and pancuronium by approximately 50% compared to N 2 O/opioid anesthesia ( see Table 4 ). The effect of desflurane on duration of nondepolarizing neuromuscular blockade has not been studied. Table 4 Dosage of Muscle Relaxant Causing 95% Depression in Neuromuscular Blockade Desflurane Concentration Mean ED 95 (µg/kg) Pancuronium Atracurium Succinylcholine Vecuronium 0.65 MAC 60% N 2 O/O 2 26 133 – – 1.25 MAC 60% N 2 O/O 2 18 119 – – 1.25 MAC O 2 22 120 360 19 Dosage reduction of neuromuscular blocking agents during induction of anesthesia may result in delayed onset of conditions suitable for endotracheal intubation or inadequate muscle relaxation, because potentiation of neuromuscular blocking agents requires equilibration of muscle with the delivered partial pressure of SUPRANE. Among nondepolarizing drugs, pancuronium, atracurium, and vecuronium interactions have been studied. In the absence of specific guidelines: 1. For endotracheal intubation, do not reduce the dose of nondepolarizing muscle relaxants or succinylcholine. 2. During maintenance of anesthesia, the dose of nondepolarizing muscle relaxants is likely to be reduced compared to that during N 2 O/opioid anesthesia. Administration of supplemental doses of muscle relaxants should be guided by the response to nerve stimulation.

7.3 Concomitant use with N 2 O Concomitant administration of N 2 O reduces the MAC of SUPRANE [ See Dosage and Administration (2), Table 1 ].

• Geriatric Use : The minimum alveolar concentration (MAC) of SUPRANE decreases with increasing patient age. ( 8.5 )

8.1 Pregnancy Risk Summary There are no adequate and well-controlled studies in pregnant women. In animal reproduction studies, embryo-fetal toxicity (reduced viable fetuses and/or increased post-implantation loss) was noted in pregnant rats and rabbits administered 1 MAC desflurane for 4 hours a day (4 MAC-hours/day) during organogenesis. Published studies in pregnant primates demonstrate that the administration of anesthetic and sedation drugs that block NMDA receptors and/or potentiate GABA activity during the period of peak brain development increases neuronal apoptosis in the developing brain of the offspring when used for longer than 3 hours. There are no data on pregnancy exposures in primates corresponding to periods prior to the third trimester in humans [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 Labor or Delivery The safety of SUPRANE during labor or delivery has not been demonstrated. SUPRANE is a uterine-relaxant. Data Animal Data Pregnant rats were exposed to 8.2% desflurane (1 MAC; 60% oxygen) for 0.5, 1.0, or 4.0 hours (0.5, 1.0, or 4.0 MAC-hours) per day during organogenesis (Gestation Day 6-15). Embryo-fetal toxicity (increased post-implantation loss and reduced viable fetuses) was noted in the 4 hour treatment group in the presence of maternal toxicity (reduced body weight gain). There was no evidence of malformations in any group. Pregnant rabbits were exposed to 8.9% desflurane (1 MAC; 60% oxygen) for 0.5, 1.0, or 3.0 hours per day during organogenesis (Gestation Days 6-18). Fetal toxicity (reduced viable fetuses) was noted in the 3 hour treatment group in the presence of maternal toxicity (reduced body weight). There was no evidence of malformations in any group. Pregnant rats were exposed to 8.2% desflurane (1 MAC; 60% oxygen) for 0.5, 1.0, or 4.0 hours per day from late gestation and through lactation (Gestation Day 15 to Lactation Day 21). Pup body weights were reduced in the 4 hours per day group in the presence of maternal toxicity (increased mortality and reduced body weight gain). This study did not evaluate neurobehavioral function including learning and memory or reproductive behavior in the first generation (F1) pups. In a published study in primates, administration of an anesthetic dose of ketamine for 24 hours on Gestation Day 122 increased neuronal apoptosis in the developing brain of the fetus. In other published studies, administration of either isoflurane or propofol for 5 hours on Gestation Day 120 resulted in increased neuronal and oligodendrocyte apoptosis in the developing brain of the offspring. With respect to brain development, this time period corresponds to the third trimester of gestation in the human. The clinical significance of these findings is not clear; however, studies in juvenile animals suggest neuroapoptosis correlates with long-term cognitive deficits [ See Warnings and Precautions (5.6) , Use in Specific Populations (8.4) , and Nonclinical Toxicology (13.2) ].

