Four teenagers who were hospitalized Friday morning after overdosing on drugs had taken Xanax and marijuana, the Clark County Sheriff’s Office said Monday.Three of the teens were discovered unconscious outside in an east Vancouver neighborhood, prompting the sheriff’s office to investigate. A fourth teenager showing signs of an overdose was taken to a local hospital by a parent.All of the teens, who are between 17 and 18 years old, are friends; three are Heritage High School students. They were treated at local hospitals and have since been discharged.In a news release, the Clark County Sheriff’s Office said it “cautions the public on the dangers of mixing any drugs, legal or illegal. The combinations can have life-threatening effects.” Those under a doctor’s care should keep medication secure, so that it can’t be accessed by other people, the sheriff’s office said.Xanax is a prescription sedative used to treat anxiety and panic disorders.The sheriff’s office originally suspected the teens had overdosed on opioids. Emergency responders did administer Narcan, an opioid overdose reversal drug, but it’s unclear how many of the teens received the drug, said Clark County Sheriff Office Cmdr. Mike McCabe.Police are continuing to investigate Friday’s incident.