Home/Medicines/Isoflurane
All medicines

Isoflurane

Prescription
Inhalant general anesthetic
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
4 available
Interactions
2 documented
Formulations
1

Mechanism of action

Produces general anesthesia by enhancing inhibitory GABA-A receptor activity and inhibiting excitatory NMDA receptors in the CNS; provides dose-dependent CNS depression with minimal metabolism (<0.2%)

At a glance

Class
Inhalant general anesthetic
Schedule
Prescription
Storage
Below 25°C, tightly sealed, no preservative needed; use calibrated vaporizer

Dosing

🐕

Dog

General anesthesia induction and maintenance
Dose
1.28–2.5 % MAC
Route
inhalation
Frequency
Continuous during procedure
Max dose
5 % for induction/dose; 0 % for induction/day
Duration: Duration of surgical procedure
🐈

Cat

General anesthesia induction and maintenance
Dose
1.63–2.5 % MAC
Route
inhalation
Frequency
Continuous during procedure
Max dose
5 % for induction/dose; 0 % for induction/day
Duration: Duration of surgical procedure
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

🧴

Volatile liquid — 1

Strength
100%
Available in India

Storage

Below 25°C, tightly sealed, no preservative needed; use calibrated vaporizer

Safety

Absolute contraindications — do not use

  • Known susceptibility to malignant hyperthermia
    Sighthounds may have prolonged recovery
    Greyhound (sensitivity)

Use with caution

  • Severe hypovolemia
    May cause severe hypotension

Adverse effects

Common
Dose-dependent hypotension
Respiratory depression
Hypothermia
Serious
Malignant hyperthermia
Cardiac arrest (overdose)
Hepatotoxicity (very rare)

Monitoring parameters

SpO2ETCO2Heart rate and rhythm (ECG)Blood pressureBody temperatureAnesthetic depth
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Interactions

Moderate — 2

Fentanyl
moderate
Fentanyl CRI reduces isoflurane MAC by 40-60% (MAC-sparing effect), allowing lower vaporizer settings and less cardiovascular depression from inhalant.
Management: Intended beneficial interaction. Reduce vaporizer setting and monitor depth. Standard balanced anesthesia technique.
Dexmedetomidine
moderate
Dexmedetomidine premedication reduces isoflurane MAC by 50-90%. Profound MAC reduction means very low vaporizer settings needed.
Management: Reduce isoflurane significantly when dexmedetomidine is on board. Monitor depth closely — over-anesthesia and hypotension risk.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Brands

International

Forane
Baxter
IsoFlo
Zoetis

India

Aerrane
Baxter India
Isoflurane
Piramal

FAQs

Frequently asked questions

›What is Isoflurane?
Isoflurane is a inhalant general anesthetic used in pets. Produces general anesthesia by enhancing inhibitory GABA-A receptor activity and inhibiting excitatory NMDA receptors in the CNS; provides dose-dependent CNS depression with minimal metabolism (<0.2%)
›What is Isoflurane used for in pets?
Isoflurane is used in veterinary medicine for: General anesthesia induction and maintenance.
›What is the Isoflurane dose for dogs?
For dogs, Isoflurane is typically dosed as follows — General anesthesia induction and maintenance: 1.28–2.5 % MAC inhalation Continuous during procedure. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Isoflurane dose for cats?
For cats, Isoflurane is typically dosed as follows — General anesthesia induction and maintenance: 1.63–2.5 % MAC inhalation Continuous during procedure. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What are the side effects of Isoflurane?
Common: Dose-dependent hypotension, Respiratory depression, Hypothermia. Serious (call your vet immediately): Malignant hyperthermia, Cardiac arrest (overdose), Hepatotoxicity (very rare).
›Does Isoflurane need a prescription?
Yes. Isoflurane is a prescription medication and should only be administered under veterinary supervision.
›When should Isoflurane not be used?
Do not use Isoflurane if: Known susceptibility to malignant hyperthermia.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

References

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

  • Plumb's Veterinary Drug Handbook
  • Withrow & MacEwen's Small Animal Clinical Oncology
  • Merck Veterinary Manual
  • NRC Nutrient Requirements of Dogs and Cats
  • Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

  • ASPCA Animal Poison Control Center Guidelines
  • AAHA Diabetes Management Guidelines
  • ASPCA Poison Control Guidelines
  • RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

  • EPIC Study (J Vet Intern Med 2016)
  • JVIM FAT CAT Study

Regulatory & approvals — 1

  • CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

  • Washington State University VCPL MDR1 Database
Need help? 💬
Chat with us on WhatsApp