Liver transplant associated with paracetamol overdose: results from the seven-country SALT study.

AIMS: Acute drug overdose, especially with paracetamol, may cause acute liver failure leading to registration for transplantation (ALFT). Population statistics and between-country differences for ALFT related to overdose have been poorly described. The aim of the present study was to evaluate overdose ALFT in the multi-country Study of Acute Liver Transplantation (SALT). METHODS: All adult overdose-related ALFT, with or without suicidal intent, in France, Greece, Ireland, Italy, the Netherlands, Portugal and the UK between 2005 and 2007 were identified from liver transplant registries and hospital records. These were compared with whole-country and per capita use of paracetamol. RESULTS: Six hundred cases of ALFT were identified in 52 of 57 eligible transplant centres, of which 114 involved overdose (72 intentional, 10 non-intentional, 32 uncertain). Overdose represented 20% of all-cause ALFT: Ireland 52%, UK 28%, France 18%, the Netherlands 8%, and Italy 1%. Overdose ALFT were mostly females (61%), mean age 33.6 ± 10.9 years. A total of 111 (97%) of the overdoses involved paracetamol. Event rates ranged from one ALFT for 20.7 tons of paracetamol in Ireland, to one for 1074 tons in Italy and one case in 60 million inhabitants over 3 years in Italy to one case in 286 000 inhabitants per year in Ireland. Per-country event rates for non-overdose ALFT exposed to paracetamol were between 2.5 and 4.0 per million treatment-years sold. CONCLUSIONS: Paracetamol overdose was found to represent one-sixth of all-cause ALFT. There was a 50-fold difference in Europe in the rates of paracetamol overdose ALFT, and a 200-fold difference per million inhabitants.

Causality of Drugs Involved in Acute Liver Failure Leading to Transplantation: Results from the Study of Acute Liver Transplant (SALT).

BACKGROUND: Several methods have been proposed to assess causality in drug-induced liver injury but none have been tested in the specific context of acute liver failure leading to transplantation (ALFT). OBJECTIVE: We took advantage of the Study of Acute Liver Transplant (SALT), a European case-population study of ALFT, to test different causality scales. METHODS: Causality was assessed by experts in SALT, a 7-country case-population study from 2005 to 2007 of adult otherwise unexplained ALFT, for all drugs found within 30 days prior to the date of initial symptoms of liver disease (index date), using information content, causality scales, and data circuit determined from a pilot study, Salome. RESULTS: The consensus points from Salome were to provide full data on drugs including international non-proprietary name (INN) and doses except for non-steroidal anti-inflammatory drugs (NSAIDs) and to use the World Health Organization (WHO) causality scale. In SALT, among the 9,479 identified patients, 600 (6.3%) were cases of ALFT, of which 187 had been exposed to drugs within 30 days, without overdose. In 130 (69.5%) of these the causality score was possible, probable, or highly probable. CONCLUSION: In ALFT cases, once other clinical causes have been excluded and drug exposure established within 30 days, the main discriminant characteristic for causality will be previous knowledge of possible hepatotoxicity.

Transplantation for acute liver failure in patients exposed to NSAIDs or paracetamol (acetaminophen): the multinational case-population SALT study.

BACKGROUND: Most NSAIDs are thought to be able to cause hepatic injury and acute liver failure (ALF), but the event rates of those leading to transplantation (ALFT) remain uncertain. OBJECTIVES: The aim of the study was to estimate population event rates for NSAID-associated ALFT METHODS: This was a case-population study of ALFT in 57 eligible liver transplant centres in seven countries (France, Greece, Ireland, Italy, The Netherlands, Portugal and the UK). Cases were all adults registered from 2005 to 2007 for a liver transplant following ALFT without identified clinical aetiology, exposed to an NSAID or paracetamol (acetaminophen) within 30 days before the onset of clinical symptoms. NSAID and paracetamol population exposures were assessed using national sales data from Intercontinental Marketing Services (IMS). Risk was estimated as the rate of ALFT per million treatment-years (MTY). RESULTS: In the 52 participating centres, 9479 patients were registered for transplantation, with 600 for ALFT, 301 of whom, without clinical aetiology, had been exposed to a drug within 30 days. Of these 301 patients, 40 had been exposed to an NSAID and 192 to paracetamol (81 of whom were without overdose). Event rates per MTY were 1.59 (95 % CI 1.1-2.2) for all NSAIDs pooled, 2.3 (95 % CI 1.2-3.9) for ibuprofen, 1.9 (95 % CI 0.8-3.7) for nimesulide, 1.6 (95 % CI 0.6-3.4) for diclofenac and 1.6 (95 % CI 0.3-4.5) for ketoprofen. For paracetamol, the event rate was 3.3 per MTY (95 % CI 2.6-4.1) without overdoses and 7.8 (95 % CI 6.8-9.0) including overdoses. CONCLUSIONS: ALF leading to registration for transplantation after exposure to an NSAID was rare, with no major difference between NSAID. Non-overdose paracetamol-exposed liver failure was twice more common than NSAID-exposed liver failure.

Administrative complexities for a European observational study despite directives harmonising requirements.

PURPOSE: For pharmacoepidemiological studies in Europe, accessing data should require only authorisation by the relevant data protections committees, as expected from the 1995 Data Protection Directive (95/46/EC). Our experience from a multinational observational study across seven European countries shows that this is certainly not the case. METHODS: The study was a multicentre, multinational, case-population study in European liver transplant centres in seven countries, retrospectively evaluating a 3-year period. Before data collection started, the procedures to obtain the necessary authorisations for the participating countries were defined. REMARKS: In France, a single opinion from a single data protection committee was enough to start the study. In Italy, Portugal, Greece and the UK, there was a national authority, but the hospitals requested the approval by their local committees/bodies irrespective of whether the authorisation of the national committee came after or before that of local ones. In Ireland, only one hospital participated, and the opinion of its ethics committee was sufficient. In the Netherlands, the opinion of the institutional review board of the local coordinating centre was necessary to obtain the opinions from the institutional review boards of the other hospitals. The information requested by the different committees and the time to obtain the approvals varied, even within the same country. CONCLUSION: This degree of complexity and disharmony, and resulting cost, was observed in a simple retrospective study. Regulators will need to be aware that these time-consuming, expensive and useless complexities must be factored in when estimating the time and cost of a study.