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.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.

Aug. 26, 2023 See more Expert Answers

See also

  1. Medication-free hypertension control
  2. Alcohol: Does it affect blood pressure?
  3. Alpha blockers
  4. Ambien: Is dependence a concern?
  5. Angiotensin-converting enzyme (ACE) inhibitors
  6. Angiotensin II receptor blockers
  7. Antidepressant withdrawal: Is there such a thing?
  8. Antidepressants and alcohol: What's the concern?
  9. Antidepressants and weight gain: What causes it?
  10. Antidepressants: Can they stop working?
  11. Antidepressants for children and teens
  12. Antidepressants: Side effects
  13. Antidepressants: Selecting one that's right for you
  14. Antidepressants: Which cause the fewest sexual side effects?
  15. Anxiety: A cause of high blood pressure?
  16. Atypical antidepressants
  17. Automated external defibrillators: Do you need an AED?
  18. Beta blockers
  19. Beta blockers: Do they cause weight gain?
  20. Beta blockers: How do they affect exercise?
  21. Bipolar disorder
  22. Bipolar disorder and alcoholism: Are they related?
  23. Bipolar disorder in children: Is it possible?
  24. Bipolar medications and weight gain
  25. Bipolar treatment: I vs. II
  26. Blood pressure: Can it be higher in one arm?
  27. Blood pressure chart
  28. Blood pressure cuff: Does size matter?
  29. Blood pressure: Does it have a daily pattern?
  30. Blood pressure: Is it affected by cold weather?
  31. Blood pressure medication: Still necessary if I lose weight?
  32. Blood pressure medications: Can they raise my triglycerides?
  33. Blood pressure readings: Why higher at home?
  34. Blood pressure tip: Get more potassium
  35. Caffeine and hypertension
  36. Calcium channel blockers
  37. Calcium supplements: Do they interfere with blood pressure drugs?
  38. Can whole-grain foods lower blood pressure?
  39. Central-acting agents
  40. Choosing blood pressure medicines
  41. Clinical depression: What does that mean?
  42. Depression and anxiety: Can I have both?
  43. Depression, anxiety and exercise
  44. What is depression? A Mayo Clinic expert explains.
  45. Depression in women: Understanding the gender gap
  46. Depression (major depressive disorder)
  47. Depression: Supporting a family member or friend
  48. Diuretics
  49. Diuretics: A cause of low potassium?
  50. High blood pressure and exercise
  51. Free blood pressure machines: Are they accurate?
  52. Home blood pressure monitoring
  53. Heart arrhythmia
  54. Heart Rhythm Conditions
  55. High blood pressure (hypertension)
  56. High blood pressure and cold remedies: Which are safe?
  57. High blood pressure and sex
  58. High blood pressure dangers
  59. How opioid use disorder occurs
  60. How to tell if a loved one is abusing opioids
  61. What is hypertension? A Mayo Clinic expert explains.
  62. Hypertension FAQs
  63. Hypertensive crisis: What are the symptoms?
  64. Insomnia
  65. Insomnia: How do I stay asleep?
  66. Insomnia treatment: Cognitive behavioral therapy instead of sleeping pills
  67. Intervention: Help a loved one overcome addiction
  68. Isolated systolic hypertension: A health concern?
  69. Kratom: Unsafe and ineffective
  70. Kratom for opioid withdrawal
  71. Lack of sleep: Can it make you sick?
  72. L-arginine: Does it lower blood pressure?
  73. Low blood pressure (hypotension)
  74. Male depression: Understanding the issues
  75. MAOIs and diet: Is it necessary to restrict tyramine?
  76. Marijuana and depression
  77. Medications and supplements that can raise your blood pressure
  78. Menopause and high blood pressure: What's the connection?
  79. Mental health: Overcoming the stigma of mental illness
  80. Mental health providers: Tips on finding one
  81. Mental illness
  82. Monoamine oxidase inhibitors (MAOIs)
  83. Natural remedies for depression: Are they effective?
  84. Nervous breakdown: What does it mean?
  85. Opioid stewardship: What is it?
  86. Pain and depression: Is there a link?
  87. Picnic Problems: High Sodium
  88. Prescription drug abuse
  89. Prescription sleeping pills: What's right for you?
  90. Pulse pressure: An indicator of heart health?
  91. Reactive attachment disorder
  92. Resperate: Can it help reduce blood pressure?
  93. Selective serotonin reuptake inhibitors (SSRIs)
  94. Serotonin and norepinephrine reuptake inhibitors (SNRIs)
  95. Sleep deprivation: A cause of high blood pressure?
  96. Stress and high blood pressure
  97. Tapering off opioids: When and how
  98. Teen depression
  99. Teen drug abuse
  100. Nutrition and pain
  101. Pain rehabilitation
  102. Self-care approaches to treating pain
  103. Treatment-resistant depression
  104. Tricyclic antidepressants and tetracyclic antidepressants
  105. Unexplained weight loss
  106. Valerian: A safe and effective herbal sleep aid?
  107. Vasodilators
  108. How to measure blood pressure using a manual monitor
  109. How to measure blood pressure using an automatic monitor
  110. What is blood pressure?
  111. Vitamin B-12 and depression
  112. Can a lack of vitamin D cause high blood pressure?
  113. White coat hypertension
  114. Wrist blood pressure monitors: Are they accurate?
  115. Mayo Clinic Minute: Do not share pain medication
  116. Mayo Clinic Minute: Avoid opioids for chronic pain
  117. Mayo Clinic Minute: Be careful not to pop pain pills