Trimelarsen was injected intravenously into 246 dogs positive for microfilariae. No side effects were observed in any dog immediately after injection. The most remarkable filaricidal effect was noticed when 5mg/kg of the drug was injected four times at intervals of 4-8 hours. This effect was hardly reduced even when the drug was diluted, stored at low temperature, and used within 36 hours.
The blood level of trimelarsen reached a peak immediately after injection and decreased to about 70% 6 hours later. No residual arsenic was detected from any organ at autopsy conducted 25 days after injection.
