A 27-year-old Rockland woman is facing drug and child endangerment charges after she passed out while apparently high on prescription medication, allowing her 3-year-old son to wander away from her apartment.

A passer-by found the boy playing in a drainage culvert on Saturday, according to a statement by police.

The boy told the passer-by that he did not know where he lived, but said that he had been watching “Scooby Doo” at home before he left the apartment. The adult searched a few nearby apartment complexes until finding one unit with a door open and “Scooby Doo” playing on the television inside.

When police arrived at the apartment, no one responded to knocks on the door, so police entered the home to find Mandy Dennison, 27, sleeping on a mattress in the living room. After several attempts to wake Dennison, she told police she did not know where her son was. She appeared to be under the influence of drugs, police said.

Police found in her possession the prescription drug clonazepam, which is used to treat seizure and panic disorders, and has the effect of a powerful sedative.

She was arrested and booked at the Knox County Jail, and the boy’s grandmother picked him up.

The following evening, police performing a bail check found her to be in possession of a different pharmaceutical for which she also did not have a prescription.

She was charged with endangering the welfare of a child, two counts of unlawful possession of drugs and violating conditions of her release.