Reduction of some organophosphate insecticides toxicity in mice by diphenhydramine [Research Note].

The effect of the antihistamine diphenhydramine on the toxicity of some organiphosphate insecticides was determined in female mice. The LD50 values of diazinon, methidathion, malathion and fenitrothion were 76, 10.5, 650 and 917 mg/kg of female mice, orally, respectively. Diphenhydramine [20 mg/kg] injected subcutaneously 5 minutes after dosing mice with these insecticides markedly increased their LD[50] values by 71, 114, 62 and 25%, respectively. The results suggested the usefulness of diphenhydramine in reducing the toxicity of organophosphate insecticides