Isoflurane 1 mL/mL Liquid, 100 mL
🆔 Identity & classification
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🏷️ RxNorm drug class
This medicine belongs to the General Anesthetic class.
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🧪 Inactive Ingredients / Excipients
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| Price system | Per mL | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | Not in the retail survey — common for institutional, discontinued, or low-volume packs. | |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · quarterly | No Part D plan price is available for this NDC in our data. | |
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🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Forane 1 mL/mL 10019-0360-40 | Baxter | 6 bottles | — | AN | FDA listed | — |
| Isoflurane 1 mL/mL 12164-0012-10 | Halocarbon | 100 ml | — | AN | FDA listed | — |
| Isoflurane 100 mL/100mL 42677-0326-01 | Shandong | 1 bottle | — | AN | FDA listed | — |
| Isoflurane 250 mL/250mL 42677-0327-01 | Shandong | 1 bottle | — | AN | FDA listed | — |
| Terrell 1 mL/mL 66794-0011-10 | Piramal | 100 ml | — | AN | FDA listed | — |
| Isoflurane 1 mL/mLthis 66794-0017-10 | Piramal | 100 ml | — | AN | FDA listed | — |
| Terrell 1 mL/mL 66794-0019-10 | Piramal | 100 ml | — | AN | FDA listed | — |
| Isoflurane 1 mL/mL 66794-0020-10 | Piramal | 100 ml | — | AN | FDA listed | — |
| Isoflurane, (Volatile for Inhalation) 100 mL/100mL 83301-0071-02 | Mullan | 6 bottles | — | AN | FDA listed | — |
| Isoflurane, (Volatile for Inhalation) 250 mL/250mL 83301-0072-02 | Mullan | 6 bottles | — | AN | FDA listed | — |
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This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
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📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 66794-0017-10 You're viewing this | 100 mL in 1 BOTTLE, GLASS (66794-017-10) | 2011-10-07 | Active |
| 66794-0017-25 | 250 mL in 1 BOTTLE, GLASS (66794-017-25) | 2011-10-07 | Active |
You're viewing the smallest of 2 pack sizes for this product.
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| NDC identity (package / product / labeler codes) | ✓ Available |
| Labeler | ✓ Available |
| Product & package description | ✓ Available |
| Marketing category & status | ✓ Available |
| Active ingredient / dosage form / route | ✓ Available |
| FDA label (SPL via DailyMed) | ✓ Available |
| Package photos | ✓ Available |
| Inactive ingredients (structured) | — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is available. |
| NADAC pharmacy acquisition price (CMS) | — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey. |
| Orange Book / therapeutic-equivalence data | ✓ Available |
| HCPCS J-code billing crosswalk | — Not published for this NDC Most self-administered / retail products have no J-code — that is normal. |
| Medicaid utilization (CMS SDUD) | — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold. |
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📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
1 INDICATIONS AND USAGE Isoflurane USP may be used for induction and maintenance of general anesthesia. Adequate data have not been developed to establish its application in obstetrical anesthesia. Isoflurane USP, a general anesthetic, is an inhalation agent indicated for induction and maintenance of general anesthesia. ( 1 )
⏱️ Dosage and Administration ▾
2 DOSAGE AND ADMINISTRATION • Isoflurane USP should be administered only by persons trained in the administration of general anesthesia. Isoflurane USP should only be delivered using a vaporizer specifically designed and designated for use with isoflurane. ( 2 ) • The administration of general anesthesia must be individualized and titrated based on the patient’s age and clinical status. ( 2 )
2.1Important Dosage and Administration Information Isoflurane should be administered only by persons trained in the administration of general anesthesia. Facilities for maintenance of a patent airway, artificial ventilation, oxygen enrichment, and circulatory resuscitation must be immediately available. Isoflurane is administered by inhalation.
Isoflurane should be delivered from a vaporizer specifically designed for use with isoflurane. Dosage for induction and maintenance must be individualized and titrated to the desired effect according to the patient’s age and clinical status. With the exception of neonates, the minimum alveolar concentration (MAC) of isoflurane decreases with increasing patient age.
