Isoflurane

DEA Class;  Rx

Common Brand Names; Forane

Hypersensitivity to isoflurane & halogenated agents

Genetic susceptibility to malignant hyperthermia

Patients in whom general anesthesia contraindicated

History of confirmed hepatitis due to a halogenated inhalational anesthetic or a history of unexplained moderate to severe hepatic dysfunction (eg, jaundice associated with fever and/or eosinophilia) after anesthesia with isoflurane or other halogenated inhalational anesthetics

• Nausea
• Vomiting
• Shivering
• 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)

Caution in coronary heart disease

May decrease renal and hepatic blood flow

Postoperative hepatic dysfunction and hepatitis reported

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

Therapy should only be administered in an adequately equipped anesthetizing environment by those who are familiar with the pharmacology of the drug and qualified by training and experience to manage the anesthetized patient

All patients receiving the drug should be continually monitored (eg, monitoring of the electrocardiogram, blood pressure, oxygen saturation, and end tidal CO2)

The drug 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

With the exception of neonates, isoflurane MAC decreases with increasing age

QTc prolongation, with rare instances of torsade de pointes, reported; monitor QT interval when administering the drug to susceptible patients

Regardless of the anesthetics employed, maintenance of normal hemodynamics is important to the avoidance of myocardial ischemia in patients with coronary artery disease

Isoflurane can cause dose-dependent coronary vasodilation and has been shown to divert blood from collateral-dependent myocardium to normally perfused areas in an animal model (“coronary steal”); monitor for signs of inadequate myocardial perfusion via hemodynamic monitors (eg, ECG, blood pressure) during administration; consider additional cardiac monitoring in patients with known coronary artery disease, as clinically necessary

There are no adequate and well-controlled studies in pregnant women; in animal reproduction studies

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