Adverse Side Effects
Common adverse side effects include constipation, nausea, sedation or drowsiness, and confusion or hallucinations. Somewhat less common side effects include dry mouth, sweating, urinary retention (which can result from constipation-related impactions or occur as a direct effect of opioids), pruritus, urticaria, seizures, syndrome of inappropriate antidiuretic hormone (SIADH), hypogonadism, and myoclonus.
Side effects are dose related and may be specific to a particular drug. With the exception of constipation, most side effects can be managed by rotating to another opioid or by adding an adjuvant analgesic, which allows for an opioid dose reduction.