Nitrous oxide is not metabolized (Table 1).

Isoflurane (Fig 1) and sevoflurane (Fig 2) are both halogenated ethers and are metabolized in the liver by CYP2E1, one of the cytochrome P450 family of enzymes.

Sevoflurane is metabolized to a greater extent than isoflurane. Given its structure, it is no surprise that its metabolism produces significant amounts of fluoride ions, which are known to cause renal impairment. Despite this, sevoflurane does not appear to impair renal function, even after prolonged exposure.