The principle of “three-step therapy” Clinical practice at home and abroad has proved that the simple, effective, recognized and reasonable “three-step therapy” designed by the World Health Organization can effectively relieve the pain of 90% of cancer patients, and relieve the pain of more than 75% of advanced cancer patients. More than 75% of advanced cancer patients can have their pain relieved and improve their quality of life. The principles of “three-step therapy” are: oral administration of drugs, timely administration of drugs, administration of drugs according to the ladder, and individualization of drug dosage. The principle of oral administration: oral administration does not need the help of others, it is more convenient, safe and economical. If the patient has dysphagia, severe vomiting or gastrointestinal obstruction, fentanyl transdermal patch or other rectal suppositories can be used, and only if necessary, choose the infusion pump for continuous subcutaneous infusion of drugs. ② ladder principle: the standardized pain management principle of the three-step ladder should be strictly implemented like the routine of radiotherapy, chemotherapy and surgery. ③ On-time principle: pain medication should be given regularly at planned intervals rather than waiting for the patient to request it. The next dose should be given before the previous dose wears off, so as to ensure continuous pain relief. Those with sudden severe pain can be given painkillers temporarily on demand. ④ Individualization principle: The dosage of analgesics varies from person to person, and the effective pain-relieving dose varies greatly from patient to patient. For each individual, the dose that meets the individual’s specific needs should be selected. The appropriate dose of analgesics should ensure that the analgesic effect can be maintained for more than 4 hours without obvious adverse effects. The dose of strong opioids can be increased without limitation. ⑤ Principle of detail: The physician must examine in detail and identify whether the pain is caused by the tumor itself, or by other treatments, or by comorbidities, or by other pain unrelated to the cancer. In addition, it is important to identify localized and involved pain, whether the pain is from peripheral nerve or plexus and spinal cord involvement, and what aggravates the pain and what relieves it. This is the basis for choosing reasonable pain relief measures. Specific contents of the three-step pain relief treatment for cancer ① The first step – non-opioid drugs: patients with mild cancer pain that is generally tolerable and able to live a normal life and sleep basically undisturbed should use non-opioid painkillers . The most commonly used are non-steroidal anti-inflammatory drugs (NSDIDs).NSAIDs include: aspirin, diclofenac, nimesulide, celecoxib and so on. They are effective for pain arising from metastatic cancer pain in the bone, mechanical pulling of the periosteum by the tumor, soft tissue compression such as muscle or subcutaneous, or pleural/peritoneal compression. Adverse reactions should be familiarized at the time of application, including platelet dysfunction, peptic ulcer, and renal damage. The occurrence of adverse effects is closely related to the dose, so the adverse effects, capping effects, and restrictive dosage of NSDIDs should be fully considered in patients requiring long-term pain management. Do not blindly increase the dosage, if the pain relief is not satisfactory, then promptly enter the second stage. ② The second ladder – weak opioids: when non-opioid drugs can not satisfactorily relieve pain, sleep has been disturbed, loss of appetite when the application of weak opioid painkillers. Such drugs include codeine and oxycodone. The principle of gradual transition to the second ladder should be adopted, i.e., weak opioid analgesics should be given gradually along with NSDIDs. ③ The third ladder – strong opioids: strong opioids are used for moderate to severe cancer pain with poor response to non-opioids and weak opioids. Most of the patients are satisfied with the pain relief after using this kind of drugs, but it is easy to produce drug dependence and drug resistance, and the effect of repeated use of the drugs gradually decreases, and it is necessary to increase the dosage continuously to maintain the pain relief effect. Strong opioid painkillers have great individual differences in efficacy, usually starting from a small dose, according to clinical experience to increase to the appropriate dose. Opioids do not have a ceiling on their analgesic effect, which increases with increasing dose. Immediate-release morphine dosage: 5 to 200mg orally every 4 hours. Generally start with 5mg, individually 10mg or more. If the patient has good pain relief and is drowsy after the first oral dose, the dosage can be reduced for the second dose, and conversely, the dose can be increased for the second dose or the interval between doses can be shortened. Morphine controlled-release tablets can be taken orally every 12 hours. Precautions for the clinical application of strong opioids: ① Timely application, full dose, and often adjust the dose according to the condition; ② Increase the single dose of the drug when the pain worsens, but do not increase the number of times the drug is given; ③ Those who are treated with immediate-release morphine can double the dose before bedtime to prevent waking up from the pain; ④ Controlled-release tablets should not be crushed and applied; ⑤ The intensity of the pain and the process of dosage adjustment should be recorded; and ⑥ Attention should be given to the prevention and treatment of the adverse effects of the drug. In the treatment of cancer pain, the patient’s complaints should be believed, persistent pain must be given a sufficient amount of painkillers, and at the same time, scientific assessment of pain is the guarantee of pain control. The safety and reliability of the three-step pain relief method has been verified by the popularization and application of the three-step pain relief method around the world. After years of research and practice, the new concept of cancer pain treatment nowadays believes that opioids are the cornerstone of cancer pain treatment and the most important part of analgesic drugs in chronic cancer pain treatment, and the consumption of morphine in a country is often used as a mark to judge the level of pain control in this country in the international arena. And opioidophobia is the main reason for inadequate treatment of cancer pain.