I have studied your case,
Oxyicodone can cause gastric irritation but swelling over body is not reported.
I will suggest to do complete cardiac and renal check up to look for any abnormality.
If malignancy is suspected then further investigation may be required.CT scan
of abdomen and if required PET scan will help.
Hope this answers your query. If you have additional questions or follow up queries then please do not hesitate in writing to us. I will be happy to answer your queries.
Wishing you good health.