Cancer pain is one of the most common symptoms of cancer patients. Cancer pain can cause strong excitation of the pain nerve, which will affect the metabolism and endocrine function of the body, leading to the decrease of immunity, depression and demoralization, which is “worse than death”. If the pain is not eliminated in time, it is also very detrimental to the treatment of cancer itself. Therefore, about 70% of patients with advanced cancer must rely on opioids for pain management. However, some patients think that painkillers are equivalent to “opium” and will be addicted to them, so they try to cover up the pain symptoms; some family members think that pain is a concomitant symptom of cancer and pain is inevitable. In fact, many studies at home and abroad have shown that the incidence of addiction to opioid drugs for chronic cancer pain patients is extremely rare. The main opioids used for the treatment of moderate to severe pain include tramadol, codeine, morphine sulfate controlled-release tablets (Methocarbamol), oxycodone controlled-release tablets (OxyContin) and fentanyl transdermal patches (Doregis). There are also some adverse effects associated with long-term opioid use, such as constipation, nausea and vomiting, drowsiness and excessive sedation, difficulty urinating, and respiratory depression. These adverse reactions should be taken seriously by patients and their families. Constipation: The most common adverse reaction, which may accompany the whole process of taking the drug and will not gradually improve or disappear with the prolongation of taking the drug. Therefore, family members should be concerned about the patient’s bowel movements at the beginning of the drug administration. If the patient is constipated or has dry stools, he or she should take opioids together with a laxative. Commonly used laxatives include marijuana pills, rhubarb soda tablets, cistus laxative capsules, senna leaves, aloe capsules, etc. In severe cases, the following can be considered: phenolphthalein tablets, magnesium sulfate, lactulose, paraffin oil, and enemas with open cork, etc. At the same time, family members should encourage patients to drink more water, eat more foods high in dietary fiber or take one to two tablespoons of honey every morning to help relieve constipation. Nausea and vomiting: A small number of patients may experience nausea and vomiting at the beginning of taking the drug. However, after a week or so, the body can develop tolerance to opioids and symptoms can gradually decrease until they disappear. To prevent nausea and vomiting, you can take prophylactic anti-vomiting medication, such as Gastrodia tablets, orally along with the first pill. Family members can also boil ginger black tea water to stop vomiting, or use ginger, Chen Pi, Mu Xiang, half asia and other Chinese herbal decoction to regulate, and can also use acupuncture foot three miles to stop vomiting. If there is recurrent severe nausea and vomiting and vomiting when eating, ask for help from the doctor to give central antiemetics or change to other types of opioids for treatment. Drowsiness and excessive sedation: Rarely present. Drowsiness mostly disappears as the medication continues. Some of the causes may be due to severe cancer pain affecting the patient’s sleep before treatment and greatly improved sleep after effective pain management, with significantly longer sleep duration. Other patients may be due to the fact that the initial dose of pain medication given is greater than the actual amount needed. A small number of patients may also be related to tumor brain metastasis, combined with the use of sleeping drugs. If the dose of opioid is too high, the dose should be reduced and the sleeping drugs should be stopped. Tea, coffee and other beverages can be given to drink, and ginseng and American ginseng can also have certain excitatory effects. Difficulty in urination: A small number of patients have difficulty in urination after the first dose of opioids. The sound of running water can be tried at the bedside to induce urination or warm towels on the perineum to promote urination. In severe cases, a doctor must be consulted for catheterization. If symptoms of dyspareunia recur, consider switching to opioids such as fentanyl transdermal patches and oxycodone hydrochloride, which have less effect on urinary retention. Respiratory depression: A more serious side effect of opioids, extremely rare. Generally, under the guidance of professional doctors, starting with lower doses of opioids and gradually increasing the dose, respiratory depression rarely occurs. In patients of advanced age, advanced tumor, extreme failure, and combined renal insufficiency, close observation should be made at the beginning of treatment or after adjustment of medication to exclude respiratory depression due to terminal disease and cardiopulmonary failure. In case of respiratory depression, a physician should be called immediately for resuscitation, establishment of respiratory access, and treatment with naloxone, an antagonist of opioids. In conclusion, through standardized treatment, the toxic side effects of opioids can be minimized, so that patients can achieve “pain-free sleep, pain-free rest, and pain-free activity” and their quality of life can be greatly improved.