Coe wants cheats to be banned from the sport for four years instead of the two-year suspension used at the moment.
The organiser of the London Olympics, who is vice-president of athletics’ governing body the IAAF, also hinted that he would be prepared to become president of the IAAF or the IOC in a move to have a say in shaping the future of the sport.
Coe was speaking in the wake of last week’s revelations that America’s 100 metre sprinter Tyson Gay, the fastest man in the world this year, and former 100m world record holder Asafa Powell and Jamaican team-mate Sherone Simpson had failed drugs tests.
Coe, asked if the cheats should face life bans, said: “If I had the opportunity to implement that I would, but we must accept now that the legal inhibitor to being able to do that is profound.
“We are not going to be able to have life bans. That would be challenged and we would probably lose. We have to go back from two years to four years.
“The move from four years to two years did an inordinate amount of damage to my sport. It was not a sanction which was proportionate.
“Four years really does make people think. It is a big chunk of their career. Two years with some appeals is in reality only 18 months. Too many athletes have been prepared to take the risk.”
Coe was speaking on BBC Radio 5 Live’s Sportsweek programme and, while he admitted the failed tests were “depressing”, he believes it proves athletics has the will to track down the cheats.
Coe said: “Trust sits at the heart of this. I don’t think it has gone entirely. The big challenge is to go on fighting. This is not a fight we can afford to lose.
“The overall message is not a bad one. That is that we have the technology, we are intelligently testing. We are going after people and the Powell, the Tyson Gay and the other high-profile tests in the last few months are not random.
“If you step up testing and are far tougher about who you test and have better technology by the year, you are going to weed out the cheats. The message is if you are going to risk this we will pick up the abnormalities.
“If we are prepared to go after names and organisations in the sport at that level it shows we are serious.”
Asked if he would seek to become president of the IAAF or president of the IOC in a bid to clean up the sport, Coe said: “I’m working within the IAAF. If I get the opportunity at some stage to shape the future of sport of course I would want to do that.”
He added: “It’s the clean athlete we are here for. I don’t care how many cheats we weed out – the quicker we do it the better.”