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 All of the following are true about opioids except? and explain in detail?
Nalmefene is a derivative of Naltrexone and is orally effective and longer acting. Naltrexone, is a medication primarily used to manage alcohol or opioid dependence. An opioid-dependent person should not receive naltrexone before detoxification. It is taken by mouth or by injection into a muscle. Effects begin within 30 minutes. All the other statements are true. Ref: KD Tripathi 8th ed.