Took a benadryl (diphenhydramine) and 1 percocet of 10/325 together. im dizzy & sleepy and i just threw up. i had another percocet about 5hrs before that is it overdose?

Hard to tell: The dose of Percocet is fairly small, so doubt that it is an overdoses as much as the typical nausea which can accompany opioid uses. The mixing of Benadryl (diphenhydramine) and Percocet can be lethal though, and should never be done! Perhaps the elevated dose of the principal metabolite, oxymorphone, twice a strong as oxycodone was the culprit.