Australia bans sleeping pills at Olympics, report officials.
Australian Olympic Committee chief John Coates said prescription medications such as the powerful sleeping pill Stilnox would be banned for the first time at London after Hackett said he had developed a "heavy reliance" on the drug.
The AOC on Monday decided to amend its team medical manual "to make it absolutely unequivocal that we do not condone and indeed we prohibit the use of Stilnox by our athletes", Coates said Tuesday.
In North America the drug is marketed as Ambien.
Team doctors are being advised about the changes, which will also emphasise potential problems with caffeine use, and each discipline's squad will be briefed as they enter the Olympic village, Coates added.
"We are very worried about the vicious cycle of athletes taking caffeine as a performance enhancer and then needing to take drugs such as Stilnox to get to sleep," he told reporters in Sydney.
"We've done this because our primary obligation, our overriding obligation, is to protect the health of our athletes."
Coates said the changes were triggered by revelations from Hackett, dual gold medallist in the 1500m freestyle, that by the end of his career he had a "heavy reliance" on Stilnox prescribed by team doctors.
"I do not know the extent of it across the other sports and we're not going to conduct some sort of witch-hunt over this," the Australian official said.
But he said evidence about the possible risks of the drug justified the stance the committee was taking.
Coates said Hackett told him he was first prescribed Stilnox at the 2003 World Swimming Championships in Barcelona, and that it was doled out to swimmers as "normal practice" at the 2004 Athens Olympics.
Australian team doctors stopped prescribing the drug in 2007 after becoming aware of its sometimes dangerous side-effects, which can include walking and driving cars while asleep.
But Coates said that Hackett had told him there was "widespread use" of Stilnox even at the 2008 Olympics in Beijing. Hackett has said he stopped taking the drug when his career ended after the Beijing Games.
The AOC chief said athletes would be encouraged to practise meditation and other relaxation techniques in London.
If "in extreme circumstances" they still needed prescription sedatives, the short-acting and less addictive agent temazepam would be used, Coates said.