泽泻

纲目称其行水泻肾．仲景地黄丸用茯苓泽泻者．取其泻膀胱之邪气．古人用补药必兼泻邪．邪去则补药得力．后世不知此理．一意用补．故久服有偏胜之患．是泽泻但长于利水．未可专任．扁鹊云．多服病患眼．盖小便利．肾气虚．故昏目也．本草久服云云．扬之太过．用者审之．