Is Naltrexone an Opioid?

Naltrexone is an opioid antagonist. This means it works by blocking the opioid receptors in the brain. Naltrexone does not cause dependence and is not habit-forming.

When you drink, your body produces endorphins. These endorphins are actually endogenous opiates (a scientific way of saying opioids created by your body). For many people, the release of these endorphins and the pleasurable feeling they trigger translates into a desire to keep drinking.

Unfortunately, this endorphin system is not very sophisticated. Your biological functions can’t tell if you have a big meeting tomorrow or an important test coming up that week. As a result, it feels good just to keep drinking regardless of negative consequences.

When you take naltrexone, it blocks the opioid receptors that are activated by the endorphins and prevents the pleasurable sensation. This means your brain will no longer be rewarded for consuming alcohol. Over time, this can result in pharmacological extinction - meaning your brain loses interest in and no longer craves alcohol.

It’s important to note that while alcohol does generate a response in the opioid receptors, it is not the same as the direct effects of opioids such as heroin and prescription pain medication which fully activate these receptors. While naltrexone can be taken while drinking, it cannot be taken while using opioids. If naltrexone is taken while using opioids, it will cause immediate and severe withdrawal symptoms. If you’re taking opioids, naltrexone may still be an option for you but it should be discussed with your provider.