Methods: A placebo-controlled, double-blind, cross-over trial of intravenous edrophonium (Tensilon test) was conducted among 18 adults admitted with neurotoxic envenoming in the snake-bite of the Shaheed Ziaur Rahman Medical College and Hospital Bogra Bangladesh. The patients were randomly selected to receive intravenous edrophonium/placebo first and then acted as their own case/control by receiving other drugs.
Results: They were examined at baseline (before injection) and at an interval of 0 (after injection), 5, 10, 15, and 20 minute(s) after receiving medication. Five parameters noted were: ptosis (percentage of iris uncovered), duration of upward gaze, peak flow rate, interdental cleft distance, and maximum blow pressure. The study was attempted in 23 patients but had to be abandoned in 5 due to development of respiratory arrest during the trial. There was significantly more improvement in ptosis and endurance of upward gaze after administration of edrophonium than after administration of placebo. The improvement was more marked at the 5th minute - the mean difference (±SD) in the percentage of iris that was uncovered was 16 (51±28.91 vs. 36±21.60), and the mean difference in the number of seconds of upward gaze was 11 (23 vs. 13). The forced vital capacity and ability to open the mouth (inter-dental cleft) also improved after administration of edrophonium. Marked improvement was observed among few patients in their ability to talk, swallow, and cough.
Conclusions: Anticholinesterases are beneficial in the management of neurotoxic envenoming by the snakes of the part in Bangladesh, and use of anticholinesterase routinely in patients with neurotoxic envenoming is recommended.