Natasha Lyonne Says She Took Sleeping Pill Before Being Escorted Off Flight

Natasha Lyonne's explaining exactly why she may have seemed out of it when airport authorities forced her off a recent Delta flight ... it sounds like she took a sleeping pill just a little too early.

In response to an article detailing the incident, Natasha admitted she took a Lunesta -- a prescription drug for insomnia -- to get some sleep on a Delta redeye from L.A. to New York.

Lyonne says she had to hit the ground running in the city -- she had an interview with Drew Barrymore she needed to do once she touched down -- so she popped the pill and then boarded the plane "eager for a nap."

Unfortunately, she says ICE detained her -- a "sign of the times," she supposes -- and she thanks everyone for their love and support.

She specifically notes she's never had an issue with TSA or Delta before ... and she apologizes to any passengers who were delayed by the detention.

As we told you ... witnesses reported to Page Six Lyonne seemed out of it while she was led off the plane -- leading some to worry she'd relapsed again.