DEXAMETHASONE ON CYTOCHROME P450 3A4 ACTIVITY

本研究将测试以下假设：口服地塞米松（8 毫克，口服，每日两次，持续 5 天）会改变健康志愿者的肝脏和/或肠道细胞色素 P450 3A4 (CYP3A4) 活性。 CYP3A4 途径代谢大约一半的口服药物。 地塞米松作为化疗方案的一部分给予大量癌症患者，以减少化疗引起的呕吐或其他化疗相关副作用的可能性。 人肝细胞和少量临床数据表明CYP3A4活性是由地塞米松诱导的。 CYP3A4 活性的改变可以影响通过该途径代谢的抗肿瘤药物的生物利用度和清除率，因此可能改变其全身暴露、功效和/或毒性。

This study will test the hypotheses that oral dexamethasone (8 mg, PO BID for 5 days) alters hepatic and/or intestinal cytochrome P450 3A4 (CYP3A4) activity in healthy volunteers. The CYP3A4 pathway metabolizes approximately half of orally administered medications. Dexamethasone is administered to a large number of cancer patients as part of their chemotherapy regimen, to decrease the likelihood of chemotherapy induced emesis or other chemotherapy associated side effects. Human heptocyte and a small amount of clinical data demonstrate CYP3A4 activity is induced by dexamethasone. Alterations in CYP3A4 activity can affect the bioavailability and clearance of antineoplastics metabolized by this pathway, therefore potentially altering their systemic exposure, efficacy and/or toxicity.