Former “Taxi” star Jeff Conaway, who apparently overdosed on painkillers about a week ago, remained in a coma today, and in a battle for his life, People magazine reported.

Conaway played Bobby Wheeler on the hit sitcom, and also had a high-profile role in the movie “Grease.” He has struggled with health problems and addiction, a battle that was fought publicly on the reality show “Celebrity Rehab.”

But his latest crisis took people close to the actor by surprise. "He seemed fine early last week," his manager, Phil Brock, told the publication. "He had spoken with his agent and his management team and even attended an autograph signing. He really seemed in fine spirits."

Brock expressed concern over how the current situation will play out. "Over the weekend, there was head movement, but there have not been any changes in his movement or condition since then," he said. "We are concerned it may have been an overdose but we have no way of knowing for sure."