Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ISOFLURANE vs SUPRANE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Isoflurane is a general inhalation anesthetic that acts as a positive allosteric modulator of GABA-A receptors and glycine receptors, and inhibits excitatory receptors such as NMDA and AMPA receptors. It potentiates inhibitory neurotransmission and depresses excitatory neurotransmission, leading to anesthesia, amnesia, and muscle relaxation.
Suprane (desflurane) is a volatile general anesthetic that potentiates GABA-A receptor activity and inhibits NMDA receptor function, leading to neuronal hyperpolarization and depression of central nervous system activity.
Induction and maintenance of general anesthesia,Sedation in mechanically ventilated patients (off-label)
Induction and maintenance of general anesthesia for inpatient and outpatient surgery in adults and children,Maintenance of anesthesia in pediatric patients
Induction: 1-3% in oxygen or oxygen/nitrous oxide mixture via inhalation; Maintenance: 0.5-2% in oxygen or oxygen/nitrous oxide mixture via inhalation.
Induction: 0.5-3% inspired concentration in oxygen or oxygen/nitrous oxide mixture; Maintenance: 0.5-2% inspired concentration. Administered via inhalation using a calibrated vaporizer.
Terminal elimination half-life is approximately 2.5 to 5 hours. Context: The context-sensitive half-time varies with duration of anesthesia; for short procedures (<1 hour), half-life is about 2-4 minutes, but for prolonged anesthesia, it can be 30-60 minutes due to redistribution from fat stores.
Context-sensitive half-life: 2-5 minutes after brief administration; prolonged to 20-40 minutes after prolonged administration due to slow release from fat stores.
Isoflurane undergoes minimal metabolism (approximately 0.2%) primarily via hepatic cytochrome P450 enzymes (CYP2E1), leading to the production of inorganic fluoride and trifluoroacetic acid. The major route of elimination is via exhalation as unchanged drug.
Minimal hepatic metabolism (less than 0.02%) via CYP2E1; primarily eliminated unchanged by the lungs.
Primarily eliminated via exhalation through the lungs (>99%). Less than 1% undergoes hepatic metabolism to trifluoroacetic acid and fluoride ions, which are excreted renally.
Primarily eliminated by the lungs with minimal metabolism (<5%). Less than 0.2% of the absorbed dose is excreted renally as unchanged drug.
Approximately 5-20% bound to plasma proteins, primarily albumin.
~60% bound to serum proteins, primarily albumin and lipoproteins.
Volume of distribution is about 2-5 L/kg, reflecting extensive tissue distribution, especially to lipid-rich tissues like brain and fat.
Vd: 0.6-0.8 L/kg at steady state; large distribution into lipid-rich tissues.
Inhalation: Bioavailability is essentially 100% for inspired drug; systemic absorption is nearly complete due to rapid pulmonary exchange.
Inhalation: ~100% due to complete absorption from the lungs; no oral bioavailability is clinically relevant.
No dose adjustment required in renal impairment; pharmacokinetics unaffected.
No dose adjustment required for renal impairment; Suprane is minimally metabolized and renally excreted.
No specific dose adjustment guidelines; use with caution in severe hepatic impairment due to potential for hepatotoxicity.
No specific dose adjustment for Child-Pugh class A or B; caution in severe hepatic impairment (Child-Pugh C) due to potential decreased clearance, consider reduced maintenance concentrations.
Induction: 1.5-3% in oxygen or oxygen/nitrous oxide mixture; Maintenance: 0.5-2% in oxygen or oxygen/nitrous oxide mixture; titrate to effect.
Induction: 3% inspired concentration in oxygen (or oxygen/nitrous oxide) for unpremedicated children, titrated to effect; Maintenance: 1-2% inspired concentration. Adjust based on age and response.
Reduce concentrations by 20-50% due to increased sensitivity and decreased MAC; monitor hemodynamics closely.
Elderly patients (≥65 years): Reduce induction and maintenance concentrations by 20-50% due to increased sensitivity and slower recovery; typical maintenance 0.5-1.5% inspired.
