What is highest dose of Celebrex is acceptable?

Hi, KTP!
It depends on what condition you're treating. This is a link to the recommended dosages:
https://www.drugs.com/dosage/celebrex.html
If you're taking these doses and they aren't effective for you let your doctor know and don't change your dosage on your own. You may be able to take more if your doctor recommends it or you may need to try a different medication.
Best regards,