NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 8,079 terms related to cancer and medicine.
- rapid-onset opioid
- listen (… OH-pee-OYD)
- A substance that acts quickly 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. A rapid-onset opioid is a type of alkaloid.