She also responded to criticism from Michael Fishman, who played her on-screen son D.J. on "Roseanne."
"Please leave me alone, thanks," she wrote.
Fishman said he was "devastated" Tuesday "not for the end of the Roseanne show, but for all those who poured their hearts and souls into our jobs, and the audience that welcomed us into their homes."
"The words of one person do not exemplify the thinking of all involved," he wrote.
Barr responded to the message early Wednesday by accusing Fishman of throwing her "under the bus."
Update 12:15 p.m. EDT May 30, 2018: The makers of Ambien responded Wednesday to a since-deleted tweet posted by Barr, in which she claimed that she was "ambien tweeting" when she posted a message widely deemed as racist to Twitter one day earlier.
“While all pharmaceutical treatments have side effects, racism is not a known side effect off any Sanofi medication,” representatives of Sanofi, the pharmaceutical company that manufactures Ambien, wrote on Twitter.
Ambien is a prescription sleep aide. According to prescribing information from Sanofi, the most common side-effects of the drug are drowsiness, dizziness, “drugged feelings” and diarrhea.
Update 11:50 a.m. EDT May 30, 2018: President Donald Trump responded to the cancellation of "Roseanne" on Wednesday.
“Bob Iger of ABC called Valerie Jarrett to let her know that ‘ABC does not tolerate comments like those’ made by Roseanne Barr,” the president wrote. “Gee, he never called President Donald J. Trump to apologize for the HORRIBLE statements made and said about me on ABC. Maybe I just didn’t get the call?”
Iger, who serves as chairman and CEO of Disney, the company that owns the ABC television network, said Tuesday in a tweet that "there was only one thing to do here, and that was the right thing."
Update 1:50 a.m. EDT May 30, 2018: Roseanne Barr continued to tweet late Tuesday and early Wednesday following her show's cancellation in the wake of a racist tweet.
"I deeply regret my comments from late last night on Twitter," Barr said in a statement shared by BuzzFeed's Kate Aurthur, which Barr retweeted. "Above all, I want to apologize to Valerie Jarrett, as well as to ABC and the cast and crew of the 'Roseanne' show. I am sorry for making a thoughtless joke that does not reflect my values – I love all people and am very sorry. Today my words caused hundreds of hardworking people to lose their jobs. I also sincerely apologize to the audience that has embraced my work for decades. I apologize from the bottom of my heart and hope you can find it in your hearts to forgive me."
She also asked fans to stop defending her.
"It's sweet of you 2 try, but ... losing my show is 0 compared 2 being labelled a racist over one tweet – that I regret even more," she tweeted.
Barr implied that the late hour of her offensive tweet and an insomnia drug may have impaired her judgment.
"It was 2 in the morning and I was Ambien tweeting," she wrote, later adding that she has "done weird stuff" while taking Ambien.
She commented on networks pulling "Roseanne" reruns from airwaves, asked followers not to boycott ABC and said she would continue to defend herself.
Update 11:30 p.m. EDT May 29, 2018: Roseanne Barr issued another apology via Twitter late Tuesday night after ABC cancelled her rebooted show earlier in the day following a Twitter rant and racist tweets.
“Don't feel sorry for me, guys!” Barr said in a short tweet just before 11:30 p.m.
“I just want to apologize to the hundreds of people, and wonderful writers (all liberal) and talented actors who lost their jobs on my show due to my stupid tweet,” she said.
Barr also said she’s guesting on the Joe Rogan Experience podcast Friday, where she may address the uproar over her tweets and the cancellation of her show.
Update 10 p.m. EDT May 29, 2018: Former top Obama administration adviser Valerie Jarrett responded to a racist tweet Tuesday by actress-comedian Roseanne Barr that led to the cancellation of Barr's rebooted TV show "Roseanne."
In an interview on MSNBC Tuesday night, Jarrett said the incident offered a "teaching moment."
She said she’s more concerned about racism directed against those who don’t have a support system to help them deal with it.
"I'm fine. I'm worried about all the people out there who don't have a circle of friends and followers who come right to their defense. The person who is walking down the street minding their own business and they see somebody cling to their purse, or run across the street, or every black parent I know who has a boy who has to sit down and have a conversation -- the talk -- as we call it. As you say, those ordinary examples of racism that happen every single day," Jarrett said.
She also said she supported the cancellation of the show and Disney CEO Bob Iger called her before ABC publically announced its decision to cancel "Roseanne," according to Slate.
Original story: Barr was heavily criticized after she wrote Tuesday in a since-deleted tweet that "Muslim brotherhood & planet of the apes had baby=vj."
The comment was in reference to Valerie Jarrett, a black woman who previously served as a top aide to President Barack Obama.
The tweet quickly drew backlash, with critics including the Rev. Al Sharpton calling it racist.
Barr apologized to Jarrett hours after posting her initial tweet as backlash to her comment mounted. She insisted that the tweet was “about (Jarett’s) politics and her looks” but did not address her reference to “Planet of the Apes.”
“I should have known better,” Barr wrote. “Forgive me -- my joke was in bad taste.”
ABC Entertainment president Channing Dungey called Barr’s initial tweet about Jarrett “abhorrent, repugnant and inconsistent with our values” in a statement announcing the show’s cancellation.
Bob Iger, chairman and CEO of Disney, the company that owns the ABC television group, said in a tweet "there was only one thing to do here, and that was the right thing."
Talent agency ICM Partners also announced Tuesday that the agency dropped Barr as a client, Variety magazine reported.
"We are all greatly distressed by the disgraceful and unacceptable tweet from Roseanne Barr this morning," agency officials said in a statement obtained by Variety. "What she wrote is antithetical to our core values, both as individuals and as an agency. Consequently, we have notified her that we will not represent her. Effective immediately, Roseanne Barr is no longer a client."
Barr’s on-screen daughter, actress Sara Gilbert, also condemned Barr’s comment, calling it “abhorrent” and adding that Barr’s views don’t “reflect the beliefs of our cast and crew or anyone associated with our show.”
Wanda Sykes, a black comedian who served as a consulting producer for “Roseanne,” announced earlier Tuesday that she would not be returning to the show.
The "Roseanne" revival, which premiered in March, was an unexpected major hit for ABC. It was particularly popular among many conservative viewers because Barr's character expressed support for President Donald Trump.
“Roseanne” originally ran from 1988 to 1997 and focused on the trials of the working-class Conner family.
The first episode of the series reboot garnered mostly positive reviews in March. It was seen by more than 25 million people, with delayed viewing counted in, numbers that are increasingly rare in network television.
The Associated Press contributed to this report.