Management of paracetamol overdose in Malta

Abstract

Background: Paracetamol is the most frequent drug taken in overdose worldwide. This can result in liver failure and death unless appropriate medical intervention is provided early on following an overdose. The management of paracetamol overdose is complex and involves following proper published guidelines. Overdose with paracetamol is also common in Malta, yet, to date, there have been no studies which have identified how this overdose in managed locally. The aim of this present study was thus to determine and describe the management of paracetamol overdose at the primary teaching hospital in Malta, Mater Dei Hospital (MDH). Methods: Following ethical approvals from relevant ethics committees, a retrospective review was undertaken of all files and records of patients who presented MDH with paracetamol overdose between 1st January 2016 and 30th December 2020. Data was collected by reviewing fully anonymised data from the discharge letters and relevant information from the Central Processing Unit and Toxicology and Emergency Laboratories of patients admitted to MDH with paracetamol overdose. This included information related to patients’ demographics, description of the overdose, treatment pathways and patient outcomes, and laboratory investigations undertaken. Descriptive statistics were used to analyse the data thus collated. Results: 330 cases were listed in discharge letters as having been due to suspected paracetamol overdoses in the period under study. Thirty discharge letters were found to be duplicates and thus discarded. A threshold of paracetamol overdose was taken as being greater than 75mg/kg/day. Following approval of the relevant consultants, this resulted in a total of 112 cases identified and were included in this study. The average overdose size was 11 grams, and the most common formulation of paracetamol used in overdose was the tablet form (n = 110). Patients had a median of 26 years, and the majority were female (69%). In most cases, the intent of overdose was listed as undetermined in the discharge letters (n = 82). No statistically significant correlation was observed between the ages of patients and the intention of overdose. Most patients (46%) presented as having an unknown time of ingestion, and 65% (n = 73) were treated with N-acetylcysteine (NAC). All patients survived from this their paracetamol overdose. Only one case reported an adverse drug reaction to NAC. It is to be noted that five patients who were treated with NAC had a medication error in how the dose of NAC was estimated or administered. Discussion: This study has shown that in Malta, most patients who were seen with paracetamol overdose were females aged 20-30 years. The fact that most patients presented with an unknown time of ingestion limited the use of activated charcoal. Most cases were treated with NAC. The rates of adverse drug reactions reported due to its use (1%) and medication errors (11%) were lower than those reported in other studies. The study identified several limitations primarily related to the fact that this was a retrospective study, the fact that not all the consultants agreed to have their patients included in the study, missing data in patient records and a small sample size. Conclusion: The overall management of paracetamol overdose in MDH follows the guidelines available. However, it may be time to update the MDH paracetamol overdose guideline in line with the international recommendations, especially since massive paracetamol ingestions are not considered in the present guidelines and new therapies, such as fomepizole is now available.