N-acetylcysteine as an antidote for paracetamol poisoning: a multicenter study

Objective. To identify the most common problems related to use of N-acetylcysteine to reverse the toxic effects of paracetamol poisoning. Methods. Retrospective descriptive observational study of clinical records for patients treated for paracetamol poisoning in 4 emergency departments during 3 years (2017-2019). We analyzed epidemiologic, clinical, and care variables, especially those related to the suitability and safety of using N-acetylcysteine as an antidote. Results. We included 332 cases of poisoning of 260 patients (78%) were over the age of 16 years, and 242 (73%) were female. Two hundred sixty-eight poisonings (81%) were the result of voluntary intake. The elimination half-life was determined in 20 cases (6%). Gastrointestinal decontamination was incorrectly prescribed on 39 occasions (28%). Treatment with the antidote was begun in 195 cases (58.7%). No serious clinical signs or symptoms were present in 282 cases (85%). The correlation of paracetamol levels in urine was stronger with the amount of drug ingested voluntarily (R-2 =0.23) than with accidental intake (R-2 = 0.007). Predefined severity criteria were significantly related to reported dose ingested per body weight (P = .001) and the interval between intake and first medical assistance (P = .008). Conclusions. Even though clear protocols are available to guide the use of antidote treatment in cases of paracetamol poisoning, variability in fundamental aspects of management is excessive.