• By

    Dana Sparks

    What are opioids and why are they dangerous?

prescription medicine bottles on a pharmacy table, pain medicine

What opioid medications do
Opioids are a broad group of pain-relieving drugs that work by interacting with opioid receptors in your cells. Opioids can be made from the poppy plant, such as morphine (e.g., Kadian and MS Contin) or synthesized in a laboratory, such as fentanyl (e.g., Actiq and Duragesic).

Dr. Carrie Krieger, a clinical pharmacist in Medication Therapy Management at Mayo Clinic, says an opioid is a substance that binds to an opioid receptor. "When we talk about opioid medications, what we’re talking about is everything from natural substances, like morphine and codeine, to synthetic substances, like methadone or fentanyl. And, then, there are some that fall in between. We call those semisynthetic, and that includes oxycodone and hydrocodone, which are pretty commonly prescribed."

When used as directed by your health care provider, opioid medications safely help control acute pain, such as pain after surgery. There are risks, though, when the medications are used incorrectly.

How do opioid medications work?
When opioid medications travel through your blood and attach to opioid receptors in your brain cells, the cells release signals that muffle your perception of pain and boost your feelings of pleasure.

"There are different ways opioid medications can be administered," says Dr. Krieger. "Sometimes, it’s through a patch, or sometimes it’s through a pill that we take by mouth. But, ultimately, the opioid gets into the bloodstream and then travels to opioid receptors that are found in the brain. By binding to those receptors, they sort of dull our pain perception by binding to the receptor." Dr. Krieger says they also can produce an effect stimulating the reward center in the brain that causes that pleasure feeling.

Watch: Dr. Krieger discusses what makes opioid medications so dangerous.

Journalists: Broadcast-quality sound bites with Dr. Krieger are in the downloads.

How do opioids differ from over-the-counter pain medications?Acetaminophen (e.g., Tylenol) and some of the nonsteroidal anti-inflammatory drugs, also known as NSAIDs, including ibuprofen and naproxen, work by binding to a different receptor. "In the case of NSAIDs, they bind to a Cox-2 receptor, for example," says Dr. Krieger. "Those receptors have not – or those medications have not – been associated with developing dependence or a tolerance to the medication. Therefore, they’re not at risk for developing addiction associated with those medications."

What makes opioids so dangerous?
What makes opioid medications effective for treating pain also can make them dangerous. At lower doses, opioids may make you feel sleepy, but higher doses can slow your breathing and heart rate, which can lead to death. Also, the feelings of pleasure that result from taking an opioid can make you want to continue experiencing those feelings, which may lead to addiction.

"All medications are associated with a risk of side effects, and there’s no exception for the opioids," says Dr. Krieger. "But, particularly, there are certain side effects that make opioids more dangerous."

"When we administer opioids at lower doses, we can commonly see drowsiness or dizziness as a potential side effect, but when we give them at higher doses, they can lead to what we call respiratory depression, which means that our respiratory, or our breathing, is diminished," says Dr. Krieger. "And, likewise, our heart rate can be diminished. In extreme cases, we can suppress that so that a person doesn’t breathe, and that can lead to death."

"The other way that they are particularly dangerous is that they can lead to addiction," Dr. Krieger adds. "So, by stimulating this reward center or feeling of pleasure, it can make a person want to continue to experience that, and that’s what leads to addiction."

You can reduce your risk of dangerous side effects by following your health care provider's instructions carefully and taking your medication exactly as prescribed. Make sure your health care provider knows all of the other medications and supplements you're taking.

Find more health and medical information on mayoclinic.org. 

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