Incidence of fatal adverse drug reactions: a population based study

Abstract

* Although drugs generally are safe and effective therapies for numerous diseases, adverse drug reactions do occur and may even be fatal. * The incidence of fatal adverse drug reactions in hospitalized patients has been estimated to be approximately 5%. * In previous studies the incidence of fatal adverse drug reactions in hospitalized patients has been reported, but the incidence of fatal adverse drug reactions in the general population is largely unknown. * Fatal adverse drug reactions account for approximately 3% of all deaths in the general population. * Haemorrhages amount to almost two-thirds of the fatal adverse drug reactions and antithrombotic agents are implicated in more than half of the suspected fatal adverse drug reactions. * Fatal adverse drug reactions are estimated to be the seventh most common cause of death in Sweden. To determine the incidence of fatal adverse drug reactions (FADRs) in a Swedish population. Every seventh randomly selected deceased in three counties in South-east Sweden during 1 January 2001-31 December 2001 was identified in the Cause of Death Register. Relevant case records (hospitals and/or primary care centres and medicolegal files) were reviewed to identify suspected drug-related fatalities. Of 1574 deceased study subjects, 49 (3.1%; 95% CI 2.2%, 4.0%) were suspected to have died from FADRs. The most common suspected FADRs were gastrointestinal haemorrhages (n = 18; 37%), central nervous system haemorrhages (n = 14; 29%), cardiovascular disorders (n = 5; 10%), other haemorrhages (n = 4; 8%) and renal dysfunction (n = 3; 6%). The drugs most commonly implicated in FADRs were antithrombotic drugs (n = 31; 63%), followed by nonsteroidal anti-inflammatory drugs (NSAIDs) (n = 9; 18%), antidepressants (n = 7; 14%) and cardiovascular drugs (n = 4; 8%). Of all the 639 fatalities in hospital 41 (6.4%; 95% CI 4.5%, 8.3%) were suspected to be due to FADRs. The medical burden of FADRs is significant. Haemorrhages were seen in a majority of the FADRs; antithrombotic agents or NSAIDs were implicated in most of these events. These results suggest that preventive measures should be taken to reduce the number of deaths caused by drugs.