在使用药物治疗和预防疾病时，当达到预期目的后，根据病情的不同，有的应及时停药，有的往往要延长用药时间，避免病情反复或“反跳”。合理停药，是临床治疗学的重要环节。1及时停药可防止或降低药源性疾病的发生广谱抗菌素如长期使用或长期间断使用可引起二重感染，特别是老 In the use of drug treatment and prevention of disease, when the desired purpose, according to the different conditions, some should be promptly discontinued, and some often want to extend the medication time to avoid repeated or “rebound.” Reasonable withdrawal, is an important part of clinical treatment. A timely withdrawal can prevent or reduce the incidence of drug-induced diseases Broad-spectrum antibiotics such as long-term use or long-term intermittent use can cause double infection, especially the old