4β-Hydroxycholesterol level significantly correlates with steady-state serum concentration of the CYP3A4 substrate quetiapine in psychiatric patients.

The present study shows that 4βOHC level is significantly correlated with steady-state concentration of quetiapine. This supports the potential usefulness of 4βOHC as a phenotype biomarker for individualized dosing of quetiapine and other drugs where systemic exposure is mainly determined by CYP3A4 metabolism.