Canadian status of "not acceptable" drugs as evaluated by Prescrire: A cohort study.

The majority of the not acceptable drug-indications were approved by Health Canada. The difference between when Prescrire and Health Canada examined the evidence for these drug-indications is unlikely to explain the difference in their evaluations. A change in regulatory standards at Health Canada may be one factor behind the presence of these drugs. To what degree those drugs led to more harms than benefits for patients who are taking them needs to be urgently investigated. Finally, the reasoning behind Health Canada's approval of these drugs should be interrogated.