[Metamizol-caffeine elimination in females with increased serum aminotransferase activities treated with steroidal oral contraceptives].

The elimination of caffeine from the plasma and the excretion of the major metabolites of metamizol (AnalginR) in the urine was studied in 25 women on long-term oral steroid contraceptives. Both tests allowed to draw conclusions about metabolic liver function. A steroid-induced delay of the elimination of caffeine in clinically healthy women with/without serologic elevation of aminotransferase activities was demonstrated. --We regard this as the consequence of an inhibition of the cytochrome P-450-dependent poly-functional oxidases of the P-450MC type, which was produced by oral contraceptives. The differences in the elimination of metamizol were not significant.