ABSTRACT
<p><b>OBJECTIVE</b>To investigate the laws of eighteen incompatible medicaments of the chest pain prescriptions based on association rules mining.</p><p><b>METHOD</b>The database of chest pain prescription was established and then the chest pain prescriptions composed of eighteen incompatible medicaments were screened. The dynasty, couplet medicines, the property and flavor of drugs and preparation form were analyzed with the frequent item sets and corresponding analysis methods.</p><p><b>RESULT</b>Eight hundred and fifty chest pain prescriptions were collected, and 88 of them contained eighteen incompatible medicaments, taking 10.3% of all; the applications of ancient and modern chest pain prescriptions containing eighteen incompatible medicaments are significant difference (P < 0.05). Ancient formulas, mainly focus on the eastern jin dynasty and tang dynasty, are more often used than the modern formulas. The most common anti-drugs is on the Fuzi-Pinellia, Chuanwu-Pinellia; the property and flavor of drugs is bitter cold most closely; the decoction of the formulas is mostly used.</p><p><b>CONCLUSION</b>Eighteen incompatible medicaments account for about ten percent of the chest pain prescription, not an uncommon side. There are certain rules for application of anti-drug compatibility to treat chest pain.</p>