RESUMEN
Realgar-containing Niuhuang Jiedu tablet (NHJD) has been applied in clinic for more than 800 years. However, because realgar contains arsenic (As), it has aroused wide concerns and controversies both at home and abroad. Currently, there are two misunderstandings about realgar-containing Chinese patent medicines. First, some people exaggerated realgar's toxicity as that of arsenic. Second, they recommended to remove realgar from traditional Chinese medicine compounds. In this paper, the authors summarized the advance in studies on NHJD, and proposed different opinions: (1) It is inappropriate to take total As as the index in safety evaluation of NHJD. (2) The toxicity of NHJD is dependent on the dose and duration of administration. (3) Realgar is an active ingredient of NHJD, and shall be deeply studied. Classic realgar-containing traditional Chinese medicine prescriptions, such as Niuhuang Jiedu tablet, shall be evaluated with rigorous modern scientific basis, with the aim to guide rational and safe application.