Nitrous oxide decreases the MAC of isoflurane (see Table 1 ). Opioids decrease the MAC of isoflurane [see Drug Interactions (7) ]. Isoflurane potentiates the muscle relaxant effect of all neuromuscular blockers and decreases the required doses of neuromuscular blocking agents [see Drug Interactions (7) ] .
The dose should be adjusted accordingly. All patients anesthetized with isoflurane should be continually monitored (e.g., monitoring of the electrocardiogram, blood pressure, oxygen saturation, and end tidal CO 2 ). Isoflurane is a profound respiratory depressant.
Excessive respiratory depression may be related to depth of anesthesia and respond to decreasing the inspired concentration of isoflurane. The depressant effect is accentuated by concurrent use of opioids and other respiratory depressants. Respiration should be closely monitored and assisted or controlled ventilation employed when necessary.
2.2Premedication Premedication should be selected according to the need of the individual patient, taking into account that secretions are weakly stimulated by Isoflurane USP, and the heart rate tends to be increased.
2.3Induction Induction with isoflurane in oxygen or in combination with oxygen-nitrous oxide mixtures may produce coughing, breath holding, laryngospasm and bronchospasm, which increases with the concentration of isoflurane. These difficulties may be avoided by the use of a hypnotic dose of an ultra-short-acting barbiturate. Inspired concentrations of 1.5 to 3% isoflurane usually produce surgical anesthesia in 7 to 10 minutes.
2.4Maintenance Isoflurane MAC values according to age are shown below: Table 1: Effect of Age on Minimum Alveolar Concentration of Isoflurane Age Average MAC Value In 100% Oxygen Average MAC Value In 30% Oxygen and 70% N 2 O Preterm neonates less than 32 weeks gestational age 1.28% Preterm neonates 32-37 weeks gestational age 1.41% 0-1 month 1.60% 1-6 months 1.87% 6-12 months 1.80% 1-5 years 1.60% 6-10 years 1.45% 11-18 years 1.38% 19-30 years 1.28% 0.56% 31-55 years 1.15% 0.50% 55-83 years 1.05% 0.37% Dosage for induction and maintenance must be individualized and titrated to the desired effect according to the patient’s age and clinical status.
Surgical levels of anesthesia may be sustained with a 1 to 2.5% concentration when nitrous oxide is used concomitantly. An additional 0.5 to 1% may be required when isoflurane is given using oxygen alone. If added relaxation is required, supplemental doses of neuromuscular blocking agents may be used.
The level of blood pressure during maintenance is an inverse function of isoflurane concentration in the absence of other complicating problems. Excessive decreases may be due to depth of anesthesia and in such instances may be corrected by lightening anesthesia. Isoflurane causes a dose-dependent reduction in systemic vascular resistance and blood pressure.…
💊 Dosage Forms and Strengths ▾
3. DOSAGE FORMS AND STRENGTHS Isoflurane is a clear, colorless, stable liquid containing no additives or chemical stabilizers, 100% isoflurane. Liquid (stable): 100% ( 3 )
⛔ Contraindications ▾
4 CONTRAINDICATIONS Isoflurane USP is contraindicated in patients: • in whom general anesthesia is contraindicated. • with known sensitivity to Isoflurane USP or to other halogenated agents [see Warnings and Precautions ( 5.3 )]. • with known or suspected genetic susceptibility to malignant hyperthermia [see Warnings and Precautions ( 5.1 ), Clinical Pharmacology ( 12.5 )]. • with a history of confirmed hepatitis due to a halogenated inhalational anesthetic or a history of unexplained moderate to severe hepatic dysfunction (e.g., jaundice associated with fever and/or eosinophilia) after anesthesia with isoflurane or other halogenated inhalational anesthetics. • Patients in whom general anesthesia is contraindicated ( 4 ) • Patients with known sensitivity to Isoflurane USP or other halogenated agents ( 4 ) • Patients with known or suspected genetic susceptibility to malignant hyperthermia ( 4 ) • Patients with a history of confirmed hepatitis due to a halogenated inhalational anesthetic or a history of unexplained moderate to severe hepatic dysfunction (e.g., jaundice associated with fever and/or eosinophilia) after anesthesia with Isoflurane USP or other halogenated inhalational anesthetics ( 4 )
⚠️ Warnings and Cautions ▾
5 WARNINGS AND PRECAUTIONS • 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 ) • Hepatic Reactions : May cause sensitivity hepatitis in patients sensitized by previous exposure to halogenated anesthetics.
