no lol you should be just fine from that much tylenol. the daily limit is 4000, so that would be 8 of the 5/500s. the itching is a side effect from opiates in general. just search on google "itching and hydrocodone" and im sure alot of shit will pop up. dont worry about it, your fine, just next time take some benadryl 20 mins before you pop the hydro.
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This Is from a iPhone app called I triage.it has everything about any drug you wanna know and its free, plus it has a symptom checker. Note one of the side effects is itching. Same with oxy. It gets worse in high doses but is generally not bad in low doses.
i think your fine, try to get the 10s next time if your going to take a higher dose if your worried about the tylenol. 7.5s would be better to. i itch from hydrocodones, i love it lol. When my opiate tolerance was lower i would still feel the hydrocodone buzz after i woke up, including the itches but not as intense as the night i dosed.