Biotransformation of Halothane in Humans:

The metabolic breakdown of halothane was quantitatively determined in two patients. Trifluoroacetic acid and bromide were found as metabolites in the urine. Both metabolites have a protracted excretion rate. Since the biological half-life of trifluoroacetic acid is unknown, one can calculate only the least amount of halothane that had been metabolized on the basis of the excreted trifluoroacetic acid: 12% in both patients. On the basis of the excreted urinary bromide, 20% and 17%, respectively, of the halothane taken up by the body was calculated to be metabolized, if one assumes a biological half-life of 12 days for bromide.