Approach repeated anesthesia with caution. ( 5.3 ) • Hypersensitivity Reactions : Allergic-type hypersensitivity reactions, including anaphylaxis, have been reported with isoflurane. ( 5.4 ) • Abortions : Increased blood loss comparable to that seen with halothane has been observed in patients undergoing abortions.
( 5.5 ) • QT Prolongation : Carefully monitor cardiac rhythm when administering Isoflurane USP to susceptible patients. ( 5.6 ) • 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 Isoflurane USP.
( 5.7 ) • 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. ( 5.8 )
5.1Malignant Hyperthermia In susceptible individuals, volatile anesthetic agents, including Isoflurane USP, 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.
Isoflurane USP 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 base derangements, and institution of measures to control rising temperature.
5.2Perioperative 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 el…
🤒 Adverse Reactions ▾
6 ADVERSE REACTIONS Most common adverse reactions (incidence > 5%) are agitation, cough, breath holding, nausea, chills/shivering, vomiting, laryngospasm, delirium. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Piramal Critical Care, Inc. at 1-888-822-8431or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
6.1Clinical Trials Experience The following adverse reactions were identified from controlled clinical trials of adult and pediatric subjects exposed to Isoflurane USP. The trials were conducted using a variety of pre-medications, other anesthetics, and surgical procedures of varying lengths. The most serious reported adverse reactions in alphabetical order are agitation, arrhythmia, breath holding, elevated liver enzyme, hypotension and laryngospasm.
The most frequent adverse reactions (incidence > 5%) described in Table 1 are agitation, breath holding, chills/shivering, cough, delirium, laryngospasm, nausea, and vomiting. Adverse reactions with an incidence between 1% and 5% are provided in Table 2 . Adverse reactions with an incidence less than 1% are provided in Table 3 .
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. Table 2: Adverse Reactions ≥ 5% System Organ Class (SOC) Adverse Reaction Frequency PSYCHIATRIC DISORDERS Delirium 6.2% (N=2830) NERVOUS SYSTEM DISORDERS Agitation (Excitement) Induction 51.8% (N=515) 1 RESPIRATORY, THORACIC, AND MEDIASTINAL DISORDERS Breath holding Induction 23.9% (N=515) 1 Cough Induction 28.2% (N=515) 1 Laryngospasm Induction 8.0% (N=515) 1 GASTROINTESTINAL DISORDERS Nausea Recovery 15.4 % (N=2830) Vomiting Recovery 9.5% (N=2830) GENERAL DISORDERS AND ADMINISTRATIVE SITE CONDITIONS Chills/shivering 14.0% (N=1691) 2 1 Represents patients not receiving intravenous agents or neuromuscular blocking agents for intubation (i.e., patients receiving inhalation induction).
2 Reflects the number of patients with recorded body temperature measurements. Table 3: Adverse Reactions between 1% and 5% System Organ Class (SOC) Adverse Reaction Frequency NERVOUS SYSTEM DISORDERS Movement Maintenance 1.8% (N=2830) CARDIAC DISORDERS Ventricular arrhythmia (Intraoperative) Induction 2.1% (N=2161) Maintenance 2.7% (N=2253) Nodal arrhythmia (Intraoperative) Induction 4.0% (N=2161) Maintenance 1.7% (N=2253) Atrial arrhythmia (Intraoperative) Induction 1.6% (N=2161 Maintenance 2.2% (N=2253) Arrhythmia (Postoperative) 1.1% (N=2830) RESPIRATORY, THORACIC, AND MEDIASTINAL DISORDERS Breath holding Maintenance 1.1% (N=359) 1 Cough Maintenance 4.2 % (N=359) 1 1 Represents patients not receiving intravenous agents or neuromuscular blocking agents for intubation (i.e., patients receiving inhalation induction).
