Wise boy, your son! I'm glad you're starting oral route meds. He will feel quite nauseated from them unless he eats something solid with them. Peanut butter, nuts, ice cream (the real thing) a glass of whole milk with a banana, something to quiet that response, which can be pretty unpleasant and surprising if you're not prepared.
I was given celebrex twice a day for a month plus 2 tabs oxycodone/tylenol 5/325 every 4 hours for the first two days, then every 6 hours from then on. I wore ice, and spent very little time actually sitting up in a chair for two weeks. I sat sideways in the couch so my legs would be semi elevated at all times. Wearing, as I cannot emphasize often enough, ice

Ice literally numbs the area, and with anterior you don't have to sit on it!
Returning to the meds I took, I was able easily to titrate my dosage because the pills were scored for splitting. Rather than wait longer between what quickly became a sickeningly large dose of narcotic, I'd take, say, 1 1/2 oxy+1/2 of a 325 tylenol on the same every-6-hours schedule. I can't tolerate narcotics for long!
Then as I tapered over the weeks I'd just subtract percoset (the oxycodone I had) one-half pill at a time, putting in an equivalent amount of tylenol. The night dose remained highest longest-- I'd theoretically be asleep so not nauseated. Theoretical sleep is what you get at night for quite some time. Real sleep happens during the frequent nap attacks!
I aimed for, and was extremely fortunate to mostly achieve, pain of 1-2 almost all the time.
I think of your son frequently-- does he know he's got all these extra mamas and grandmas rooting for him?
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