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Your pain care team may recommend opioids to help you manage acute (sudden) or persistent pain. Read about opioids, some of their side effects and how to manage side effects of opioids.

Key points

  • One class of prescription pain relief medicines are opioids. These are strong medicines that must be taken as directed under close supervision.
  • Always take your medications exactly how your health-care provider prescribes them.
  • Always tell your health-care provider about all medications, natural products or recreational drugs you are taking and whether you would like to stop or change any medications. This way, you can minimize any side effects and harmful drug interactions.

Opioids are among the oldest, strongest and best-known prescription pain medications. Examples of opioids include morphine, hydromorphone, oxycodone and fentanyl.

There are many types and strengths of opioids—morphine is one of the strongest types—but they are all chemically related to the same poppy plant that produces opium.

Opioids are useful and commonly used for acute (sudden) pain, but they may not work as well for chronic (long-term) pain. Your pain care team will only start you on daily opioids for persistent pain after talking to you about their risks and benefits fully.

Side effects of opioids

Common side effects

Common side effects include:

  • constipation
  • nausea
  • vomiting
  • itching
  • drowsiness or sleepiness that can sometimes be serious enough to interfere with breathing

Because opioids cause drowsiness, do not drive until you know how they might affect you.

Less common but potentially serious side effects

Less common but more serious side effects include:

  • difficulty peeing
  • mood swings
  • vivid dreams
  • mild hallucinations and disorientation (mental confusion)
  • reduced levels of sex hormones (which can affect fertility) from long-term use

In high doses, opioids can sometimes make your pain worse instead of better.

How to manage the side effects of opioids

  • Health-care professionals can provide guidance and, if necessary, medications to help you manage the side effects of opioids. For instance, laxatives can be prescribed to ease constipation, or Zofran can be prescribed for nausea.
  • If you have a condition that affects your breathing, tell your health-care team so they can help you minimize the breathing-related side effects of opioids.
  • Also always tell your health-care team what other medications you take in case they may interact with opioids.

If opioids are prescribed for your treatment, the amount will depend on your weight and how much is needed for effective pain management. Your health-care providers will help you keep track of how much medicine you take so you stay within safe limits.

Opioids are powerful medications. Even if you take them exactly as prescribed and without any of the side effects listed above, they come with a number of risks. These are covered on the next page, Risks of opioids.

Last updated: September 25th 2023