Effectiveness of calcium channel blockade for organophosphorus and carbamate pesticide poisoning – study protocol for an open label, pragmatic, 3-arm RCT repurposing two widely available medicines

Figures & data

Figure 1. Systematic review of clinical studies of magnesium sulphate or dihydropyridines in OP or carbamate insecticide poisoning. Reproduced with permission from [22].

Table 1. Schema of sample collection timing, as appropriate for patient survival or discharge.

	t = 0h	t = 1h	t = 4h	t = 12h	t = 24h	t = 48h	t = 96h	Discharge
SAMPLES
blood	X	X	X	X	X	X	X	X
(plasma)	X		X		X	X	X	X
(serum)	X	X	X	X	X	X	X	X
(red cells)	X		X		X	X	X	X
urine	X		X	X	X	X	X	X
ASSAYS
Mg++		Y		Y	Y	Y
nimodipine				Y
pesticide	Y
ChE assay	Y	Y	Y	Y	Y	Y	Y	Y

Y: Assay time, X: sample taken.

Figure 2. Map of Bangladesh showing the districts of currently (as of March 2023) active (red colour) study hospitals and possible future (yellow colour) study hospitals throughout the country. The active study hospitals cover an estimated 33% of the country’s population.

Brvar M, Chan MY, Dawson AH, et al. Magnesium sulphate and calcium channel blocking drugs as antidotes for acute organophosphorus insecticide poisoning – a systematic review and meta-analysis. Clin Toxicol. 2018;56(8):725–736. doi:10.1080/15563650.2018.1446532.

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