He also said he was lucky he got sober before becoming famous and had the money to feed his addiction.
"I have so much empathy for these young actors that are 19 and all of a sudden they're beautiful and famous and rich," he said in the interview. "I'm like, 'Oh my God, I'd be dead."'
The actor said he kicked the habit for 23 years and had remained sober until May 2013 when he briefly relapsed and returned to rehab after admitting to snorting heroin.
Hoffman's death comes one day after representatives issued a statement denying a report about the actor's death earlier in the week.
He is succeeded by his girlfriend, costume designer Mimi O'Donnell, their son, Cooper, 10 and two daughters, Tallulah, 7, and Willa, 5.