Table 4: Adverse Reactions less than 1% System Organ Class (SOC) Adverse Reaction Frequency PSYCHIATRIC DISORDERS Mood changes 0.3% (N=2830) Nightmare 0.4% (N=2175) 1 NERVOUS SYSTEM DISORDERS Convulsive pattern on electroencephalogram 0.5% (N=200) 2 Seizure 0.04% (N=2830) VASCULAR DISORDERS Hypotension Postoperative 0.3% (N=2830) Hypertension Postoperative 0.1% (N=2830) RESPIRATORY, THORACIC, AND MEDIASTINAL DISORDERS Laryngospasm Maintenance 0.8% (N=359) 3 Secretions Induction 0.2% (N=515) 3 Maintenance 0.0% (N=359) 3 GASTROINTESTINAL DISORDERS Vomiting Induction 0.8% (N=515) 3 Retching Induction 1.0% (N=515) 3 Maintenance 0.8% (N=359) 3 SKIN AND SUBCUTANEOUS TISSUE DISORDERS Diaphoresis Induction 0.2% (N=515) 3 Maintenance 0.0% (N=359) 3 1 Reflects the number of patients interviewed by a physician in the recovery period.
2 Reflects the number of recorded electroencephalograms. 3 Represents patients not receiving intravenous agents or neuromuscular blocking agents for intubation (i.e., patients receiving inhalation induction). Table 5: Adverse Reactions with Unknown Frequency The following ad…
🔄 Drug Interactions ▾
7 DRUG INTERACTIONS • Concomitant use of N 2 O and/or opioids reduces the MAC of Isoflurane USP. Adjust dose accordingly. ( 7.1 , 7.2 ) • Isoflurane USP decreases the doses of neuromuscular blocking agents required. Adjust dose accordingly. ( 7.3 )
7.1Opioids Opioids decrease the Minimum Alveolar Concentration (MAC) of isoflurane. Opioids such as fentanyl and its analogues, when combined with isoflurane, may lead to a synergistic fall in blood pressure and respiratory rate.
7.2Nitrous Oxide Nitrous oxide decreases the MAC of isoflurane [see Dosage and Administration (2.1) ].
7.3Neuromuscular Blocking Agents Isoflurane potentiates the muscle relaxant effect of all neuromuscular blocking agents and decreases the required doses of neuromuscular blocking agents. In general, anesthetic concentrations isoflurane at equilibrium reduce the ED 95 of succinylcholine, atracurium, pancuronium, rocuronium and vecuronium by approximately 25 to 40% or more compared to N 2 O/opioid anesthesia. If added relaxation is required, supplemental doses of neuromuscular blocking agents may be used.
7.4Adrenaline Isoflurane is similar to sevoflurane in the sensitization of the myocardium to arrhythmogenic effect of exogenously administered adrenaline. Doses of adrenaline greater than 5mcg/kg, whenvadministered submucosally may produce multiple ventricular arrhythmias.
7.5Calcium Antagonists Isoflurane may lead to marked hypotension in patients treated with calcium antagonists.
7.6Concomitant use with Beta Blockers Concomitant use of beta blockers may exaggerate the cardiovascular effects of inhalational anesthetics, including hypotension and negative inotropic effects.
7.7Concomitant Use with MAO Inhibitors Concomitant use of MAO inhibitors and inhalational anesthetics may increase the risk of hemodynamic instability during surgery or medical procedures.
👥 Use in Specific Populations ▾
8 USE IN SPECIFIC POPULATIONS In the event of overdosage, or what may appear to be overdosage, the following action should be taken, as appropriate: Stop drug administration, establish a clear airway, and initiate assisted or controlled ventilation with pure oxygen. Monitor cardiovascular function and manage signs of poor end-organ perfusion as clinically indicated. Geriatric Use : The minimum alveolar concentration (MAC) of Isoflurane USP decreases with increasing patient age.
( 8.5 ) See 17 for PATIENT COUNSELING INFORMATION. Revised: 02/2025
8.1Pregnancy Risk Summary There are no adequate and well-controlled studies in pregnant women. In animal reproduction studies, embryofetal toxicity was noted in pregnant mice exposed to 0.075% (increased post implantation losses) and 0.3% isoflurane (increased post implantation losses and decreased livebirth index) 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. Data Animal Data Pregnant rats were exposed to isoflurane at concentrations of 0%, 0.1%, or 0.4% for two hours per day during organogenesis (Gestational Days 6-15). Isoflurane did not cause malformations or clear maternal toxicity under these conditions.
