How Opioids Like Fentanyl Create Euphoria in the Brain

In order to understand how opioids work, it’s important to know how your body feels pain. The process begins when something harmful happens to your body. Information about this harm is converted to a nerve signal. The signal passes along nerves to your spinal cord and brain. In your brain, the signal is perceived as pain.

Opioid drugs affect how you feel pain. They attach to structures, called opioid receptors. These receptors are found on cells in your brain, spinal cord, and other areas of your body. Opioids act on these receptors to make you feel less pain. These drugs also have different effects in other areas. For example, opioids act on the reward pathway in your brain. This causes a release of a chemical called dopamine that results in a happy feeling, or “high.”

Opioids may also cause slower breathing. And, they may cause reduced motion of your intestines, resulting in constipation. For most people, when opioids are taken as prescribed for a short time, they are fairly safe and effective. But, these drugs can be taken in ways that weren’t prescribed, such as taking too many, taking them to get high, or giving them to someone else.

Misusing these drugs can raise your risk of developing drug tolerance, dependence, addiction, and overdose. Tolerance means the drug is less effective over time. This can happen when opioid receptors become less sensitive to the effects of the drug. As a result, more of the drug needs to be taken for you to get pain relief.

Dependence happens if a person has symptoms when they stop using the drug. When the drug is removed, or withdrawn, you feel sick. This sickness is called withdrawal. Opioid withdrawal has flu-like symptoms that include restlessness and anxiety, muscle aches, inability to sleep, watery eyes and runny nose, nausea and vomiting, stomach cramps and diarrhea, and dilated, or widened, pupils.

Opioid addiction is a brain disease where you have an overwhelming craving for the drug. You can’t stop taking the drug despite the harm it may cause you. Addiction is not the same as dependence. You can be tolerant of a drug or dependent on a drug, without being addicted to it. Finally, opioid overdose is a condition where taking too much of the drug can cause life-threatening symptoms, or even death.

The symptoms of opioid overdose can include confusion, feeling very sleepy or not alert, nausea and vomiting, constricted, or small, pupils, unconsciousness, slow or stopped breathing, and death.

According to the Centers for Disease Control, over one hundred Americans die each day from opioid overdoses. If you have questions about opioids, or if you or someone close to you needs help for an opioid use disorder, talk to your healthcare provider.