At present, the application of Chinese and Western medicines in combination is becoming more and more common, and there is still a lack of authoritative information on the contraindications of combining Chinese and Western medicines. Some people believe that the effect of Chinese medicine is slow and long lasting, while the effect of Western medicine is rapid and short lasting, so if Chinese and Western medicines are used at the same time, the effectiveness will definitely be greater. Although this idea has some truth, it is not entirely correct. Because the vast majority of Chinese and Western drugs can be taken at the same time, but there are a small number of drugs can not be taken at the same time, often at the same time will reduce the efficacy or side effects. The Chinese medicine that contains a lot of tannins should not be combined with vitamin B1. For example, the ground elm, child tea, five times the seeds, tiger scepter, boxelder, Lao Guan Cao, rhubarb, etc.. This kind of Chinese medicine can be permanently combined with vitamin B1 in the body, and make it excreted from the body, reducing the efficacy of the drug; also should not be combined with enzyme preparations, such as pepsin combination, multi-enzyme tablets, etc., they can interact with tannin, resulting in precipitation, reducing the efficacy of the drug; also should not be combined with protein drugs, so as not to generate tannin, thus affecting the efficacy. Chinese medicine containing a large number of flavonoids should not be taken with aluminum hydroxide, magnesium trisilicate, calcium carbonate and other drugs containing aluminum, magnesium and calcium, such as Scutellaria baicalensis, Sophora japonica, Coriander, Lonicera japonica, Chen Pi, Spirulina, etc. These flavonoids and metal ions can generate metal complexes, which can change the original nature and effect of the drug and lose its efficacy. Chinese medicines containing organic acids should not be combined with sulfonamides, such as hawthorn, schisandra and umeboshi. This is because organic acids can counteract the alkalizing effect of baking soda on urine and increase the toxicity of sulfonamides on the kidneys. This type of Chinese medicine should also not be combined with alkaline western drugs such as sodium bicarbonate and gastric soothing, because acid-base neutralization can cause the drug to lose its therapeutic effect. Ephedra, licorice and antler should not be taken together with monoamine oxidase inhibitors, such as eugenol, isoniazid, methylbenzylhydrazine and phenelzine, because these western drugs can inhibit the activity of monoamine oxidase, so that monoamine neurotransmitters such as norepinephrine and dopamine accumulate in nerve endings, and ephedrine in ephedra can promote the release of these neurotransmitters in large quantities, thus causing dizziness, headache, nausea, vomiting, diarrhea, This can cause dizziness, headache, nausea, vomiting, diarrhea, dyspnea, cardiac arrhythmia, and movement disorders. Diabetic patients should not combine with licorice and deer antler when taking oral hypoglycemic drugs such as benzosulfonylurea and hypoglycemia. Glycyrrhetinic acid hydrolysate in licorice has an adrenal glucocorticoid-like structure, and the components of deer antler also have a glucocorticoid-like structure, and glucocorticoids can cause amino acids and proteins to be transferred from skeletal muscle to the liver, and increase the production of glucose and glycogen due to the action of enzymes, so these herbal medicines can produce pharmacological antagonism with hypoglycemic drugs and reduce the effect of hypoglycemic drugs. Vitamin C, niacin tablets and glutamate should not be combined with Chinese medicines such as ginseng, scutellaria, gentian, and farinaceae, because the active ingredients of Chinese medicines are decomposed and reduce the efficacy after taking them together. The Chinese medicine Baohe Wan, Liuwei Dihuang Wan and Gastric Qi Wan should not be taken together with the western medicine Aluminum Hydroxide Gel, Aminophylline, Sodium Bicarbonate and Gastric Shu Ping. Because the first three Chinese medicines contain acidic drugs, while the last four western medicines are alkaline drugs, such as the simultaneous consumption of acid-base neutralization, so that both Chinese and Western medicines lose their therapeutic effect. Therefore, we should consult with the doctor when using medicines to treat illnesses, especially when taking Chinese and Western medicines at the same time, so as to avoid adverse reactions, resulting in additional illnesses. The doctor in the combination of Chinese and Western medicines, but also do not blindly combined, rashly engaged in, must be clear in the Chinese and Western medicine, under the premise of Chinese and Western theory as a guide, and to obtain the best combination of Chinese and Western medicines combined effect.