Sean Penn was drugged up and live on TV last night

Sean Penn chain-smoked his way through his Late Show appearance last night and jokes that he was "Job security for oncologists."

The actor appeared disheveled talking with Stephen Colbert. At the outset, Penn admitted, "You’ve inherited a little of the Ambien I had to take to get to sleep after a red-eye last night."

Colbert asked for clarification, "So you’re on the Ambien train right now?" The rambling interview affirmed that indeed Penn was on prescription drugs.