A Lakeside woman who was allegedly under the influence of an over-the-counter depressant at the time of a head-on freeway crash that killed a man in the other vehicle pleaded not guilty Wednesday to murder and other charges.

Kathleen Lucinda Sloan, 20, is also charged with gross vehicular manslaughter while intoxicated, felony DUI causing great bodily injury and hit- and-run.

About 3 p.m. Monday, Sloan was driving a sport utility vehicle on Interstate 8 near Dunbar Lane, just west of Alpine, when she pulled to the shoulder, made a U-turn and headed west in the eastbound lanes, Deputy District Attorney Luis Mendez said.

"Two vehicles managed to avoid colliding with her, but the victim's vehicle was struck and a man died at the scene,'' Mendez said.

The defendant, who was treated for a broken ankle and appeared at her arraignment in a wheelchair, was found to be under the influence of an unspecified central nervous system depressant at the time of the crash, Mendez said.

He said Sloan was involved in another collision before she made the U- turn, resulting in the hit-and-run charge.

Judge Charles Ervin set bail at $1 million. He scheduled a readiness conference for Nov. 12 and a preliminary hearing for Nov. 17.

The San Diego County Medical Examiner's Office identified the victim as Sergio Chan Mora, 54. His city of residence has not determined, and he could be a Mexican national, a coroner's official said.

Sloan, who works at a Subway sandwich shop and has no prior convictions, would face 15 years to life in state prison if convicted of second-degree murder, Mendez said.

"It's our position that if someone were to drive westbound on the eastbound part of the freeway on a Monday afternoon, that there is a high risk to human life,'' Mendez said.

He said no one suffered serious injuries in the first collision.