What makes opioid medicines so dangerous?

Answer From Tyler S. Oesterle, M.D., M.P.H.

When used as directed by your doctor, opioid medicines safely help control severe pain, such as pain you may have after surgery. But there are risks when the medicines aren't used correctly.

What opioid medicines do

Opioids are a broad group of pain-relieving medicines that work with your brain cells. Opioids can be made from the poppy plant — for example, morphine (Duramorph, MS Contin, others). Or opioids can be made in a laboratory — for example, fentanyl (Actiq and Fentora). Other opioids that may sound familiar include codeine, hydrocodone (Vicodin), oxycodone (OxyContin, Roxybond, others). But there are many more.

Opioid medicines travel through the blood and attach to opioid receptors in brain cells. This blocks pain messages and can boost feelings of pleasure.

When opioid medicines are dangerous

What makes opioid medicines 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. And the pleasure or feeling high that results from taking an opioid can make you want to continue taking them more often and at higher doses. This can lead to addiction: Your brain and behavior are so badly affected that you no longer can control your use of opioids.

You can reduce your risk of dangerous side effects by following your doctor's instructions carefully and taking your medicine as prescribed. Make sure your doctor knows all of the other medicines and supplements you're taking. Talk with your doctor about the pros and cons of using opioids for pain relief. Ask about taking a different type of pain medicine or using another method of pain control if you feel that you're at higher risk of addiction.


Tyler S. Oesterle, M.D., M.P.H.

Mayo Clinic Minute: When are opioids OK to take?

Vivien Williams: This can be a common scenario: raiding the medicine cabinet for leftover painkillers after a sprained ankle or toothache. There's nothing wrong with popping an occasional opioid, right?

Mike Hooten, M.D. (Anesthesiology, Mayo Clinic): They are dangerous. They could have adverse effects that the individual doesn't even know about.

Vivien Williams: Including addiction or accidental overdose. So, when is it appropriate to take opioids?

Mike Hooten, M.D.: After an operation, opioids are highly effective.

Vivien Williams: Dr. Mike Hooten is a pain management specialist at Mayo Clinic.

Mike Hooten, M.D: After trauma, for example, severe trauma, opioids would be appropriate.

Vivien Williams: Dr. Hooten says opioids are also beneficial during procedures, such as colonoscopies. Problems happen when people take them without a prescription or for too long.

Mike Hooten, M.D.: If they are predisposed to develop addiction, either neurobiologically or from a behavioral perspective, then all of a sudden we are selecting the individuals who may go on to have long-term problems.

Vivien Williams: If you have pain, talk to your health care provider. For the Mayo Clinic News Network, I'm Vivien Williams.

Mayo Clinic Minute: Benefits, dangers of fentanyl

Vivien Williams: Fentanyl is a powerful painkiller.

Mike Hooten, M.D. (Anethesiology, Mayo Clinic): It is many, many times more potent than morphine, oxycodone, oxycontin, Vicadin, dilaudid, hydromorphine, all these types of drugs.

Vivien Williams: Mayo Clinic pain management specialist Dr. Mike Hooten says fentanyl is used in operating rooms, and to control pain after surgery. It also alleviates pain for advanced cancer patients.

Mike Hooten, M.D.: The use of fentanyl for chronic pain, I think, is avoided by many thoughtful practitioners for a number of reasons. Number one, it's high potency.

Vivien Williams: Number two, fentanyl, which is delivered via IV, a patch or in a lozenge, can be dangerous if used inappropriately.

Mike Hooten, M.D.: The reason for that is the sedative effects.

Vivien Williams: If you take too much, combine it with certain other medications, or drink alcohol …

Mike Hooten, M.D.: It clearly can compromise respiratory function, and that is really the start of the accidental overdose cascade.

Vivien Williams: For the Mayo Clinic News Network, I'm Vivien Williams.

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Aug. 26, 2023 See more Expert Answers

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