Drug misuse leads to over 500,000 deaths yearly. In 75% of these cases, opioid overdose is a factor. Specifically, according to recent estimates, 68,630 Americans lost their lives to opioid overdose in 2020.
Research suggests timely treatment — with opioid antagonists — can prevent opioid overdose deaths. A multi-site community study demonstrated increased survival rates in cases of opioid overdose treated with opioid antagonists. Similarly, in another study, naloxone (an opioid antagonist) reversed opioid overdose in 93.5% of cases.
This article discusses what an opioid antagonist is, how it works and how it can help you. Read on to learn more.
What is an Opioid Antagonist?
The term 'antagonist' refers to any substance that interferes or inhibits the action of another chemical. Thus, opioid antagonists are medications that prevent opioid activity in the body.
Opioid Antagonists, Agonists, Partial Agonists, and Mixed Agonists/Antagonists: What Are Their Differences?
Biochemists classify opioids (and related medications) into four groups based on how they interact with opioid receptors:
- Full agonists: These are potent activators of opioid receptors. Examples include fentanyl, heroin, morphine, and oxycodone.
- Partial agonists: These only partially activate opioid receptors. Buprenorphine is an example.
- Antagonists: These bind opioid receptors but do not activate them. Examples include naloxone and naltrexone.
- Mixed agonists/antagonists: These function as antagonists for some opioid receptors and as agonists for others. Examples include butorphanol, nalbuphine, and pentazocine.
How do Opioid Antagonists work?
Opioids work by binding to specific receptors in the body in the brain (central receptors) and the nervous system (peripheral receptors). Opioid antagonists block opioid function by occupying opioid receptors. This prevents the body from responding to endorphins and opioids.
Understandably, opioid antagonists only work if an individual already has opioids in their system. This is because while opioid antagonists occupy opioid receptors, they do not activate them.
Types of Opioid Antagonists
Researchers classify opioid antagonists into two categories — central and peripheral — based on the receptors they bind.
Central opioid antagonists occupy opioid receptors in the brain. These include:
Peripheral opioid antagonists preferentially bind to opioid receptors outside the brain — mainly in the lungs and the gastrointestinal tract. This is because peripheral opioid antagonists can not easily cross the blood-brain barrier. Examples include: