Rifampicin is a potent inducer of the cytochrome p450 oxidative system, responsible for the metabolism of Prednisolone. Previous studies have shown a reduction in the half life of cortisol in patients treated with simultaneous Rifampicin. In these studies, the half-life of cortisol returned to normal when Rifampicin was ceased. There are minimal studies available describing the effect after cessation of Rifampicin. We present a patient with Addisonian crisis 13 days after cessation of Rifampicin likely due to sustained induction of cytochrome p450 and therefore recommend close monitoring up to 2 weeks after cessation of Rifampicin in patients taking daily Prednisolone.