Isoflurane

The Basics

What is Isoflurane?

Used to start or maintain anesthesia, though other medications are often used to start anesthesia.

Brand names for Isoflurane

Forane

How Isoflurane is classified

Anesthetics – Inhalation

Isoflurane During Pregnancy

Isoflurane pregnancy category

Category CNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Isoflurane while pregnant

N/A

Taking Isoflurane While Breastfeeding

What are recommendations for lactation if you're taking Isoflurane?

There is no published experience with isoflurane during breastfeeding. Because the serum half-life of isoflurane in the mother is short and the drug is not expected to be absorbed by the infant, no waiting period or discarding of milk is required.[1] Breastfeeding can be resumed as soon as the mother has recovered sufficiently from general anesthesia to nurse. When a combination of anesthetic agents is used for a procedure, follow the recommendations for the most problematic medication used during the procedure. In one study, breastfeeding before general anesthesia induction reduced requirements of sevoflurane and propofol compared to those of nursing mothers whose breastfeeding was withheld or nonnursing women.[2] It is possible that requirements for other anesthetic agents would be affected similarly.

Maternal / infant drug levels

There is no published experience with isoflurane during breastfeeding. Because the serum half-life of isoflurane in the mother is short and the drug is not expected to be absorbed by the infant, no waiting period or discarding of milk is required.[1] Breastfeeding can be resumed as soon as the mother has recovered sufficiently from general anesthesia to nurse. When a combination of anesthetic agents is used for a procedure, follow the recommendations for the most problematic medication used during the procedure. In one study, breastfeeding before general anesthesia induction reduced requirements of sevoflurane and propofol compared to those of nursing mothers whose breastfeeding was withheld or nonnursing women.[2] It is possible that requirements for other anesthetic agents would be affected similarly.

Possible effects of Isoflurane on milk supply

A randomized, but nonblinded, study in women undergoing cesarean section compared epidural anesthesia with bupivacaine to general anesthesia with intravenous thiopental 4 mg/kg and succinylcholine 1.5 mg/kg for induction followed by nitrous oxide and isoflurane. The time to the first breastfeed was significantly shorter (107 vs 228 minutes) with the epidural anesthesia than with general anesthesia. This difference was probably caused by the anesthesia’s effects on the infant, because the Apgar and neurologic and adaptive scores were significantly lower in the general anesthesia group of infants.[3]

Possible alternatives to Isoflurane

Desflurane, Enflurane, Sevoflurane.