When it comes to the root of events that triggered the emergence of pharmacovigilance, regulatory affairs, adverse event recognition and keeping records of bad medical experiences by 'good' patients, everyone considers thalidomide  as the starting point. I guess I wrote very briefly about it here. But in fact thalidomide and its nasty teratogenic effects recognised in the 1960s cannot be considered the sole potentiator of utter vigilance and attentive pharmacological screening. There was yet another product that also contributed to this wind of change, but because of a lesser visual impact turned out to be the poor relative of a family of historical drugs that would change our relationship with medicines forever.
COMING ON AUGUST THE 20TH!!!
 Grootheest, K. (2003). "The Dawn of Pharmacovigilance". International journal of Pharmaceutical Medicine, 17(5), pp. 195-200.