The 63-year-old 'Rolling Stones' star slipped out of a palm tree in April 2006, as a result of which he suffered a head injury.
Ever since the accident, he has been on the drug that he is not allowed to mix with cocaine.
"Drugs I'm on now - the s**t I've gotta take because of the brain job, Dilantin. Means you can't take cocaine anymore. Which is fine with me," Contactmusic quoted him as saying.
"I mean, I haven't seen coke for, like, a year and a half. Big deal. Y'know I used to like my little bump here and there after meals. But now I can't do that anymore, so I don't do it no more. I still smoke like a f**king chimney. Get me some good weed," he added.