Background: Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) are severe drug reactions associated with high mortality and multiple incapacitating sequelae. In the past 20 years, two large multinational case control studies, published in 1995 and 2008, had identified different degrees of drug association with SJS/TEN: 'strongly associated', 'associated', 'suspected' and 'not suspected' medications.
Objective: The aim of this study was to check the adequacy of mention of risk of SJS/TEN in the drug dictionaries most widely used by physicians in five European countries.
Study design: In each country one expert investigator looked at the most widely used drug dictionary (2009 edition) for mentions of risk of SJS/TEN. This was done for a predefined list of medications with a different degree of risk. The presence and clarity or absence of warning was compared with available evidence provided by published results from case-control studies.
Setting: The five countries participating in the RegiSCAR group: Austria, France, Germany, The Netherlands and the UK.
Results: A total of 3,268 drug descriptions of medications for systemic use were analysed, including all brands of 14 'strongly associated' drugs, 5 'associated' drugs and 12 widely used drugs with no established association. Discrepancies were found by country, and between descriptions for different brands of the same generic. Among 522 descriptions of 14 'strongly associated' drugs, only 5 did not mention the risk. For the 1,013 descriptions of 'associated' drugs, 3 % did not mention the risk. One-third of 'not suspected' drugs contained a specific or less specific warning (e.g. bullous cutaneous eruption). Warnings for 'strongly associated' medications were often as imprecise as those for 'not suspected' drugs.
Conclusion: Information on the risk of SJS/TEN in drug dictionaries needs improvement to enhance the quality of advice given by general physicians and to raise the understanding of risk by patients.