Bill Clinton says Americans need to know about the potentially fatal danger of mixing alcohol with opioids.
The former US president said schoolchildren were not being warned of the risks.
He was speaking after delivering a keynote speech at the World Patient Safety Summit in London on Saturday.
"One friend of mine had a daughter having trouble with her marriage. He was desperate, he called her every day."
"He couldn't find her and the police went into her apartment and found her sitting there, watching television, stone dead with a glass of wine in front of her."
He said America was in the grip of an opioid crisis.
"It has been a problem for a decade or more in America and nobody tells these kids when they go to school that you can die if you do this.
"You cannot mix these two things."
Australian Associated Press