Opioid

Opioid analgesics reduce pain transmission and alter the brain’s response to pain, primarily through opioid receptors in the central nervous system. The same receptor effects that produce analgesia can also suppress the medullary respiratory drive, slow gastrointestinal motility, cause sedation, and contribute to urinary retention. This shared mechanism explains why respiratory depression and constipation are predictable opioid toxicities rather than unrelated complications. Pain relief is not the only outcome to assess. A useful response means that pain becomes more manageable while the patient remains arousable, breathes adequately, and can perform an appropriate function, such as deep breathing, repositioning, mobilising, or resting. A lower pain score with new difficulty staying awake is not a successful therapeutic response. Respiratory depression is the danger experienced nurses notice first because it can progress quietly. The patient may become increasingly difficult to rouse before oxygen saturation falls, particularly when supplemental oxygen is being given. Count respirations, assess the depth and pattern of breathing, and observe arousability rather than relying on the monitor alone.