The California addiction specialist called in to help Prince in his last days prescribed thousands of dollars a month in pills to former Guns N’ Roses drummer Steven Adler when he was trying to kick heroin, Adler’s mother charges.

In her new book, “Sweet Child of Mine,” Deanna Adler writes about being jolted by the news of Prince’s April 2016 death and his link to Dr. Howard Kornfeld.

“I am so blessed that my son is still alive,” despite the doctor “overprescribing” meds to him, Adler told The Post in an interview last week. Her memoir is out Friday.

Kornfeld had been hoping to treat Prince at his Rehab Without Walls clinic in Marin County, ­Calif., after being called by one of the singer’s reps on April 20, 2016.

The doctor sent his son to Minneapolis the next day, carrying doses of the opiod-rehab med Suboxone, purportedly to explain the program to Prince. Kornfeld, who specializes in opioid addiction, was to arrive on April 22.

But when Kornfeld’s son reached Prince’s Paisley Park mansion, the 57-year-old “Purple Rain” singer was unconscious in the ­elevator. The cause of death was self-administered overdose of the opioid painkiller Fentanyl.

“The hope was to get him stabilized in Minnesota and convince him to come to Recovery Without Walls,” William Mauzy, a lawyer for the Kornfelds, said in May.

Steven Adler, now 52, once described as “the most self-destructive rock star ever,” turned to Kornfeld after he was busted for driving under the influence in 1995.

After several weeks in the hospital to detox, Steven was released to continue treatment on his own at a nearby rental.

His mother writes she was shocked when she received the first pharmacy bill for more than $2,000.

“What kind of scam was this?” she writes. “What the hell was going on?”

The book includes a list of 63 prescriptions her son was prescribed in one month, including Prozac, Valium amd Antabuse — used to treat alcoholism — and lithium, for bipolar disorder.

She said she researched the meds and learned why they were prescribed.

“But I could not fathom, and they never answered to my satisfaction, why they needed to have two different types of psychotics, or three different sleeping-aid medications or five different types of pain killers,” she writes. “Even I know you shouldn’t mix Darvocet, Percodan and Tylenol with codeine.”

She complained to the American Medical Association and the California Board of Pharmacology, which found no evidence of impropriety, she writes.

Steven Adler completed three months of treatment with Kornfeld and immediately relapsed, visiting his drug dealer before he even returned to his Los Angeles home, his mother writes.

He is now sober, Deanna says, and recently joined Guns N’ Roses for several shows on its current tour.

Kornfeld’s office said he would not comment on Adler.