p450 - publications
A comparison of 4β-hydroxycholesterol/cholesterol and 6β-hydroxycortisol/cortisol as markers of CYP3A4 induction.
Br J Clin Pharmacol. 2012 Nov 1;
Authors: Mårde Arrhén Y, Nylén H, Lövgren-Sandblom A, Kanebratt KP, Wide K, Diczfalusy U
AIM: To compare plasma 4β-hydroxycholesterol/cholesterol to urinary 6β-hydroxycortisol/cortisol as markers of CYP3A4 activity before and after treatment with rifampicin for two weeks. METHOD: 6β-Hydroxycortisol and cortisol were determined by LC-MS/MS and 4β-hydroxycholesterol was determined by GC-MS in 3 groups of healthy volunteers. RESULTS: Induction ratios for 6β-hydroxycortisol/cortisol were 1.8, 3.9 and 4.5 for 20 mg/day, 100 mg/day or 500 mg/day of rifampicin, respectively. The corresponding ratios for 4β-hydroxycholesterol /cholesterol were 1.5, 2.4 and 3.8. CONCLUSIONS: Plasma 4β-hydroxycholesterol/cholesterol gave similar induction ratios as urinary 6β-hydroxycortisol/cortisol.
PMID: 23116409 [PubMed - as supplied by publisher]