13C-methacetin breath test reproducibility study reveals persistent CYP1A2 stimulation on repeat examinations

Figure 4 Corresponding curves of the momentary ¹³C recovery in breath air after peroral administration of 75 mg ¹³C-methacetin in 20 healthy volunteers if two examinations were taken at a median of 2 d apart (panel A) or if the examinations were separated by a median 18 d gap (panel B). Open symbols, the first administration, filled symbols, the second administration, the values shown are mean ± SE. See the text for the results of the statistical comparison of the matching D_max and AUC_0-60 values.