The Difference between Opiate Agonist and Antagonist Drugs

The Difference between Opiate Agonist and Antagonist Drugs

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If you turn on the news, it doesn’t take long to hear about the opiate crisis in the United States. There’s a lot of discussion about these drugs and how they behave. You may have heard the terms “agonist” and “antagonist” but not really understand them. Read on to learn more about the differences between these two categories of drugs.

Opiate Agonist

Agonist drugs are those that activate opioid receptors in the brain and other areas of the body. These drugs bind to receptors found on the cells of the brain and then cause a reaction. In the case of opiates, the when these drugs activate the receptors the result is that pain signals are blocked.

However, they can also cause side effects such as drowsiness, nausea, constipation, mental confusion and even cause a decrease in breathing rates. And when taken in higher doses they can cause euphoria, or a feeling of being high.

Over time, one can become addicted to an opiate drug. This happens because the more your body is exposed to a drug, the more it adapts to it. In other words, you need more and more of the drug to experience the same pain relief.

If this happens, you’ll experience withdrawal symptoms when you stop taking the medication. Symptoms can include restlessness, diarrhea, vomiting, sweats, and pain. Tapering down rather than stopping cold turkey is a way to minimize the experience of physical withdrawal.

When opiates are misused, as is often the case, it can lead to a higher risk of overdose. There is also a high risk of transitioning from prescription opioid dependence to heroin use and addiction.

An overdose of opiates can cause severe reactions, including death. It can cause your breathing rate to slow and even stop. This is especially true if you combine opioids with other drugs including alcohol.

Opiate Antagonist

Opiate antagonist drugs are those that actually attach to opioid receptors in the body, but don’t activate them. They block the effects of opioid agonists without causing a high. Some antagonists actually do produce a weak effect while others produce no effect at all.

Why would this be useful? In the case of opioid overdose, antagonist drugs can be used to reverse the symptoms and prevent death. This can be given during an acute episode.

But for long-term use these drugs are sometimes effective in treating opioid dependence. They block the euphoric feeling caused by opioids and by taking them, the individual is less likely to continue to abuse the opioid.

The most common antagonist drugs include Naloxone, Naltrexone, Narcan, Narcon, Narcotan, Vivitrex, and Zynol, though there are more than a hundred drugs on the market.

Many addiction treatment professionals believe that the use of antagonist drugs, particularly those that are long-acting, is a key to solving the problem of opiate addiction.

For example, Vivitrol is a medication that blocks opioid receptors for a month at a time. That allows a patient to go a month between visits to the doctor and decreases the likelihood of opioid relapse.