Comparison of oral and intravenous N-acetylcysteine administration in the treatment of acetaminophen poisoning

Intravenous or oral administration of N-acetylcysteine for acetaminophen poisoning has been a matter of controversy until recently. Each of these routes of administration has its advantages and disadvantages. This study was carried out to compare the effect of intravenous and oral acetylcysteine in the treatment of acetaminophen poisoning. This study was a parallel RCT study. The study population included all adults over 18 years of age who had been used more than 7. 5 gr acetaminophen during a 24 hour interval before admission to poisoning emergency ward of Baharloo Hospital in Tehran. Each group consisted of 30 patients. The study was approved by the Ethical Committee of Tehran University of Medical Sciences. Patients were divided into two groups by block randomization oral (72 h) and IV (20 h) N-acetylcysteine treatment groups. Liver enzyme levels were measured at baseline and then daily up to 72 hours after treatment. Side effects of drug administration in both groups were recorded. Data were entered into SPSS16 software and the data frequency tables were prepared. Chi-square، Mann-Whitney U and t-tests were used for data analysis. There were no statistically significant differences between the two groups in relation to different variables at baseline. The two groups showed no significant differences in regard to the mean serum levels of AST، ALT، bilirubin، and prothrombin time24، 48 and 72 hours after treatment and the therapeutic results were similar in both groups. Occurrence of nausea and hypotension after treatment in the oral treatment group was significantly higher than in the intravenous treatment group (57. 6٪ vs. 33. 3٪ and 12. 1٪ vs. Zero respectively) (p<0. 05). Considering other complications، no significant differences were noticed between the two groups. Considering the same safety and efficacy of both intravenous and oral acetylcysteine treatment، mild and manageable side effects of oral therapy on one hand and economic status and cultural attitudes in our community about admission and discharge of the patients، it seems more advisable to use oral treatment as the first therapeutic choice for acetaminophen poisoning in the absence of any contraindication to its use.