Taking opioids can change your anesthesia in a few important ways. Opioids are used during surgery and after surgery for pain control, but they can also cause sleepiness, nausea, constipation, low blood pressure, slow breathing, and confusion. They can also cause urinary retention, itching, and, in some cases, chest wall rigidity, which can make breathing harder. Because of these effects, your anesthesia team watches you closely and may use lower-opioid, opioid-sparing, or multimodal pain plans, which means using other pain methods too.

If you take opioids regularly, your body may be tolerant, which means the same drug may not work as well and you may need more pain medicine than expected. For patients on long-term opioids, the usual plan is to continue the baseline opioid dose through the perioperative period and after surgery to help prevent withdrawal. NYSORA also says to continue preoperative methadone or buprenorphine after surgery, along with multimodal pain care.

Opioids can also interact with other medicines. For example, opioid use is recommended to be avoided if you took an MAOI within 14 days, and caution is advised with SSRIs and SNRIs. Verify the exact plan with your surgical or anesthesia team in case they want something different for you.