Morphine is used in the treatment of severe cancer pain, etc. It is relatively easy to develop drug resistance after 3-5 days of continuous use of the drug. According to the WHO’s three-step program for the treatment of cancer pain, morphine is the “gold standard” for the treatment of severe cancer pain. According to some studies, after 3~5 days of continuous use of morphine, the time of pain relief will become shorter and shorter with the same amount of morphine, and it is easy to develop drug resistance. Morphine is mainly used for the treatment of severe cancer pain, and common adverse reactions include nausea, vomiting, respiratory depression, constipation, difficulty in urination, and biliary colic, etc. It is recommended to consult the doctor in time for the occurrence of the above symptoms. Some studies have pointed out that alternating Lovenox with morphine can effectively reduce the drug resistance of morphine in cancer pain patients, prolong the effective period and reduce the incidence of adverse reactions. It is contraindicated in cases of drug hypersensitivity, respiratory depression, presence of craniocerebral injury, asthma, obstructive pulmonary disease, pulmonary heart disease, hypothyroidism, hypocorticism, prostatic hypertrophy, dysuria, shock, toxic diarrhea, and intestinal obstruction. It should be noted that the drug is a strictly controlled spermatic drugs, absolutely prohibit unauthorized possession and unauthorized use, the use of the drug needs to be under the guidance of the clinician medication.