Pregnant mice exposed to isoflurane at concentrations of 0%, 0.075%, or 0.30% for 2 hours per day during organogenesis (Gestational Days 6-15). Isoflurane increased fetal toxicity (higher post implantation losses at 0.075 and 0.3% groups and significantly lower live-birth index in the 0.3% isoflurane treatment group). Isoflurane did not cause malformations or clear maternal toxicity under these conditions.
Pregnant rats were exposed to concentrations of isoflurane at 0%, 0.1%, or 0.4% for 2 hours per day during late gestation (GD 15-20). Animals appeared slightly sedated during exposure. No adverse effects on the offspring or evidence of maternal toxicity were reported.
This study did not evaluate neurobehavioral function including learning and memory in the first generation (F1) of 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 (5.8) , Nonclinical Toxicology (13.2) ].
8.2Lactation Due to insufficient information regarding the excretion of isoflurane in human milk, the potential risks and benefits for each specific patient should be carefully considered before isoflurane is administered to nursing women.
8.4Pediatric Use During the induction of anesthesia, saliva flow and tracheobronchial secretion can increase and can be the cause of larynogospasm, particularly in children. Published juvenile animal studies demonstrate that the administration of anes…
🤰 Pregnancy ▾
8.1Pregnancy Risk Summary There are no adequate and well-controlled studies in pregnant women. In animal reproduction studies, embryofetal toxicity was noted in pregnant mice exposed to 0.075% (increased post implantation losses) and 0.3% isoflurane (increased post implantation losses and decreased livebirth index) 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. Data Animal Data Pregnant rats were exposed to isoflurane at concentrations of 0%, 0.1%, or 0.4% for two hours per day during organogenesis (Gestational Days 6-15). Isoflurane did not cause malformations or clear maternal toxicity under these conditions.
Pregnant mice exposed to isoflurane at concentrations of 0%, 0.075%, or 0.30% for 2 hours per day during organogenesis (Gestational Days 6-15). Isoflurane increased fetal toxicity (higher post implantation losses at 0.075 and 0.3% groups and significantly lower live-birth index in the 0.3% isoflurane treatment group). Isoflurane did not cause malformations or clear maternal toxicity under these conditions.
Pregnant rats were exposed to concentrations of isoflurane at 0%, 0.1%, or 0.4% for 2 hours per day during late gestation (GD 15-20). Animals appeared slightly sedated during exposure. No adverse effects on the offspring or evidence of maternal toxicity were reported.
This study did not evaluate neurobehavioral function including learning and memory in the first generation (F1) of 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 (5.8) , Nonclinical Toxicology (13.2) ].
🧒 Pediatric Use ▾
8.4Pediatric Use During the induction of anesthesia, saliva flow and tracheobronchial secretion can increase and can be the cause of larynogospasm, particularly in children. Published juvenile animal studies demonstrate that the administration of anesthetic and sedation drugs, such as Isoflurane USP, 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 (5.8) , Nonclinical Toxicology (13.2) ].
🧓 Geriatric Use ▾
8.5Geriatric Use The minimum alveolar concentration (MAC) of isoflurane decreases with increasing patient age. The dose should be adjusted accordingly [see Dosage and Administration (2.4) ].
🆘 Overdosage ▾
10 OVERDOSAGE The symptoms of overdosage of Isoflurane USP can present as a deepening of anesthesia, cardiac and/or respiratory depression in spontaneously breathing patients, and cardiac depression in ventilated patients in whom hypercapnia and hypoxia may occur only at a late stage. In the event of overdosage, or what may appear to be overdosage, the following action should be taken, as appropriate: Stop drug administration, establish a clear airway, and initiate assisted or controlled ventilation with pure oxygen.
Monitor cardiovascular function and manage signs of poor end-organ perfusion as clinically indicated.
🧬 Clinical Pharmacology ▾
12 CLINICAL PHARMACOLOGY
12.2Pharmacodynamics Induction of and recovery from isoflurane anesthesia are rapid. Isoflurane has a mild pungency which limits the rate of induction, although excessive salivation or tracheobronchial secretions do not appear to be stimulated. Pharyngeal and laryngeal reflexes are readily obtunded.
The level of anesthesia may be changed rapidly with isoflurane. Isoflurane is a profound respiratory depressant. As anesthetic dose is increased, tidal volume decreases and respiratory rate is unchanged.
