NBC has euthanized “Do No Harm” after two episodes before it could do any more ratings damage, while TV critics wondered what took the network so long.

 One week ago, the unveiling of this Jekyll/Hyde drama – brilliant neurosurgeon by day, nasty alter-ego by night – scored the lowest rating ever for an in-season scripted series unveiling by a Big Four broadcast network.

This week it fell another 22 percent among the 18-49 year old viewers who count with NBC ad sales execs, sealing its doom.

 The news came toward the end of a bad Friday for NBC; earlier in the day Christina Applegate announced she was bailing on the network’s plan to overhaul “Up All Night.”

NBC plans to morph the single-camera comedy about two new parents — played by Applegate and Will Arnett — into a multi-camera sitcom, with live studio audience, that paid more attention to the behind the scenes antics of an “Oprah”-esque show headlined by Maya Rudolph.

“It’s been a great experience working on ‘Up All Night’ but the show has taken a different creative direction and I decided it was best for me to move on to other endeavors,” Applegate said Friday in a statement.

 Web site Deadline reports NBC has put out feelers to Lisa Kudrow to take the role.