Schools must do more to educate pupils about the risks of prescription drugs, a bereaved mother has said.
Kim Webster's son William Horley, 17, died in 2018 after taking the opiate tramadol with a friend.
Teens are "naive" about the risks of recreationally taking prescription drugs and lessons are needed to counter a "false sense of security," she said.
According to the ONS there were 220 tramadol deaths in 2018 - the second-highest level on record.
Mrs Webster, who now gives drug-awareness lectures in schools, warned that young users of prescription medicines - like tramadol and xanax - believe they are "safe because doctors prescribe it".
Her son William, of Herne Bay, Kent, had been due to join the Army, but "paid the ultimate price" for a "naive moment", she said.
"His whole life was waiting for him and he had it planned out exactly what he wanted to do," she said.
When reflecting on her loss, she feels "as if my heart is squeezed to the point that I can't catch my breath".
Mrs Webster said schools should have a set curriculum, covering the dangers of recreationally using prescription drugs, adding: "It's as important as English, Maths or Science".
Department for Education (DfE) guidance, which comes into force in September 2020, says secondary school pupils should have an "awareness of the dangers of drugs which are prescribed".
Liz McCulloch, of drug reform organisation VolteFace, said the guidance was a positive development, but feared it could become a "tick-box exercise," with pupils only required to receive one lesson in primary school and another in secondary.
Teachers are left to work out for themselves what are the "the facts and risks" about a "new and emerging issue" without any additional training and no requirement to use recommended resources, she said.
The DfE guidance says it intends to give schools across the country the freedom to shape their health education curriculum to meet the needs of their pupils.