If you can, try saying you mixed up the doses or thought that one painkiller helped so maybe more could help the physical pain go away. Or
ou could go the, ''I read it up on the internet that it cures (put reason here)''.
If you can, maybe say it was a dare or internet challenge for example to see how many pills you can take in a time span.
Or say you were doing the benadryl challenge but didnt have benadryl on hand so just subsituted it.