After the morphine extended-release tablets are resistant to the drug, you can consider replacing it with other drugs such as codeine and pethidine, which are strictly controlled drugs and addictive, and need to be used under the guidance of a doctor. Morphine is mainly used for analgesia in advanced cancer, and under normal circumstances, drug resistance and addiction can occur with continuous use. If resistance occurs, it is recommended to change drugs such as codeine, pethidine and methadone. Adverse reactions such as nausea, vomiting, drowsiness, vertigo respiratory depression, constipation, itching, etc. may occur with morphine, and if overdosed, acute toxicity, respiratory depression, increased intracranial pressure and other diseases may occur. Morphine is prohibited for infants, pregnant women, and lactating women. All of the above drugs belong to the national special management of narcotic drugs, must be used under the guidance of a doctor, not private random use.