An In Vitro Method for Assessing the Efficacy of Antivenom Against Hemiscorpius lepturus Venom

BACKGROUND: Hemolyis of red blood cells is a serious toxic effect commonly found among patients envenomed by Hemiscorpius lepturus scorpion. OBJECTIVES: The aim of the present study was to evlaute the efficay of the avaible polyvalent antivneom in preventing this phenomena. MATERIALS AND METHODS: Using a red blood cell fragility test, the anti-hemolytic effectiveness of a new antivenom serum against Hemiscorpius lepturus venom was investigated. Hemolysis was measured using spectrophotometry. RESULTS: Addition of venom (2, 10, 20, and 40 µg/ml) to 0.5 ml of 5% washed red blood cell suspension produced concentration-dependent hemolysis. Both the pre-incubation of red blood cell suspensions with various concentrations of antivenom (4%, 10%, and 20% v/v) and the co-administration of antivenom with 20 µg/ml venom resulted in concentration-dependent protection against hemolysis. Both the methods resulted in protection against hemolysis at the antivenom concentration of 20% (v/v). However, the inhibition of hemolysis after 24 h was found to be greater for red blood cell suspensions preincubated with antivenom (75% inhibition) than for red blood cell suspensions that were co-administered with antivenom and venom (50% inhibition). CONCLUSIONS: The results suggest that the antivenom against H. lepturus venom is useful in inhibiting hemolysis produced by the venom, but the duration of protection is relatively short and appropriate measures need to be taken, depending on the patients’ clinical progress, to re-administer the antivenom at intervals less than 8 h. This proposed treatment method merits further clinical assessment.