Increasing frequency and fatality of poison control center reported exposures involving medication and multiple substances: data from reports of the American Association of Poison Control Centers 1984-2013

Context: Medication use has become increasingly prevalent in the United States, with up trending use of both prescription and over the counter medication. The increasing use and availability of medication may be changing the nature of poisoning fatality.Objective: To evaluate changes in fatal poisoning over time, with respect to fatalities involving one or more medications, using annual reports published by the American Association of Poison Control Centers (AAPCC).Materials and methods: AAPCC annual reports were reviewed from 1984 to 2013. Data from tables in each annual report titled Number of Substances Involved in Human Exposure Cases and Summary of Fatal Exposures were abstracted. Fatality rates and changes in these rates over time were calculated for exposures to 1, 2, or 3 substances. All substances detailed in Summary of Fatal Exposures tables were then coded as medication or non-medication. The percentage of fatalities involving 1, 2, or 3 medications was calculated and trended over time. Subset analysis was performed to compare the periods 1984-2005 and 2006-2013 in order to limit confounding from changes in reporting. Secondary analysis linking the number of substances cases were exposed to and the fatality rate was performed for data from 2006-2013.Results: There were 59,866,357 human exposures and 29,659 fatalities reported from 1984 to 2013. There were 49.5 fatalities per 100,000 exposures. The majority of fatalities (52.2%) involved more than one substance, although multiple substances were involved in only 8.3% of exposures. Fatality rates increased over time and were higher for cases involving multiple substances. Medications were involved in 79.2% of fatalities, a percentage that increased from 70% in the 1980s to nearly 90% after 2010. In recent years, the majority of fatalities have involved multiple medications. For data from 2006-2013 there was a strong association between fatality rate and number of substances involved in an exposure (221 additional fatalities per 100,000 exposures for each additional substance involved in an exposure).Discussion and conclusion: Multiple substance exposures have become a greater percentage of cases reported to the AAPCC and have higher fatality rates than single substance exposures. The majority of fatal poisonings reported to the AAPCC between 1984 and 2013 involved medication. The percentage of fatal poisonings involving medication increased over the interval, as did the percentage of fatalities involving more than one medication. Fatalities involving multiple medications are now the most common type of fatal poisoning reported to the AAPCC.