You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which of the following is least narcotic opioid? and explain in detail?
Papaverine is devoid of opiod or analgesic activity. Morphine and codeine are natural opium alkaloids and heroin a semi synthetic derivative. Hence all three have good narcotic action. Ref: KD Tripathi 8th ed.