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forane

Forane (Isoflurane) is a general anesthetic used to treat Depressive Disorder, Status Asthmaticus.

Isoflurane · by Baxter Hlthcare

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Rated against independent regulatory sources·Last updated June 7, 2026·How we rate
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Key facts

Active ingredient
Isoflurane
Form
Spray/Inhaler
Strength
Isoflurane 99.9%
Type
Prescription (Rx)
Brand or generic
Brand-name
Manufacturer
Baxter Hlthcare
FDA application
NDA017624

What is Forane?

From the FDA label:FORANE (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 P vap = 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 75.0 Polyvinyl 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…

How to use

FORANE should be administered only by persons trained in the administration of general anesthesia. FORANE 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 ) 2.1 Important Dosage and Administration Information FORANE 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. FORANE is administered by inhalation. FORANE should be delivered from a vaporizer specifically designed for use with FORANE. 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 FORANE (see Table 1 ). Opioids decrease the MAC of FORANE [see Drug Interactions (7) ] . FORANE 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…

Side effects

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 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 The following adverse reactions were identified from controlled clinical trials of adult and pediatric subjects exposed to FORANE. 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)…

Warnings

Important safety information

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 FORANE. ( 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 FORANE 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 FORANE. ( 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 ) 5.1 Malignant Hyperthermia In susceptible individuals, volatile anesthetic agents, including FORANE, 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. FORANE 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. 5.2 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 Hepatic Reactions Cases of mild, moderate and severe postoperative hepatic dysfunction or hepatitis with or without jaundice, including fatal hepatic necrosis and hepatic failure, have been reported with FORANE. Such reactions can represent hypersensitivity hepatitis, a known risk of exposure to halogenated anesthetics, including FORANE. As with other halogenated anesthetic agents, FORANE may cause sensitivity hepatitis in patients who have been sensitized by previous exposure to halogenated anesthetics [see Contraindications (4) ] . Clinical judgment should be exercised when FORANE is used in patients with underlying hepatic conditions or under treatment with drugs known to cause hepatic dysfunction [see Contraindications (4) ] . As with all halogenated anesthetics, repeated anesthetics within a short period of time may result in increased effects, particularly in patients with underlying hepatic conditions, or additive effects in patients treated with drugs known to cause hepatic dysfunction. Evaluate the need for repeated exposure in each individual patient and adjust the dose of FORANE based on signs and symptoms of adequate depth of anesthesia if repeated exposure in a short period of time is clinically indicated. 5.4 Hypersensitivity Reactions Allergic-type hypersensitivity reactions, including anaphylaxis, have been reported with FORANE. Manifestations of such reactions have included hypotension, rash, difficulty breathing and cardiovascular collapse 5.5 Abortions Increased blood loss comparable to that seen with halothane has been observed in patients undergoing abortions. 5.6 QT Prolongation QT prolongation, with rare instances of torsade de pointes, have been reported. Monitor QT interval when administering FORANE to susceptible patients (e.g., patients with congenital Long QT Syndrome or patients taking drugs that can prolong the QT interval). 5.7 Interactions with Desiccated Carbon Dioxide Absorbents FORANE, like some other inhalational anesthetics, can react with desiccated carbon dioxide (CO 2 ) absorbents to produce carbon monoxide, which may result in elevated levels of carboxyhemoglobin in some patients. Barium hydroxide lime and soda lime become desiccated when fresh gases are passed through the CO 2 absorber 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 FORANE. The color indicator of most CO 2 absorbents does not necessarily change as a result of desiccation. Therefore, the lack of significant color change should not be taken as assurance of adequate hydration of the CO 2 absorbent material. CO 2 absorbents should be replaced routinely regardless of the state of color indicator following current manufacturer’s guidelines for use of anesthesiology equipment. 5.8 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) ] . Some published studies in children suggest that similar…

Who should not take Forane

FORANE is contraindicated in patients: • in whom general anesthesia is contraindicated. • with known sensitivity to FORANE 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 FORANE 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 FORANE or other halogenated inhalational anesthetics ( 4 )

Overdose — what happens if you take too much

The symptoms of overdosage of FORANE 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.

U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.

Interactions

Concomitant use of N 2 O and/or opioids reduces the MAC of FORANE. Adjust dose accordingly. ( 7.1 , 7.2 ) • FORANE decreases the doses of neuromuscular blocking agents required. Adjust dose accordingly. ( 7.3 ) 7.1 Opioids Opioids decrease the Minimum Alveolar Concentration (MAC) of FORANE. Opioids such as fentanyl and its analogues, when combined with FORANE, may lead to a synergistic fall in blood pressure and respiratory rate. 7.2 Nitrous Oxide Nitrous oxide decreases the MAC of FORANE [see Dosage and Administration (2.1) ] . 7.3 Neuromuscular Blocking Agents FORANE potentiates the muscle relaxant effect of all neuromuscular blocking agents and decreases the required doses of neuromuscular blocking agents. In general, anesthetic concentrations of FORANE 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. 7.4 Adrenaline FORANE is similar to sevoflurane in the sensitization of the myocardium to arrhythmogenic effect of exogenously administered adrenaline. Doses of adrenaline greater than 5mcg/kg, when administered submucosally may produce multiple ventricular arrhythmias. 7.5 Calcium Antagonists FORANE may lead to marked hypotension in patients treated with calcium antagonists. 7.6 Concomitant Use with Beta Blockers Concomitant use of beta blockers may exaggerate the cardiovascular effects of inhalational anesthetics, including hypotension and negative inotropic effects. 7.7 Concomitant Use with MAO Inhibitors Concomitant use of MAO inhibitors and inhalational anesthetics may increase the risk of hemodynamic instability during surgery or medical procedures.

Drug class

How this class works, per Isoflurane - StatPearls - NCBI Bookshelf.

May treat (source: NIH RxClass)

Dosage forms

Spray/Inhaler

The forms currently marketed in the U.S., per the FDA National Drug Code Directory.

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Frequently asked questions

What does Forane treat?
Forane (Isoflurane) may be used to treat depressive disorder, status asthmaticus, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
How does Forane work?
Forane is a general anesthetic. General anesthetics produce reversible unconsciousness by altering the brain's chemical signaling: they boost the activity of calming GABA receptors while dampening excitatory NMDA receptors. This tips the brain into a deeply sedated state that prevents awareness, memory, and pain during surgery.
Is there a coupon or discount for Forane?
pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Forane. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
Who makes Forane?
Forane is marketed by Baxter Hlthcare. You can see Baxter Hlthcare's full profile, rating, and other products on pharmaranks.
Is Forane a brand-name or generic drug?
Forane is a brand-name product with the active ingredient Isoflurane.
Is Forane available over the counter?
No. Forane is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
What forms does Forane come in?
Forane is currently marketed as spray/inhaler, per the FDA's National Drug Code Directory.
What class of drug is Forane?
Forane is classified as general anesthetic, per the FDA's Established Pharmacologic Class.
Is Forane FDA-registered?
Forane is on record with the U.S. FDA under application number NDA017624. You can verify this on its official FDA label.
Is Forane safe?
There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Forane. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
What are the side effects of Forane?
Forane's side effects are taken directly from its FDA label. From the label: 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 Baxter Healthcare Corporation at 1-800-262-3784 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.

Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.

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