Drug regulatory authorities sometimes withdraw medicines from the market when they are suspected to have caused deaths – but when faced with these suspicions, how well do we investigate the relationship between drugs and adverse reactions?
To answer this question, we used information from our previously published paper to document medicines withdrawn from the market because they were suspected of causing deaths. We did not include medicines that caused deaths through overdose. We then searched the scientific literature to check whether studies were conducted to investigate the relationship between the withdrawn medicine and the adverse reaction which resulted in the deaths. In addition, we used a previously published algorithm to determine whether the withdrawals were justified in the first place.
What did we find?
We included 83 withdrawn medicines in the analysis. In almost 70% of cases, studies investigating the relationship between the medicine and the adverse reaction were conducted, and the studies showed a relationship in 63% of instances. In the few cases where the results of the studies were not consistent (n =3), the funding sources from which the studies were conducted differed. The speed with which the studies were conducted shortened with more recent withdrawals. In over 95% of instances, the withdrawals from the market were justified.
What do the results mean?
Drug regulatory authorities have rightly withdrawn medicines from the market when they were suspected of causing deaths. However, the delay to the withdrawals following reports of deaths (based on our previous research) indicates that people would have been unnecessarily exposed to the hazards from use of such medicines. Using an algorithm can result in quicker regulatory decisions when deaths are attributed to the use of a medicine. Collaboration between publicly and charity funded organisations can help strengthen the processes used to monitor and evaluate adverse reactions when deaths are attributed to medicines.
Dr Igho Onakpoya is a DPhil Student and Research Fellow in Evidence Based Practice and Pharmacovigilance.
Onakpoya IJ, Heneghan CJ, Aronson JK. Post-Marketing Regulation of Medicines Withdrawn from the Market Because of Drug-Attributed Deaths: An Analysis of Justification. Drug Saf. 2017 Feb 25. doi: 10.1007/s40264-017-0515-4.