Kathy Hutchins/Hutchins Photo
05/21/2011 at 10:00 PM EDT
Jeff Conaway needs all the help and well-wishes he can get, according to Dr. Drew Pinsky.
The former Taxi
actor, who was hospitalized earlier this week
, is "not doing well today suddenly," Pinsky Tweeted
Saturday evening. The doctor later described Conaway's state as "tenuous."
Pinksy – who previously worked to help Conaway with his addiction to cocaine, painkillers and alcohol on Celebrity Rehab
– visited the actor Friday.
"Just visited Jeff Conaway. He is stable & looks like he will recover from his pneumonia," Pinsky wrote Friday evening. "Not an OD like press is alleging & certainly not dead."
However on Saturday, Pinsky said that Conaway, 60, had taken a turn for the worse. "[He is] still considered critical with #sepsis. Many people die from septic shock. yes, he is VERY tenuous," wrote Pinsky. "My hopes & prayers r with him & his family! … Yes, we all need to pray for him."
A rep for the actor tells PEOPLE that "the use of painkillers and prescription drugs" – not an overdose – led to Conaway being found unconscious in his home.
"In any event, there is some improvement," the rep added, "and we are hopeful at this time."