 In Period 2, multiple oral doses of rifampin will be administered once daily QD for 10 consecutive days with a single oral dose of deflazacort coadministered on Day 10 Treatment B. Pharmacokinetic sampling for 21-desacetyl-DFZ and, if data permit, deflazacort will be taken for 24 hours following deflazacort dosing on Day 10. Morning urine collection will be used to measure 6β-hydroxycortisol and free cortisol concentrations on Days 1, 4, 8, and 10 to evaluate the level of cytochrome P450 CYP enzyme induction. 