Adverse drug reactions a big killer Bad reactions to pharmaceuticals account for 3% of deaths in Sweden. Daniel Cressey Pill popping can be bad for your health.Alamy More than 3% of all deaths seem to be caused by adverse reactions to medical drugs, according to new research. If substantiated by further work, this would make 'fatal adverse drug reactions' (FADRs) the seventh most common cause of death in Sweden, where the research was done (see 'Top killers'). Unsurprisingly, the team behind