Sheen was taken to a New York hospital earlier this week after cops found him in a posh Manhattan hotel, naked, intoxicated and extremely agitated with a porn star. He was already on probation an incident last Christmas in which he was charged with assaulting his then-wife, Brook Mueller.
Downey had his own trouble with drugs and alcohol, serving a year in prison in 1999 and going through rehab numerous times before finally getitng back on track. Now he commands as much as $20 million per movie.
When asked by E! how Sheen could duplicate his triumph over substance abuse, Downey said he will help if he can.
"It's different for everybody," he said "The weird thing is that someone who's been through it is expected to talk about it. I'd rather just talk to them. Maybe they don't want to talk to me. But I'd like to talk to Charlie. I've known him for ages."