Suárez E, Aguilera L, Calvo R, Rodríguez-Sasiaín J M, Martínez-Jorda R
Department of Pharmacology, Basque Country University, Leioa, Spain.
Methods Find Exp Clin Pharmacol. 1991 Dec;13(10):693-6.
The in vitro effect of the halothane metabolite, trifluoroacetic acid, on the protein binding of three different benzodiazepines (diazepam, lorazepam and midazolam) has been investigated. Furthermore, protein binding of these drugs was studied in serum from patients under the effect of halothane anesthesia (1-2.5%; 2.5 h). Trifluoroacetic acid, 4 mmol/l, displaced diazepam and midazolam from serum and produced a marked increase in the free percentage, but did not influence lorazepam binding. Moreover, 48 h after the end of halothane anesthesia, there were changes in protein binding of diazepam (3.9 +/- 0.3% at 48 h vs. 3.3 +/- 0.3% before halothane anesthesia; p less than 0.05). It can be concluded that halothane anesthesia (1-2.5%; 2.5 h) may temporarily potentiate the pharmacological effect of diazepam in the postoperative period following anesthetic procedures.
