Table 1.

Induction ratios for 6β-hydroxycortisol : cortisol, 4β-hydroxycholesterol, 4β-hydroxycholesterol : cholesterol and quinine metabolic ratio (MR) in volunteers treated for 2 weeks with 20, 100 or 500 mg rifampicin day⁻¹ (mean ± SD, n = 8). Data on 4β-hydroxycholesterol and quinine metabolic ratio (MR) are from a previous publication 5

Rifampicin (mg day−1)	6β-OH-cortisol : cortisol	4β-OH-cholesterol	4β-OH-cholesterol : cholesterol	Quinine MR
20	1.77 ± 0.82	1.46 ± 0.24	1.53 ± 0.20	1.57 ± 0.33
100	3.92 ± 3.28	2.49 ± 0.66	2.40 ± 0.75	2.95 ± 1.10
500	4.46 ± 1.81	4.06 ± 0.85	3.76 ± 0.67	4.25 ± 2.07