The role of a combination of N-acetylcysteine and magnesium sulfate as adjuvants to standard therapy in acute organophosphate poisoning: A randomized controlled trial

BACKGROUND: Mortality in acute organophosphate (OP) poisoning remains high despite current standard therapy with atropine and oximes. Due to dose-limiting side effects of atropine, novel therapies are targeting other putative mechanisms of injury, including oxidative damage, to reduce atropine dosage. OBJECTIVES: N-acetylcysteine (NAC) and magnesium sulfate (MgSO(4)) have different mechanisms of actions and should act synergistically in OP poisoning. In this study, we wanted to evaluate whether this novel combination, used as an adjuvant to standard care, could improve clinical outcomes. METHODS: The study was conducted in the Emergency Department and ICU of AIIMS Bhubaneswar (a tertiary care center and government teaching institute) between July 2019 and July 2021. Eighty-eight adult patients with history and clinical features of acute OP poisoning were randomly allocated (1:1) into two groups. The Study group received 600 mg NAC via nasogastric tube thrice daily for 3 days plus a single dose of 4 g Inj. MgSO(4) IV on first day and the Control group received suitably matched placebo (double-blinding) – in addition to standard care in both the groups. The primary outcome measure was to compare the total dose of Inj. Atropine required (cumulative over the entire treatment duration) between the control group and the study group receiving NAC and MgSO(4). The secondary outcome measures were lengths of ICU and hospital stays, need and duration of mechanical ventilation, the differences in BuChE activity, oxidative stress biomarkers – MDA and GSH levels, the incidences of adverse effects including delayed sequalae like intermediate syndrome and OPIDN, and comparison of mortality between the two groups. RESULTS: Data from 43 patients in Control and 42 patients in Study group was finally analyzed. The baseline parameters were comparable. Total atropine requirements were lower in the Study group [175.33 ± 81.25 mg (150.01–200.65)] compared to the Control [210.63 ± 102.29 mg (179.15–242.11)] [Mean ± SD (95% CI)], but was not statistically significant. No significant differences in any of the other clinical or biochemical parameters were noted. CONCLUSION: The N-acetylcysteine and MgSO(4) combination as adjuvants failed to significantly reduce atropine requirements, ICU/hospital stay, mechanical ventilatory requirements, mortality and did not offer protection against oxidative damage.