What is a common adverse effect of opioid analgesics?

Opioid analgesics are known to cause constipation as a common adverse effect due to their action on the gut's opioid receptors. These receptors, when activated by opioids, lead to decreased gastrointestinal motility, resulting in slower transit time of bowel contents and increased water absorption, which ultimately leads to harder stools and difficulty in bowel movements. This effect is particularly notable because it occurs in nearly all patients who take these medications, regardless of their individual responses to pain relief. While nausea, drowsiness, and confusion can also occur with opioid use, constipation stands out as the most prevalent and predictable adverse effect, making it crucial for healthcare providers to educate patients about this possibility and to implement preventive measures, such as recommending fiber intake or laxatives if necessary.