Is codeine and hydrocodone the same on a drug test?

Yes... shows up as opiate's. But if you have to take a drug test and don't want it to show the night before, drink a lot of Dr. Pepper make sure you drink 1-2 20 oz of DR. Pepper thirty minutes before the test. Also and it will show caffeine, and that ingests DR. Pepper and absorbs the codeine.

However, the best advice would be to not take it in the first place, or at least not before a drugs test. (Without a prescription at least..)