Lipid emulsion for acute organophosphate insecticide poisoning - a pilot observational safety study

Organophosphate (OP) poisoning is an important public health concern in South-Asia especially in the farming population. Treatment of OP poisoning has remained unchanged since decades and case fatality is 10-40% despite best supportive care, anticholinergic agents and oximes. A new antidote is the need of the hour. Lipid emulsion being inexpensive, easily available and effective in management of other lipid soluble toxins may be a novel option. However, safety has not been established and efficacy is limited to animal studies and case reports in humans with OP poisoning.

An open-label pilot study was undertaken to establish the safety of lipid emulsion in OP poisoning. Patients with symptomatic OP poisoning, meeting the inclusion and exclusion criteria were treated with 100 mL of 20% intravenous lipid emulsion (after consent) in addition to standard of care. They were monitored for change in hemodynamic parameters, change in hematology and biochemical parameters at various intervals of time after initiation of therapy. Morbidity, mortality, and occurrence of adverse effects were compared with historical control group.

Forty patients with symptomatic OP poisoning were enrolled in the study group. No significant change in hemodynamic parameters (pulse rate, systolic, diastolic blood pressure, and mean arterial pressure) or in hematology and biochemical parameters were seen. No adverse effects were noted. Compared to historical controls, no change in mortality was noted, although there was reduced duration of mechanical ventilation, hospital stay, and early resolution of hypernatremia.

This study evaluates the safety of lipid emulsion in OP poisoning. Absence of change in hemodynamic parameters and adverse effects suggests lipid emulsion may be safe for this indication. Large randomized controlled trials are now required to assess clinical efficacy. ClinicalTrials.gov number: NCT03564574.