isoflurane (Rx)

Brand and Other Names:Forane
  • Print

Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

inhalation solution

  • 100mL
  • 250mL

Anesthesia Induction & Maintenance

Use calibrated vaporizer

Induction: 1.5-3% can produce surgical anesthesia in 7-10 minutes

Maintenance: 1-2.5% with nitrous oxide

Additional 0.5-1% may be needed if given with oxygen alone

Safety & efficacy not established

Next:

Interactions

Interaction Checker

and isoflurane

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

            All Interactions Sort By:
             activity indicator 

            Contraindicated (0)

              Serious - Use Alternative (34)

              • benzhydrocodone/acetaminophen

                benzhydrocodone/acetaminophen, isoflurane. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

              • dexfenfluramine

                isoflurane increases toxicity of dexfenfluramine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • dexmethylphenidate

                isoflurane increases toxicity of dexmethylphenidate by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • dextroamphetamine

                isoflurane increases toxicity of dextroamphetamine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • diethylpropion

                isoflurane increases toxicity of diethylpropion by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • dobutamine

                isoflurane increases toxicity of dobutamine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • dopamine

                isoflurane increases toxicity of dopamine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • ephedrine

                isoflurane increases toxicity of ephedrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • epinephrine

                isoflurane increases toxicity of epinephrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • fenfluramine

                isoflurane increases toxicity of fenfluramine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • fentanyl

                fentanyl, isoflurane. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

              • fentanyl intranasal

                fentanyl intranasal, isoflurane. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

              • fentanyl transdermal

                fentanyl transdermal, isoflurane. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

              • fentanyl transmucosal

                fentanyl transmucosal, isoflurane. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

              • fexinidazole

                fexinidazole and isoflurane both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.

              • hydrocodone

                hydrocodone, isoflurane. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

              • isoproterenol

                isoflurane increases toxicity of isoproterenol by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • lefamulin

                lefamulin and isoflurane both increase QTc interval. Avoid or Use Alternate Drug.

              • lisdexamfetamine

                isoflurane increases toxicity of lisdexamfetamine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • mefloquine

                mefloquine increases toxicity of isoflurane by QTc interval. Avoid or Use Alternate Drug. Mefloquine may enhance the QTc prolonging effect of high risk QTc prolonging agents.

              • methamphetamine

                isoflurane increases toxicity of methamphetamine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • methylphenidate

                isoflurane increases toxicity of methylphenidate by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of acute hypertensive episode.

              • metoclopramide intranasal

                isoflurane, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.

              • midodrine

                isoflurane increases toxicity of midodrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • norepinephrine

                isoflurane increases toxicity of norepinephrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • phendimetrazine

                isoflurane increases toxicity of phendimetrazine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • phentermine

                isoflurane increases toxicity of phentermine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • phenylephrine

                isoflurane increases toxicity of phenylephrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • phenylephrine PO

                isoflurane increases toxicity of phenylephrine PO by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • propylhexedrine

                isoflurane increases toxicity of propylhexedrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • pseudoephedrine

                isoflurane increases toxicity of pseudoephedrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • sufentanil SL

                sufentanil SL, isoflurane. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

              • xylometazoline

                isoflurane increases toxicity of xylometazoline by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              • yohimbine

                isoflurane increases toxicity of yohimbine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.

              Monitor Closely (12)

              • benazepril

                isoflurane, benazepril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Increases risk of hypotension.

              • brexanolone

                brexanolone, isoflurane. Either increases toxicity of the other by sedation. Use Caution/Monitor.

              • buprenorphine, long-acting injection

                isoflurane increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

              • captopril

                isoflurane, captopril. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Both drugs lower blood pressure. Monitor blood pressure.

              • esketamine intranasal

                esketamine intranasal, isoflurane. Either increases toxicity of the other by sedation. Use Caution/Monitor.

              • fostemsavir

                isoflurane and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

              • lasmiditan

                lasmiditan, isoflurane. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.

              • lemborexant

                lemborexant, isoflurane. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.

              • midazolam intranasal

                midazolam intranasal, isoflurane. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

              • oliceridine

                oliceridine, isoflurane. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

              • osilodrostat

                osilodrostat and isoflurane both increase QTc interval. Use Caution/Monitor.

              • stiripentol

                stiripentol, isoflurane. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.

