Opioids are powerful painkilling drugs that are usually prescribed to treat acute pain or cancer pain. In some cases, these morphine-like medications may be used to treat chronic pain that is not related to cancer, such as severe joint pain or pain related to nerve damage.

Opioids include natural opiates (derived from the opium poppy plant) and synthetic narcotics. Exactly how they relieve pain is unclear, but they appear to:

• Block pain messages to the brain
• Change the brain’s interpretation of pain

Although opioids are effective in providing pain relief, many physicians do not prescribe them because they fear their patients may become addicted and because of stringent regulations by the U.S. Drug Enforcement Agency.