Publication:

Preclinical study comparing the antidotal effect of clonidine with atropine for the treatment of acute malathion poisoning in the albino rats

Background In developing countries 2–3 million people are acutely poisoned by organophosphorus (OP) pesticides every year. There is a pressing need for new affordable antidotes and in this context clonidine which has central effect (α2 agonist) has been evaluated in the albino rats presenting with signs or symptoms of acute malathion poisoning. And compared with atropine for the acte malathion poisoning in albino rats.

Methods This was a preclinical study conducted on albino rats of either sex weighing 100-150 grams were randomly divided into 4 groups (6/group). Malathion was given at the lethal dose of 54 mg/kg body weight (BW) by gavage to each group. Group 1: normal saline intraperioneal (i.p). Group 2: Post treated with atropine 1.5 mg/kg BW (i.p). Group 3: Pre treated with clonidine 1mg/ kg BW (i.p), 10 minutes priore malathion. Group 4: Pre treated with clonidine and post treated with atropine. The above groups were observed for straub tail, muscle fasciculation, piloerection, lacrimation, defecation/ urination; salivation, tremors, gasping and convulsion and were recorded at time 0, 15, 30, 45 and 60 minutes after poisoning. The latency of onset of tremors, loss of righting reflex and tremors were recorded. Results were presented as percentage occurrence and Mean ± SEM. Repeated measure one way ANOVA and Fisher’s Least Significant Difference post hoc test for comparison between groups. P-value of 0.05 or less was considered for statistical significance.

Results The central effects namely straubs tail and whole body tremors are significantly improved compared to control and atropine with clonidine group (p<0.05). However convulsion shows improve in atropine alone and atropine with clonidine groups. The overall survival time has significantly increased compared to control and atropine and atropine with clonidine (P<0.05).Clonidine has not shown any effect on survival time.

Conclusions Clonidine has some central protective effect in malathion poisoning. And it has not shown any effect on survival time. This issue needs further controlled studies.