In the case of Trasylol, which works by blocking enzymes that dissolve blood clots, the agency assumed that any drug that reduced excessive bleeding during heart surgery would benefit patients.

• 特雷西洛通过抑制溶血凝块酶的活性减少出血，FDA仅据此就认为，象特雷西洛这样的药物，只要能减少过多出血，对实施心脏外科手术的病人都是有利的。