how many milligrams of hydrocodone can you take at one time?!

Taking the three at once isn't going to harm you...if you only do it once a day. It isn't the hydrocodone that that would be concerning but the tylenol. 500mgx3=1500 mg. The daily maximum dose os 2000 mgs. Tylenol can be very damaging to your liver. Be sure not to add any other meds that contains extra tylenol. If the hydrocodone isn't doing enough for the pain...talk to your doctor. He can prescribe a longer acting medication such a morphine extended relief. It lasts 8-12 hours. Another medication such as Vicodin or percocet can also be given with the morphine as needed for break thru pain. There is so much concern with tylenol with the higher doses of Vicodin. Good luck and I hope you can get some pain relief.
Ps: with taking more of the hydrocodone...it also raises your tolerance level and then more medication is needed for true pain relief.

Experience (my fiancée is on hydrocodone for pain relief for extreme case of Crohns disease)