Because isoflurane is a potent halogenated anesthetic, it may cause malignant hyperthermia, a life-threatening condition characterized by hypermetabolism, muscle rigidity, tachycardia, and hyperthermia. Immediate treatment with dantrolene and discontinuation of triggering agents is essential.
Suprane is contraindicated for induction of anesthesia in pediatric patients due to a high incidence of laryngospasm, coughing, breath-holding, and hypoxia.
Risk of malignant hyperthermia,Respiratory depression,Hypotension and myocardial depression,Elevated intracranial pressure,Hepatic injury (rare),Nephrotoxicity due to fluoride ion (rare),QT interval prolongation,Use with caution in patients with coronary artery disease
Risk of malignant hyperthermia,Risk of perioperative hypersensitivity reactions including anaphylaxis,Risk of QT prolongation and torsades de pointes,Risk of hepatotoxicity in patients with previous exposure to halogenated anesthetics,May cause dose-dependent respiratory depression,Use caution in patients with increased intracranial pressure,May cause hypotension and bradycardia
Known or suspected susceptibility to malignant hyperthermia,Prior history of unexplained jaundice or fever after isoflurane administration,Concurrent use of entacapone (increased risk of intraoperative myocardial depression)
Known or suspected susceptibility to malignant hyperthermia,Known hypersensitivity to desflurane or other halogenated anesthetics,Induction of anesthesia in pediatric patients,Patients with a history of hepatitis or unexplained jaundice after previous halogenated anesthetic use
No specific food interactions with isoflurane. However, fasting before anesthesia is required to reduce the risk of pulmonary aspiration.
No direct food interactions; fasting is required before anesthesia (typically NPO for 6-8 hours for solids, 2 hours for clear liquids) to reduce aspiration risk during induction.
Isoflurane is not associated with major congenital malformations but may cause fetal depression, especially during third trimester. Avoid elective use until after delivery.
Sevoflurane (Suprane) is classified as FDA Pregnancy Category B. Animal studies have not demonstrated teratogenic effects, but there are no adequate and well-controlled studies in pregnant women. Use in the first trimester should be avoided unless essential. In the second and third trimesters, it is used for general anesthesia; however, it may produce uterine relaxation and fetal depression. Prolonged or repeated exposure should be avoided due to potential neurotoxicity in the developing fetus.
Minimal transfer into breast milk; M/P ratio unknown. Considered compatible with breastfeeding after single exposure; observe infant for sedation.
Sevoflurane is rapidly eliminated; trace amounts may be excreted into breast milk. The M/P ratio is not established. Due to rapid clearance, the risk to the infant is low. The manufacturer recommends discontinuing breastfeeding for 24 hours after anesthesia to minimize exposure.
No dose adjustment required for pregnancy per se; however, MAC decreases by about 25-40% during pregnancy due to hormonal changes and increased progesterone. Use lowest effective dose.
No specific dose adjustments are recommended for sevoflurane during pregnancy. Pharmacokinetic changes in pregnancy (e.g., increased volume of distribution, decreased protein binding) may require higher induction doses and more rapid adjustments. Maintenance doses should be titrated to effect with careful monitoring of maternal vital signs and fetal heart rate.
Isoflurane is a halogenated ether anesthetic. It causes dose-dependent hypotension primarily through vasodilation. It is not recommended for induction in pediatrics due to pungency and airway irritability. Malignant hyperthermia trigger. Use with caution in patients with elevated intracranial pressure as it can increase cerebral blood flow. Monitor end-tidal CO2 and volatile agent concentration.
Suprane (desflurane) has a low blood-gas partition coefficient (0.42) enabling rapid induction and emergence. It is a potent bronchodilator but can cause airway irritation and coughing during induction; avoid in pediatric mask inductions. Contraindicated in patients with known or suspected malignant hyperthermia susceptibility. Requires a calibrated vaporizer due to high vapor pressure (near-ambient). Can produce dose-dependent hypotension and respiratory depression.
