<unk>  is used to treat moderate to severe pain. It may be used by mouth or by injection into a vein, muscle, or under the skin. Effects generally begin within half an hour and last for up to five hours. Typically, long-term use is only recommended for pain due to cancer. A 2016 Cochrane review found little difference in benefit between<unk>  and other opioids for cancer pain.
Hydromorphone
Oxymorphone
Morphine
Nalorphine
Ropivacaine
Butorphanol
Oxymorphol
Sufentanil