Class I pain relief is indicated for general pain. Use non-narcotic analgesics plus or minus adjuvants (non-steroids). That is: aspirin 200~1000 mg, q4h, after meal, enteric dissolved aspirin or with antacids is required. Class II pain relief is indicated for moderate persistent pain or worsening pain. Use weak narcotics plus or minus non-narcotic analgesics plus or minus adjuvants. I.e., codeine 30 mg plus aspirin 650 mg (approximately equal to codeine 30 mg), q4h. Class III analgesia is indicated for intense persistent pain. Use strong narcotics plus non-narcotic analgesics plus adjuvants. That is, morphine 10 mg plus aspirin until the pain subsides. Route of morphine administration: oral, sublingual or anal suppository. The World Health Organization has set the strategic goal of “relieving pain for most cancer patients by the year 2000”. In 1984, WHO invited 28 medical, pharmacological and nursing experts to discuss and formulate a “three-tier pain relief” program, the content of which is briefly described as follows: adjuvants refer to sedative tranquilizers, dormant, Valium, steroids, prednisone, dexamethasone, etc. The adjuvant should be chosen according to the needs of the disease. According to the World Health Organization, there are about 7 million new cancer patients worldwide every year, 30 to 50% of which are accompanied by different degrees of pain. In China, a recent survey showed that 51.1% of patients with various stages of cancer in general and specialized hospitals were accompanied by different degrees of pain. After discussion, it was agreed that the application of existing and limited analgesic drugs could relieve the pain of most cancer patients. In April 1991, the Ministry of Health issued a notice on “three-stage pain relief ladder treatment for cancer patients” with the document No. 12 of Health Drug Development (91). The purpose is to ensure the proper use of painkillers in medical treatment to relieve the pain of cancer patients; however, the management should be strengthened to prevent abuse. In general, cancer pain should be diagnosed first and then treated by appropriate methods. At present, pain of cancer patients is usually divided into four categories internationally: (1) pain directly caused by cancer; (2) pain related to cancer; (3) pain related to cancer treatment; (4) pain not related to cancer such as gout and arthritis that patients had before. From our recent survey, (1)(2) causes accounted for 78.6% and 6.0%, respectively, (3) accounted for 8.2%, while (4) accounted for 7.2%, and 6.7% of patients had pain caused by more than two causes. It is self-evident that for the pain caused by (1)(2), anti-tumor treatment can relieve the pain to a certain extent, so the treatment principle should be anti-tumor plus pain relief; while for the pain caused by (3)(4), pain relief and other related adjuvant treatments are needed. The so-called three-step approach of cancer pain treatment is to select the appropriate analgesic according to the degree and cause of pain after a correct assessment of the nature and cause of cancer pain, i.e., for patients with mild pain, analgesics of antipyretic type should be mainly used; for moderate pain, weak opioids should be used; for severe pain, strong opioids should be used (Table 1). Note that the use of analgesics should be increased step by step from weak to strong. The main principles of drug treatment for cancer pain (a) Oral drug administration Oral drug administration route should be chosen to avoid traumatic drug administration route as much as possible, so as to facilitate long-term drug use by patients. Especially for strong opioids (such as morphine tablets and syrups), proper oral administration rarely produces mental dependence (addiction) or physical dependence (<1%). This is because what cancer patients require is analgesic effect rather than mental enjoyment. Also, oral morphine does not meet the needs and effects of the addict. (b) Timely administration Pain medication should be given regularly "on time" (once every 3-6 hours) rather than "on demand" - only when the pain is present. (c) Stepwise dosing Mild pain Non-opioid analgesics should be given as adjuvants Moderate pain Weak opioids ± non-opioid analgesics ± adjuvants Severe pain Strong opioids ± non-opioid analgesics ± adjuvants (d) Dosing should be individualized, i.e., attention should be paid to the actual efficacy of the specific patient. The dosage of pain medication should be small to large according to the patient's needs until the pain disappears. The dosage should not be too restrictive, resulting in underdosing. Grading of pain and evaluation of efficacy (a) Grading Grade 0: no pain Grade 1 (mild pain); painful but still tolerable, and can live a normal life, sleep is not disturbed. Grade 2 (moderate pain); pain is obvious, unbearable, requiring analgesic drugs, sleep is disturbed. Grade 3 (severe pain); pain is severe and unbearable, requiring analgesic drugs, sleep is seriously disturbed, and may be accompanied by the manifestation of plant nerve dysfunction or passive body position. (B) Evaluation of efficacy Since pain is a subjective phenomenon, there are two methods commonly used to evaluate the efficacy after drug administration: (1) the change in the degree of pain complained of, (2) the method of drawing a line, that is, the pain is divided into 0 degrees to 10 degrees (no pain, mild pain to extreme pain), so that the patient can draw a line to indicate the change in the degree of pain after taking the drug. This method has been applied in many countries, which not only can clearly express the degree of pain of patients, but also can reflect the dynamic changes after drug administration. The efficacy can be classified according to the above records: Complete remission (CR): complete pain-free after treatment. Partial remission (PR): pain is significantly reduced compared with that before drug administration, sleep is basically undisturbed, and normal life can be lived. Mild remission (MR): the pain is less than before the drug was administered, but still feels significant pain, sleep is still disturbed. No effect (NP): no reduction compared with before treatment.