Dosage regimen of methylene blue and its comparative therapeutic efficacy with tolonium chloride and ascorbic acid in induced acute nitrate toxicity in goats

Abstract

Nitrate toxicity was induced in 21 healthy female goats by oral administration of 1 % potassium nitrate @1.3g/kg b. wt. with the appearance of clinical symptoms of dyspnoea, tachycardia and brownish discolouration of mucous membrane along with high methaemoglobinemia (46.45±3.01to50.39±2.59%) at 2 hr of toxicity when different drug formulations were tried. To find out the most effective dose, first 1 % methylene blue at varying doses of 1,2,3, and 4 mg/kg b.wt. was tried in 4 groups of 2 goats each and repeated after 4hr. The dose of 3 and 4 mg/kg b. wt. was, respectively, 50% and 100% effective with clinical recovery of dyspnoea and colour of visible mucous membrane changing from brown to red, reduction in methaemoglobinemia to 9.25% and 5.89% and survival of 1 and both the animals, respectively, within 24 hr of therapy. The other 2 doses were ineffective with the death of all the goats. Subsequently methylene blue @ 4 mg/kg b. wt. was tried in 3 more goats to substantiate the above observations and got similar encouraging result. Tolonium chloride (1 %) @20 mg/kg b.wt. were also evaluated for their therapeutic efficacies separately in 2 groups of 5 goats each with significant improvement in toxicity symptoms and haemato-biochemical profile within 24 hr and all the animals survived. Comparative therapeutic evaluation revealed the superiority of tolonium chloride over methylene blue and ascorbic acid in nitrate toxicity in goats.