A substance used to treat moderate to severe pain. Opioids are like opiates, such as morphine and codeine, but are not made from opium. Opioids bind to opioid receptors in the central nervous system. Opioids used to be called narcotics. An opioid is a type of alkaloid.
( OH-pee-OYD )
Source: NCI Dictionary of Cancer Terms
Search the Glossary of Medical Terms
Newsletter
Sign up for the QuackTrack.org newsletter below!