One medic revealed how, at the end of a long shift, he accidentally jabbed himself with a needle he had used to take blood from a baby whose mother had HIV.
The non-consultant hospital doctors (NCHDs) are working the exhausting hours despite EU rules prohibiting the practice.
Dr Patrick Kelly told RTE's Prime Time about how he "almost killed a patient".
"I had been working for 13 days in a row in a hospital.
"I had only been out of the hospital for eight, nine, 10 hours at most. I had given the wrong medication to a patient and it took a few minutes to realise I made a mistake.
"Luckily, I was able to reverse it and the patient suffered no ill outcome," he said.
He also spoke about a terrifying incident when he accidentally stuck a needle into his own hand.
"I once worked about 26/28 hours and I had taken bloods from a baby who had been born that night from a mum who had HIV and I became distracted while taking the blood and accidentally stuck the needle into my own hand," he said.
"I went to the emergency department, got very good treatment but the problem was they didn't have the drugs necessary for me to take in that emergency department and so I had to drive 45 minutes to another hospital.
"After being awake for 29 hours, I had to drive on the motorway to get these tablets to take. I had to wait 24 hours to hear that the baby had the all-clear but I had to wait six months before I was given the all clear," he revealed.
Dr John Donnellan said he can begin work on a Friday morning at 8am and work right through to 11pm or midnight that night.
"You're back in again during the night on Friday night, back in again on Saturday morning, work all day through on Saturday .... and again on Saturday night you're waiting on the phone to ring," Mr Donnellan said.
Dr Laura McCarron believes patients are not aware how many hours they have been working.
"If you asked them beforehand -- if you said to them -- 'hello my name is such and such, this is my 25th hour on my shift, are you happy with me to proceed with your care?', I can guarantee you most people would nearly say no," she said.
Dr Gillian Judge said she stopped driving after she fell asleep on the northbound lane of the M50 coming home from work one day.
She hasn't driven since.
It gets to 3am or 4am and "you begin to see double", Dr Niall Kelly said. "I've been told by a patient that I'm falling asleep.
"I was so tired I hadn't even realised I was falling asleep.
"The patient just said they were looking at me quite worried. I was repeating the questions again and again and again."
Dr McCarron questioned how "anybody could make a competent decision" after so many hours.
Dr Donnellan said: "I remember one specific incident where I got called by a nurse to see a patient who needed a line put in. It was something minor but I actually could not go I was that tired.
"I was rooted to the spot. You're just physically exhausted."
Barry O'Brien, HR director with the HSE, praised the NCHDs who spoke out and said the organisation was attempting to resolve the issue of working hours.