8.2 Lactation It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when SUPRANE is administered to a nursing woman.

8.4 Pediatric Use Respiratory Adverse Reactions in Pediatric Patients SUPRANE is indicated for maintenance of anesthesia in infants and children after induction of anesthesia with agents other than SUPRANE, and tracheal intubation. Is not approved for maintenance of anesthesia in non-intubated children due to an increased incidence of respiratory adverse reactions, including coughing (26%), laryngospasm (13%) and secretions (12%) [ See Clinical Studies (14.5) ]. Children, particularly if 6 years old or younger, who are under an anesthetic maintenance of SUPRANE delivered via laryngeal mask airway (LMA™ mask) are at increased risk for adverse respiratory reactions, e.g., coughing and laryngospasm, especially with removal of the laryngeal mask airway under deep anesthesia [ See Clinical Studies (14.5) ]. Therefore, closely monitor these patients for signs and symptoms associated with laryngospasm and treat accordingly. When SUPRANE is used for maintenance of anesthesia in children with asthma or a history of recent upper airway infection, there is an increased risk for airway narrowing and increases in airway resistance. Therefore, closely monitor these patients for signs and symptoms associated with airway narrowing and treat accordingly. Published juvenile animal studies demonstrate that the administration of anesthetic and sedation drugs, such as SUPRANE, that either block NMDA receptors or potentiate the activity of GABA during the period of rapid brain growth or synaptogenesis, results in widespread neuronal and oligodendrocyte cell loss in the developing brain and alterations in synaptic morphology and neurogenesis. Based on comparisons across species, the window of vulnerability to these changes is believed to correlate with exposures in the third trimester of gestation through the first several months of life, but may extend out to approximately 3 years of age in humans. In primates, exposure to 3 hours of ketamine that produced a light surgical plane of anesthesia did not increase neuronal cell loss, however, treatment regimens of 5 hours or longer of isoflurane increased neuronal cell loss. Data from isoflurane-treated rodents and ketamine-treated primates suggest that the neuronal and oligodendrocyte cell losses are associated with prolonged cognitive deficits in learning and memory. The clinical significance of these nonclinical findings is not known, and healthcare providers should balance the benefits of appropriate anesthesia in pregnant women, neonates, and young children who require procedures with the potential risks suggested by the nonclinical data [ See Warnings and Precautions (5.6) , Use in Specific Populations (8.1) , and Nonclinical Toxicology (13.2) ].

8.5 Geriatric Use The minimum alveolar concentration (MAC) of SUPRANE decreases with increasing patient age. The dose should be adjusted accordingly. The average MAC for SUPRANE in a 70 year old patient is two-thirds the MAC for a 20 year old patient [ See Dosage and Administration (2) Table 1 and Clinical Studies (14.3) ].

8.6 Renal Impairment Concentrations of 1-4% SUPRANE in nitrous oxide/oxygen have been used in patients with chronic renal or hepatic impairment and during renal transplantation surgery. Because of minimal metabolism, a need for dose adjustment in patients with renal and hepatic impairment is not to be expected. Nine patients receiving desflurane (N=9) were compared to 9 patients receiving isoflurane, all with chronic renal insufficiency (serum creatinine 1.5-6.9 mg/dL). No differences in hematological or biochemical tests, including renal function evaluation, were seen between the two groups. Similarly, no differences were found in a comparison of patients receiving either desflurane (N=28) or isoflurane (N=30) undergoing renal transplant.

8.7 Hepatic Impairment Eight patients receiving SUPRANE were compared to six patients receiving isoflurane, all with chronic hepatic disease (viral hepatitis, alcoholic hepatitis, or cirrhosis). No differences in hematological or biochemical tests, including hepatic enzymes and hepatic function evaluation, were seen.