This depression is partially reversed by surgical stimulation, even at deeper levels of anesthesia. Isoflurane evokes a sigh response reminiscent of that seen with diethyl ether and enflurane, although the frequency is less than with enflurane. Blood pressure decreases with induction of anesthesia but returns toward normal with surgical stimulation.
Progressive increases in depth of anesthesia produce corresponding decreases in blood pressure. Nitrous oxide diminishes the inspiratory concentration of isoflurane required to reach a desired level of anesthesia and may reduce the arterial hypotension seen with isoflurane alone. Heart rhythm is remarkably stable.
With controlled ventilation and normal PaCO 2 , cardiac output is maintained despite increasing depth of anesthesia, primarily through an increase in heart rate which compensates for a reduction in stroke volume. The hypercapnia which attends spontaneous ventilation during isoflurane anesthesia further increases heart rate and raises cardiac output above awake levels. Muscle relaxation is often adequate for intra-abdominal operations at normal levels of anesthesia.
Complete muscle paralysis can be attained with small doses of neuromuscular blocking agents. ALL COMMONLY USED NEUROMUSCULAR BLOCKING AGENTS ARE MARKEDLY POTENTIATED WITH ISOFLURANE, THE EFFECT BEING MOST PROFOUND WITH THE NONDEPOLARIZING TYPE. Neostigmine reverses the effect of nondepolarizing neuromuscular blocking agents in the presence of isoflurane.
All commonly used neuromuscular blocking agents are compatible with isoflurane. Isoflurane can produce coronary vasodilation at the arteriolar level in selected animal models; the drug is probably also a coronary dilator in humans. Isoflurane, like some other coronary arteriolar dilators, has been shown to divert blood from collateral dependent myocardium to normally perfused areas in an animal model (“coronary steal”).
Clinical trials to date evaluating myocardial ischemia, infarction and death as outcome parameters have not established that the coronary arteriolar dilation property of isoflurane is associated with coronary steal or myocardial ischemia in patients with coronary artery disease.
12.3Pharmacokinetics Isoflurane undergoes minimal biotransformation in man. In the postanesthesia period, only 0.17% of the isoflurane taken up can be recovered as urinary metabolites.
12.5Pharmacogenomics RYR1 and CACNA1S are polymorphic genes, and multiple pathogenic variants have been associated with malignant hyperthermia susceptibility (MHS) in patients receiving volatile anesthetic agents, including Isoflurane USP. Case reports as well as ex-vivo studies have identified multiple variants in RYR1 and CACNA1S associated with MHS. Variant pathogenicity should be assessed based on prior clinical experience, functional studies, prevalence information, or other evidence [see Contraindications (4) , Warnings and Precautions (5.1) ].
📦 How Supplied / Storage and Handling ▾
16 HOW SUPPLIED/STORAGE AND HANDLING Isoflurane USP, is available in the following presentations: FILL CONTAINER NDC 100 mL Amber-colored Bottle 66794-017-10 250 mL Amber-colored Bottle 66794-017-25 Replace the cap securely after each use.
16.1Safety and Handling Occupational Caution The following reactions have been reported following occupational exposure to isoflurane: dyspnea, bronchospasm, stridor, cough, dizziness, paresthesia, hepatic reactions, flushing rash, contact dermatitis, erythema, periorbital edema, eye irritation, conjunctival hyperemia, and headache. There is no specific work exposure limit established for Isoflurane USP. However, the National Institute for Occupational Safety and Health Administration (NIOSH) recommends that no worker should be exposed at ceiling concentrations greater than 2 ppm of any halogenated anesthetic agent over a sampling period not to exceed one hour.
The predicted effects of acute overexposure by inhalation of Isoflurane USP include headache, dizziness or (in extreme cases) unconsciousness [see Overdosage (10) ]. There are no documented adverse effects of chronic exposure to halogenated anesthetic vapors (Waste Anesthetic Gases or WAGs) in the workplace. Although results of some epidemiological studies suggest a link between exposure to halogenated anesthetics and increased health problems (particularly spontaneous abortion), the relationship is not conclusive.
