Aspartate aminotransferase, alanine aminotransferase, and glutathione transferase in plasma during and after sedation by low-dose isoflurane or midazolam.

To assess the effect of prolonged administration of midazolam or isoflurane on hepatocellular integrity, we measured the concentrations of glutathione transferase (EC 2.5.1.18) B1 subunit and the activities of alanine aminotransferase (ALT; EC 2.6.1.2) and aspartate aminotransferase (AST; EC 2.6.1.1) in 40 patients who required long-term sedation with low-dose midazolam or isoflurane. Blood samples were collected before and 24 h after the start of the sedation and 0, 24, 72, 120, and 172 h after the last dose. ALT and AST activities did not change appreciably, but the glutathione transferase B1 concentration decreased significantly (P less than 0.03) at all times studied. The patients who received isoflurane and those who received midazolam showed no significant differences in any of the enzyme tests. We conclude that long-term sedation with midazolam or isoflurane is unlikely to affect hepatocellular integrity.