On Friday, the Daily Mail published video showing the 56-year-old Nationals MP on the ground in the inner suburb of Braddon after sitting on a planter box and falling off.
The clip has since gone viral and raised questions about the former deputy prime minister’s fitness to sit on the front bench.
“Look, obviously I made a big mistake,” Mr Joyce told Seven’s Sunrise program on Monday.
“There’s no excuse for it.
“There’s a reason … they say certain things happen to you if you drink (while on medication) and they were absolutely, 100 per cent, right.”
The government has called on the coalition to answer for Mr Joyce’s actions, with Finance Minister Katy Gallagher saying the situation was “incredibly sad”.
“These things do nothing for the profession of politicians … it confirms, in people’s minds, the public’s minds, negative association with politics, and I think that’s a real shame,” she told ABC radio.
“But personally, I hope he gets the help he needs because it’s a very unusual position for someone of that age to be in.”
Nationals leader David Littleproud said Mr Joyce had matters he needed to work through but hoped he would return to work in the afternoon or later in the week – though the party’s meeting is planned for Monday.
“This is something that he’s deeply embarrassed about,” Mr Littleproud told Sky News.
“He’s made that very clear that this isn’t normal behaviour that he undertakes and there are extenuating circumstances surrounding that and obviously, we will support him in making sure that, anything that he does need, he gets.”
Asking if he was angry someone filmed the incident rather than helping him, Mr Joyce said “that’s a question for them”.
“To me, the good Samaritan was the Indian taxi driver who pulled over as I was walking home and said ‘do you need a lift mate?’, which I obviously did,” he said.