The three-bag intravenous (IV) acetylcysteine regimen for paracetamol overdose is associated with frequent and long delays during treatment. This has not been previously studied in regard to the two-bag regimen.
Our primary aim was to compare the cumulative duration of delays during IV acetylcysteine infusion between the three-bag and two-bag regimens. Secondary aims were to compare the frequency of delays and to identify causes for delay.
This was a retrospective cohort study of patients receiving IV acetylcysteine for the treatment of paracetamol overdose, conducted at three Australian emergency departments. A cohort of patients treated with the three-bag regimen from October 2009 to October 2013 was compared to patients treated with the two-bag regimen from February 2014 to May 2020. Start times of each infusion were sourced from medical records and delays were calculated by comparing actual infusion time against prescribed time. Evidence of adverse drug reactions – gastrointestinal reactions and cutaneous and systemic non-allergic anaphylactoid reactions (NAARs) – were also recorded.
The three-bag cohort included 271 cases and the two-bag cohort included 598 cases. Delays were significantly shorter in the two-bag cohort, compared to the three-bag cohort: median delay 35 min (IQR: 15, 70) vs 65 min (IQR: 40, 105),  < 0.01. Delays longer than 1 h were less frequent in the two-bag cohort: 31% vs 51%,  < 0.01. NAARs were associated with significantly longer delays in both cohorts and were more frequent in the three-bag cohort.
The two-bag regimen was associated with significantly fewer and shorter delays. NAARs, which were more frequent in the three-bag cohort, were associated with significantly longer delays.