This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy: General Principles, Subject name: Pharmacology
[{'content': 'The effective and safe drug for intractable pain in terminal cancer stage is : \nSelect and explain. \nA. Injectable pethidine, B. Injectable ketamine, C. Oral Brufen, D. Oral Morphine', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' oral morphine [Reference Harrison 16th/e, p 58 (15th/e, page495)JFor control of pain in cancer patientsWHO has devised a simple and effective method for the rational titration of oral analgesia called the WHO ladderThe critical features of this approach are thatt/t is oralshould be given around the clock with supplemental doses as needed.The management of pain is done in following steps :Mild to moderate painNSAIDs such asAcetaminophen,asprin orKetoprofenwith or without an adjuvant such as glucocorticoid or amitriptylineWhen pain persists or increasesa weak opioid such as codeine or hydrocodone is addedPain that is persistent or that is moderate to severe at the outsetincrease the potency of opioids orhigher doses of morphine is given", 'role': 'assistant'}]