My girlfriend had a rough night and decided she would take a handful of Tylenol PM (extra Strength). The pills contain 500 mg of acetaminophen and 25 mg of diphenhydramine. When asked first she said she took maybe 7 or 8. Now she is thinking it might have only been 6 or 7. It has been about eight hours since shes taking them and shes been sleeping. I have woken her up a few times to make sure she is alright. About an hour after taking them she tried making herself throw some of it up for about a half hour. I made her show me what came up and I could see that some of the pills came up but certainly not all of it. I made her eat what she would (two bowls of cereal). My question is if this is lethal? I know overdosing on this will cause a painful and slow death and Im at work now terrified at what I have read. I do not know why I did not take her to the hospital. She didnt want to go and I called a friend who says he has taken that many before but he is twice her age and twice her weight with a tolerance for them, but he said she would be fine. However I am now terrified for her health and wellbeing right now and am debating on leaving work possibly losing my job. The maximum she could have taken is probably 10 because I can account for what was left in the bottle. However she was being honest with me and although she doesnt know how many she took she says she is sure she didnt take ten . She thinks it was more like 6-8. My questions are how many pills can be taken at one time before it can be lethal and what are the signs of overdose ? She is only 19 years of age, 5ft, and 95 lbs.