The effect of rifampicin on human mononuclear cell gene expression

The aim of the study was to elucidate the effects of pregnane receptor X (PXR) activation by rifampicin on the mononuclear cell gene expression in vivo. Twelve individuals (healthy volunteers, aged 19-38 years) were administered 600 mg rifampicin (Rimapen; Orion Corporation, Espoo, Finland) or placebo daily for a week with at least a 4-week washout period before the next treatment arm. At the end of each arm, blood samples were collected on the morning of the eighth day. The study had randomized, open, and placebo-controlled crossover design. This trial was registered at ClinicalTrials.gov as NCT00985270.