How does oxycodone differ from hydrocodone? How powerful is fentanyl compared to morphine? A working knowledge of opioids is important for clinicians who treat patients with chronic pain. Opioids include:

• Morphine, derived from secretions of the poppy plant. The strength of other opioids is usually given as “morphine equivalents,” based on equal weights.
• Codeine, chemically modified from morphine. Codeine is about one-sixth as strong as morphine.
• Heroin is derived from morphine. It is 5 times as strong as morphine, and has no approved human use.
• Hydrocodone is derived from codeine. It is about as strong as morphine.
• Hydromorphone is derived from morphine. It is 4 times as strong as morphine.
• Oxycodone is derived from codeine. It is 1.5 times as strong as morphine.
• Oxymorphone is derived from morphine. It is 3 times as strong as morphine.
• Fentanyl is a synthetic opioid. It is about 100 times as strong as morphine. Because of the potential for overdose from oral medication, it is delivered with a transdermal patch.
• Carfentanil is 10,000 times as strong as morphine, and has no approved human use.

An online dose equivalent calculator can be used to determine equivalent analgesic effects for different opioids. A compelling visual comparison of opioid strengths can be found here. More information from Quest Diagnostics about prescription opioids can be found here.