WHITE PLAINS, N.Y. — The defense at Kerry Kennedy’s drugged-driving trial introduced a medical journal article on Thursday in support of her testimony that she didn’t realize she had accidentally taken a sleeping pill before getting behind the wheel.

The August 2013 New England Journal of Medicine article said data showed that people taking the sleeping pill zolpidem “frequently do not recognize their impaired state.”

Kennedy testified Wednesday that she didn’t remember anything that happened as she drove on a New York interstate one summer day in 2012 — swerving out of her lane, hitting a tractor-trailer and blowing a tire.

And she says she never sensed that the drug was having an effect.

“If I realized I was impaired I would have pulled over,” Kennedy said Wednesday at her trial in White Plains.

The conclusion of the article on zolpidem was read from the witness stand Thursday by Dr. David Benjamin, a clinical pharmacologist who said he was involved in the testing of zolpidem as the manufacturer sought FDA approval in the 1990s.

It would be even more difficult for someone who didn’t know they had taken the drug “to understand what was going on,” he said.

On cross examination, Benjamin said “a reasonable person” would check a prescription bottle before taking the drug. But when prosecutor Doreen Lloyd asked him to say it was Kennedy’s fault, the defense objected and the judge sustained the objection.

Benjamin was the last witness to be called. Closing arguments were set for Thursday afternoon.

Kennedy, the ex-wife of New York Gov. Andrew Cuomo, daughter of Sen. Robert F. Kennedy and niece of President John F. Kennedy, claims she took the pill thinking it was her thyroid medication.

The prosecution has argued that even if she took the sleeping pill accidentally, Kennedy violated the law by failing to pull over as she felt it taking effect.