What is the most common side effect of opioids?
The most common side effect of opioids is opioid-induced constipation (OIC). The rate of constipation with chronic use of opioids for noncancer pain may be as high as 90%, and remains an issue even with intermittent regular use. Prevalence is no doubt elevated, because OIC is the only opioid side effect that does not improve over time with development of tolerance. Moreover, as tolerance develops, doses of opioids are often escalated, which serves to further enhance OIC.