Nick Bonnie, 30, collapsed at a nightclub in Manchester in the early hours of Saturday.
Mr Cameron said: "This is a tragic death. We've seen too many of these".
When asked if the Government has a grip on its drugs policy, he said: "The focus of Government has quite rightly been on education...and treatment".
He added that he disagreed with the Chief Constable of Durham's call for some drugs to be decriminalised as "it would make them more available and lead to more problems".
More top news
The study reveals cases of slave driving and human trafficking suffering delays, being prematurely shelved or being overlooked entirely.
David Clarke was arrested after a four-hour standoff in which two members of staff were taken hostage. Both escaped unharmed.
New York's attorney general launched the civil rights investigation after dozens of women accused Harvey Weinstein of sexual harassment.