Riha HM, et al. - Authors undertook this systematic review to critically evaluate evidence describing the off-label use of fresh frozen plasma (FFP), prothrombin complex concentrate (PCC), complement 1 esterase inhibitor (C1-INH), icatibant, and ecallantide for treatment of Angiotensin-converting enzyme inhibitor (ACEI)-induced angioedema. As per findings, each of these therapies resulted in decreased time to symptom resolution or a cessation in symptom progression. However, an additional study was required to assess clinically relevant implications, such as reduced intensive care unit length of stay or avoidance of mechanical ventilation, especially when taking cost into consideration. Limited evidence suggested FFP as beneficial for treatment of ACEI-induced angioedema without consistent dosing strategies. However, given its wide availability and low potential for adverse reactions, FFP therapy may be reasonable. Of the novel agents traditionally used for hereditary angioedema, the highest level of evidence was gained for icatibant and it seemed successful in limiting the progression of angioedema.