Since exposure to WAGs is one possible factor in the findings for these studies, operating room personnel, and pregnant women in particular, should minimize exposure. Precautions include adequate general ventilation in the operating room, the use of a well-designed and well-maintained scavenging system, work practices to minimize leaks and spills while the anesthetic agent is in use, and routine equipment maintenance to minimize leaks.
16.2Storage Store at 20°-25°C (68°-77°F); excursions permitted to 15°-30°C (59°-86°F) [see USP Controlled Room Temperature]. Isoflurane contains no additives and has been demonstrated to be stable at room temperature for periods in excess of five years.
📦 Storage and Handling ▾
16.1Safety and Handling Occupational Caution The following reactions have been reported following occupational exposure to isoflurane: dyspnea, bronchospasm, stridor, cough, dizziness, paresthesia, hepatic reactions, flushing rash, contact dermatitis, erythema, periorbital edema, eye irritation, conjunctival hyperemia, and headache. There is no specific work exposure limit established for Isoflurane USP. However, the National Institute for Occupational Safety and Health Administration (NIOSH) recommends that no worker should be exposed at ceiling concentrations greater than 2 ppm of any halogenated anesthetic agent over a sampling period not to exceed one hour.
The predicted effects of acute overexposure by inhalation of Isoflurane USP include headache, dizziness or (in extreme cases) unconsciousness [see Overdosage (10) ]. There are no documented adverse effects of chronic exposure to halogenated anesthetic vapors (Waste Anesthetic Gases or WAGs) in the workplace. Although results of some epidemiological studies suggest a link between exposure to halogenated anesthetics and increased health problems (particularly spontaneous abortion), the relationship is not conclusive.
Since exposure to WAGs is one possible factor in the findings for these studies, operating room personnel, and pregnant women in particular, should minimize exposure. Precautions include adequate general ventilation in the operating room, the use of a well-designed and well-maintained scavenging system, work practices to minimize leaks and spills while the anesthetic agent is in use, and routine equipment maintenance to minimize leaks.
16.2Storage Store at 20°-25°C (68°-77°F); excursions permitted to 15°-30°C (59°-86°F) [see USP Controlled Room Temperature]. Isoflurane contains no additives and has been demonstrated to be stable at room temperature for periods in excess of five years.
📋 Description ▾
11 DESCRIPTION Isoflurane USP (isoflurane, USP), a nonflammable liquid administered by vaporizing, is a general inhalation anesthetic drug. It is 1-chloro-2,2,2-trifluoroethyl difluoromethyl ether, and its structural formula is: Some physical constants are: Molecular weight 184.5 Boiling point at 760 mm Hg 48.5°C Refractive index n 20/D 1.2990-1.3005 Specific gravity 25°/25°C 1.496 Vapor pressure in mm Hg** 20°C 238 25°C 295 30°C 367 35°C 450 **Equation for vapor pressure calculation: log 10 Pvap = A + B/T where: A = 8.056 B=−1664.58 T = °C + 273.16 (Kelvin) Partition coefficients at 37°C Water/gas
0.61 Blood/gas
1.43 Oil/gas
90.8 Partition coefficients at 25°C – rubber and plastic Conductive rubber/gas
62.0 Butyl rubber/gas
75.0Polyvinyl chloride/gas 110.0 Polyethylene/gas ~2.0 Polyurethane/gas ~1.4 Polyolefin/gas ~1.1 Butyl acetate/gas ~2.5 Purity by gas chromatography >99.9% Lower limit of flammability in oxygen or nitrous oxide at 9 joules/sec. and 23°C None Lower limit of flammability in oxygen or nitrous oxide at 900 joules/sec. and 23°C Greater than useful concentration in anesthesia. Isoflurane is a clear, colorless, stable liquid containing no additives or chemical stabilizers. Isoflurane has a mildly pungent, musty, ethereal odor.
Samples stored in indirect sunlight in clear, colorless glass for five years, as well as samples directly exposed for 30 hours to a 2 amp, 115 volt, 60 cycle long wave U.V. light were unchanged in composition as determined by gas chromatography. Isoflurane in one normal sodium methoxide-methanol solution, a strong base, for over six months consumed essentially no alkali, indicative of strong base stability. Isoflurane does not decompose in the presence of soda lime (at normal operating temperatures), and does not attack aluminum, tin, brass, iron or copper. isoflurane