METABOLISM AND TOXICITY OF INHALATION ANAESTHETICS
It was originally thought that anaesthetics were too unreactive to be metabolised in the body, but in fact the metabolism of halogenated anaesthetics can be considerable, and the resulting metabolites contribute appreciably to certain toxic effects. Chloroform (now obsolete) produces hepatotoxicity associated with free radical formation in liver cells. Methoxyflurane, a halogenated ether, is now rarely used, because about 50% is metabolised, generating fluoride and oxalate, which cause renal toxicity. Euflurane also generates fluoride, but at muchlower (non-toxic) levels. Halothane is the only volatile anaesthetic in current use which undergoes substantial metabolism, about 30% being converted into bromide trifluoroacetic acid and other metabolites which may be responsible for the rare occurance of liver toxicity.....
INDIVIDUAL INHALATION ANAESTHETICS
The inhalation anaesthetics currently used in developed western countries are: Halothane, Nitrous oxide, Enflurane and Isoflurane. Ether, used for many years but now obsolete, is still used in some parts of the world...... Methoxyflurane is rarely used because of it's renal toxicity. Desflurane and Sevoflurane have been introduced recently