              Minor (0)

                Previous
                Next:

                Adverse Effects

                1-10%

                Nausea

                Vomiting

                Shivering

                <1%

                Dose-dependent hypotension

                Arrhythmias

                Malignant hyperthermia (rare)

                Elevations in white blood count

                May decrease creatinine and increase BUN

                Ileus, severe (fatal)

                Hepatic dysfunction (postoperative period) (rare)

                Respiratory depression may occur (rare)

                Previous
                Next:

                Warnings

                Contraindications

                Hypersensitivity to isoflurane & halogenated agents

                Genetic susceptibility to malignant hyperthermia

                Cautions

                Caution in coronary heart disease

                May decrease renal and hepatic blood flow

                Postoperative hepatic dysfunction and hepatitis reported

                Rare risk of perioperative hyperkalemia & malignant hyperthermia

                Adequate data have not been developed to establish its application in obstetrical anesthesia

                Should not be used as a sole agent of induction in patients with ventricular dysfunction

                Perioperative Hyperkalemia

                • Inhaled anesthetics associated with rare increases in serum potassium levels that have resulted in cardiac arrhythmias and death in pediatric patients postoperatively
                • 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
                • Elevated serum creatinine kinase levels and, in some cases, changes in urine consistent with myoglobinuria observed
                • Despite similar presentation to malignant hyperthermia, none of affected patients exhibited signs or symptoms of muscle rigidity or hypermetabolic state
                • Early and aggressive intervention to treat hyperkalemia and resistant arrhythmias recommended
                • Evaluation for latent neuromuscular disease recomended

                General anesthetics and sedation drugs in young children and pregnant women

                • Brain development
                  • Prolonged or repeated exposure may result in negative effects on fetal or young children’s brain development
                  • Caution with use during surgeries or procedures in children younger than 3 yr or in pregnant women during their third trimester
                  • Assess the risk:benefit ratio in these populations, especially for prolonged procedures (ie, >3 hr) or multiple procedures
                Previous
                Next:

                Pregnancy & Lactation

                Pregnancy

                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 live- birth index) during organogenesis

                Lactation

                Use caution

                Pregnancy Categories

                A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

                B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

                C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

                D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

                X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

                NA: Information not available.

                Previous
                Next:

                Pharmacology

                Mechanism of Action

                Volatile liquid inhalation anesthetic

                Pharmacokinetics

                Onset: Rapid (7-10 min)

                Duration: Short (depends on blood concentration)

                Minimum Alveolar Conc: 1.3%

                Metabolism: Liver (0.2%)

                Pharmacogenomics

                Increased incidence of malignant hyperthermia with use of volatile anesthetics or depolarizing neuromuscular blockers in patients with gene mutations in ryanodine receptor (RYR1) or calcium channel alpha (1S)- subunit gene (CACNA1S)

                Previous
                Next:

                Images

                BRAND FORM. UNIT PRICE PILL IMAGE
                isoflurane inhalation
                -
                99.9 % liquid
                isoflurane inhalation
                -
                99.9 % liquid

                Copyright © 2010 First DataBank, Inc.

                Previous
                Next:

                Patient Handout

                Patient Education
                isoflurane inhalation

                NO MONOGRAPH AVAILABLE AT THIS TIME

                USES: Consult your pharmacist.

                HOW TO USE: Consult your pharmacist.

                SIDE EFFECTS: Consult your pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

                PRECAUTIONS: Consult your pharmacist.

                DRUG INTERACTIONS: Consult your pharmacist.Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

                OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

                NOTES: No monograph available at this time.

                MISSED DOSE: Consult your pharmacist.

                STORAGE: Consult your pharmacist.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

                Information last revised July 2016. Copyright(c) 2021 First Databank, Inc.

                IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

                Previous
                Next:

                Formulary

                FormularyPatient Discounts

                Adding plans allows you to compare formulary status to other drugs in the same class.

                To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

                Adding plans allows you to:

                • View the formulary and any restrictions for each plan.
                • Manage and view all your plans together – even plans in different states.
                • Compare formulary status to other drugs in the same class.
                • Access your plan list on any device – mobile or desktop.

                The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

                Tier Description
                1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
                2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
                3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
                4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
                5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
                6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
                NC NOT COVERED – Drugs that are not covered by the plan.
                Code Definition
                PA Prior Authorization
                Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
                QL Quantity Limits
                Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
                ST Step Therapy
                Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
                OR Other Restrictions
                Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
                Additional Offers
                Email to Patient

                From:

                To:

                The recipient will receive more details and instructions to access this offer.

                By clicking send, you acknowledge that you have permission to email the recipient with this information.

                Email Forms to Patient

                From:

                To:

                The recipient will receive more details and instructions to access this offer.

                By clicking send, you acknowledge that you have permission to email the recipient with this information.

                Previous
                Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.