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".
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Potential opportunities to prevent the Manchester attack were missed due to failures in dealing with the bomber, a report has found.
The man stopped in Staffordshire said the broken screen was not 'too much of a problem'.
The declaration on the future relationship between the UK and EU is "agreed at negotiators' level and in principle at political level".