Jeff Conway overdose, in critical condition

Jeff Conway is having a tough time.

The actor who rose to fame thanks to his roles in Grease and the TV seriesTaxi is in critical condition following an apparent overdose.

Sources close to Conway told the Los Angeles Times newspaper that he’s being treated at Encino Hospital Medical Center with pneumonia; he is currently unconscious.

Conway began using drugs in the mid-1980s, and in 2008, he appeared on VH1′s Celebrity Rehab with Dr. Drew, where he sought treatment for addictions to cocaine, painkillers and alcohol.

He frequently threatened to quit the show and also refused to end his relationship with his co-dependent girlfriend, Vikki, who also used prescription opiates.

Conway has previously claimed he kicked his drug habit by practicing the controversial religion of Scientology.

“I’ve been doing Scientology…my doctor was like, Holy cow, he says whatever you’ve been doing keep doing it because it’s really working,” he said.