What Is a Partial Opioid Agonist?
A partial agonist is an opioid that produces less effect than a full agonist when it binds to opioid receptors in the brain. The way different opioids work can be explained using a lock and key example. Receptors are like a lock to a door. Only the right key will fit the lock, and only opioid-like drugs fit opioid receptors. • With a full opioid agonist such as oxycodone, hydrocodone, morphine, methadone, or heroin, the key fits the lock, opens the door wide, and produces full opioid effects (the feeling of euphoria, or being high, as well as the side effects) • With a partial opioid agonist such as buprenorphine, the key fits the lock but doesn’t open the door all the way, so it produces less than full opioid agonist effects and, at the appropriate dose, blocks other opioids from opening the door fully • An opioid antagonist such as naltrexone or naloxone fits in the lock but does not open the door At appropriate doses Suboxone can: • Help to suppress withdrawal from prescription pain
