Magnesium sulfate and/or calcium channel blockers as co-adjuvant treatments to standard therapy for acute organophosphate insecticide poisoning: a systematic review and meta-analysis

Abstract

Introduction: Organophosphate insecticide poisoning remains a significant public health issue in low- and middle-income countries. Standard treatment involves atropine and pralidoxime or obidoxime, however adjunctive therapies like magnesium sulfate and calcium channel blockers may offer additional benefits. This review aims to evaluate the efficacy and safety of magnesium sulfate and/or calcium channel blockers as adjunctive treatments for organophosphate insecticide poisoning.

Methods: We performed a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, identifying randomized controlled trials that compared the use of magnesium sulfate or calcium channel blockers with standard treatment in hospitalized patients with organophosphate insecticide poisoning. Data were extracted regarding mortality, atropine requirements, hospital length of stay, and mechanical ventilation needs.

Results: No trials were identified for calcium channel blockers. Eight randomized controlled trials (total n = 549) across diverse settings evaluated magnesium sulfate as adjunctive therapy. The risk ratio for mortality (seven studies, total n = 469) comparing magnesium sulfate versus standard therapy was 0.37 (95% CI: 0.22-0.64). Magnesium sulfate also significantly reduced daily atropine requirements (mean difference = -23.27; 95% CI: -36.57 to -9.97). No significant differences were found for hospital length of stay or mechanical ventilation. Three studies monitored safety, with only one reporting transient hypotension at higher magnesium infusion rates.

Discussion: While the results suggest that magnesium sulfate may be a promising adjunct in the treatment of organophosphate insecticide poisoning, with potential benefits in reducing mortality and atropine dosage, the evidence is based on small studies with limited sample sizes. We were unable to find evidence to support the use of calcium channel blockers.

Conclusions: Intravenous magnesium sulfate may reduce mortality and atropine requirements in acute organophosphate insecticide poisoning, with a favorable safety profile. These findings should be interpreted with caution, and larger, well-designed randomized controlled trials are needed to determine the role of magnesium sulfate in organophosphate insecticide poisoning.

Keywords: Calcium channel blockers; magnesium sulfate; meta-analysis; organophosphate compound; poisoning; systematic review.