TMZ, quoting law enforcement sources, reported that Lovato was found unconscious at her home and was treated with Narcan, an emergency antidote for suspected opioid and drug overdoses. A source has since told Variety and People magazines that Lovato is now in a "stable" condition.
Reps for Lovato did not immediately respond to EW's request for comment.
TMZ.com and US Weekly reported the 25-year-old singer, who has a history of substance-abuse issues, was suffering from a possible heroin overdose.
The lyrics read, "Mommy, I'm so sorry I'm not sober anymore, and daddy please forgive me for the drinks spilled on the floor".
They most recently broke up due to their intense schedules and after realizing she needed to work on herself and that they were better off as friends.
"I wanna be a role model, but I'm only human", she sang a few songs later.
Singles like "Skyscraper", "This Is Me" (a duet with ex-boyfriend Joe Jonas) and "Sorry Not Sorry" firmly established Lovato as a pop music star. Azalea revealed to ET that she knew about Lovato's relapse and was anxious someone would use the news against her, but said ultimately, she was proud of Lovato for sharing her struggle in "Sober".
Lovato was at her Hollywood Hills home at the time. However on Tuesday evening, Fox announced that the episode would be replaced with another new episode, stating: "Our thoughts go out to Demi and her family". "There is no one more honest or courageous than this woman".
And pop star Ariana Grande tweeted simply at Lovato, "I love you".