SLCO1B1 and toxicity: For example, inhibition of human bile salt export pump (BSEP) may correlate with the increased risk of cholestatic liver toxicity caused by the inhibitor drug.18,47 Both dicloxacillin and flucloxacillin inhibit human BSEP.18,47 Recently, inhibition of OATP1B1 was reported to be a risk factor for drug-induced cholestasis.48 Based on our results, dicloxacillin and flucloxacillin inhibit and are transported by OATP1B1.