On October 19, 2016, the Superior Court of Québec released the first ever decision of a Canadian Court ruling on the merits of a pharmaceutical product liability common issues trial. In this decision, the Plaintiffs were alleging that the healthcare company was responsible for psychiatric reactions experienced by the class members while taking an antibiotic.

The healthcare company retained McCarthy Tétrault LLP after certification of the class action by the Superior Court of Québec.

Justice Suzanne Hardy-Lemieux dismissed the action, concluding that the Plaintiffs had not met their burden of demonstrating that the antibiotic was the cause of the psychiatric reactions suffered by the class members. She stated that in the presence of strong evidence demonstrating the absence of causation, the Court could not base its decision on coincidental events that reveal, at best, low possibilities of causation. More specifically, Justice Hardy-Lemieux concluded that because of the blood-brain barrier protection, there was a minimal possibility that the drug could reach the brain and induce psychiatric reactions.

There are several takeaways in this judgment:

  • The inclusion of ²adverse reactions² in the Product Monograph is not proof that causation is recognized by the manufacturer;
  • The use of the Naranjo scale as well as case reports are inappropriate and insufficient to establish causation between a drug and adverse events; and
  • Individuals who consume generic versions of a drug have no claim against the manufacturer of the innovator drug due to the lack of connection at law.

This case is a reminder that once a class action is certified, Plaintiffs, on the merits, still have the onus to establish causation on the balance of probabilities. In a pharmaceutical product liability case, such demonstration needs to be based on solid scientific and expert evidence in order to be successful.