Final answer:
The most common side effect of oxycodone is constipation.
Step-by-step explanation:
The most common side effect of oxycodone, a prescription opioid used for pain relief, is constipation. In addition to constipation, other side effects of prescription opioids include pruritus (itching), vomiting, and delirium. It is important for the client to be aware of these side effects and take proper measures to manage them.