Introduction
Hemorrhagic cystitis (HC) is a common complication following hematopoietic stem cell transplant (HCT) associated with viral infections and/or administration of high dose cyclophosphamide (CY).1,2 Preventative measures including hyperhydration and the acrolein-neutralizing agent mesna are useful in preventing HC but do not prevent all cases.3 Once HC occurs, the associated dysuria can be debilitating and difficult to treat.1 For this reason, multiple agents are used to treat severe dysuria. This poly-pharmacy approach may lead to drug related adverse effects and complicate the post-HCT recovery phase. We present a case of a girl who experienced HC secondary to CY, treated conservatively with hyperhydration, phenazopyridine, and oxybutynin, who suddenly developed acute hemolysis.