You will receive isoflurane gas to keep you asleep and pain-free during surgery.,You may experience shivering or nausea after awakening; tell your nurse if severe.,Do not eat or drink for the time instructed before surgery to prevent aspiration.,If you have a personal or family history of malignant hyperthermia, inform your anesthesiologist immediately.,Arrange for a ride home after surgery as isoflurane can impair coordination and judgment for up to 24 hours.
You will be given this anesthetic gas through a mask or breathing tube to keep you asleep during surgery.,You may experience a temporary sore throat or cough after waking up.,Common side effects include nausea, vomiting, and shivering as you recover.,You should not drive or operate machinery for at least 24 hours after anesthesia.,Inform your doctor if you have any personal or family history of malignant hyperthermia.
"Telithromycin, a macrolide antibiotic, prolongs the QT interval by blocking the rapid component of the delayed rectifier potassium current (IKr). Isoflurane, a volatile anesthetic, also prolongs the QT interval via inhibition of IKr and other cardiac ion channels. The combination may lead to additive or synergistic QT prolongation, increasing the risk of torsades de pointes, a potentially fatal ventricular arrhythmia, especially in patients with other risk factors such as hypokalemia, bradycardia, or pre-existing cardiac disease."
"Isoflurane, a volatile halogenated anesthetic, potentiates the cardiodepressant and arrhythmogenic effects of levobupivacaine, a long-acting amide local anesthetic, by inhibiting myocardial calcium channels and β-adrenergic responsiveness. This additive negative inotropic and chronotropic effect increases the risk of hypotension, bradycardia, and potentially life-threatening ventricular arrhythmias during combined use. Additionally, isoflurane may delay levobupivacaine metabolism by reducing hepatic blood flow, prolonging systemic exposure and toxicity."
"The combination of isoflurane and thiamylal results in synergistic CNS depression and enhanced negative inotropic and vasodilatory effects on the cardiovascular system. Isoflurane potentiates the barbiturate-induced suppression of myocardial contractility and baroreceptor reflexes, leading to a heightened risk of hypotension, bradycardia, and reduced cardiac output. Clinically, patients may experience profound anesthesia, prolonged recovery, and hemodynamic instability, especially during induction and maintenance of anesthesia."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ISOFLURANE vs SUPRANE, answered by our medical review team.
ISOFLURANE is a Inhalational Anesthetic that works by Isoflurane is a general inhalation anesthetic that acts as a positive allosteric modulator of GABA-A receptors and glycine receptors, and inhibits excitatory receptors such as NMDA and AMPA receptors. It potentiates inhibitory neurotransmission and depresses excitatory neurotransmission, leading to anesthesia, amnesia, and muscle relaxation.. SUPRANE is a Inhalational Anesthetic that works by Suprane (desflurane) is a volatile general anesthetic that potentiates GABA-A receptor activity and inhibits NMDA receptor function, leading to neuronal hyperpolarization and depression of central nervous system activity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ISOFLURANE and SUPRANE depend on the specific clinical indication. These are both Inhalational Anesthetic agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ISOFLURANE is: Induction: 1-3% in oxygen or oxygen/nitrous oxide mixture via inhalation; Maintenance: 0.5-2% in oxygen or oxygen/nitrous oxide mixture via inhalation.. The standard adult dose of SUPRANE is: Induction: 0.5-3% inspired concentration in oxygen or oxygen/nitrous oxide mixture; Maintenance: 0.5-2% inspired concentration. Administered via inhalation using a calibrated vaporizer.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ISOFLURANE and SUPRANE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ISOFLURANE is classified as Category C. Isoflurane is not associated with major congenital malformations but may cause fetal depression, especially during third trimester. Avoid elective use until after delivery.. SUPRANE is classified as Category C. Sevoflurane (Suprane) is classified as FDA Pregnancy Category B. Animal studies have not demonstrated teratogenic effects, but there are no adequate and well-controlled studies in . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.