title: A randomized, double-blind, placebo-controlled trial of antivenom for local effects of green pit viper bites.
abstract: Although systemic administration of antivenom can promptly reverse coagulopathy, efficacy on local effects of viper venom remains to be determined. Currently, there has been no proven specific treatment for snakebite patients with severe local effects. This study is a randomized, double-blind, placebo-controlled trial. Patients bitten by green pit vipers (Trimeresurus albolabris or T. macrops) with marked limb swelling, but no severe coagulopathy requiring antivenom, were randomized to receive either equine F(ab')2 antivenom, or placebo. Twenty-eight cases were included, 14 in each group, and they had their limb circumferences measured on days 1, 2, 4 and 6 after interventions. The percentage reduction in limb circumference was significantly better in the antivenom group compared with the placebo group (ANOVA, P = 0.03), especially in the first 24 h (1.14 vs. 3.62%, in placebo and antivenom group, respectively, P = 0.014). The reduction in pain score was similar. The plasma venom levels were not different at presentation but lower in the antivenom group 24h after intervention (P = 0.033). These data suggest that intravenous antivenom could accelerate local oedema resolution in humans. However, the degree is not clinically significant, and, therefore, general use is not recommended.
authors.affiliation: Department of Medicine, Faculty of Medicine, Chulalongkorn University, Rama IV Road, Patumwan, Bangkok 10330, Thailand. fmedprn@md2.md.chula.ac.th
authors.forename: Ponlapat
authors.initials: P
authors.lastname: Rojnuckarin
authors.forename: Walee
authors.initials: W
authors.lastname: Chanthawibun
authors.forename: Jureeporn
authors.initials: J
authors.lastname: Noiphrom
authors.forename: Narumol
authors.initials: N
authors.lastname: Pakmanee
authors.forename: Tanin
authors.initials: T
authors.lastname: Intragumtornchai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000997:Antivenins / Q000627:therapeutic use*; D003435:Crotalid Venoms / Q000097:blood; D004311:Double-Blind Method; D004487:Edema / Q000139:chemically induced / Q000188:drug therapy; D005121:Extremities / Q000293:injuries; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy; D012909:Snake Bites / Q000188:drug therapy* / Q000473:pathology; D016896:Treatment Outcome; D017841:Trimeresurus
chemical_list: D000997:Antivenins; D003435:Crotalid Venoms