Antivenom for critically ill children with neurotoxicity from scorpion stings.
BACKGROUND
Clinically significant scorpion envenomation by Centruroides sculpturatus produces a dramatic neuromotor syndrome and respiratory insufficiency that often necessitate intensive supportive care. We hypothesized that a scorpion-specific F(ab')(2) antivenom would promptly resolve clinical symptoms in children with this syndrome.


METHODS
In a randomized, double-blind study, the efficacy of scorpion-specific F(ab')(2) antivenom, as compared with placebo, was assessed in 15 children 6 months to 18 years of age who were admitted to a pediatric intensive care unit with clinically significant signs of scorpion envenomation. The primary end point was the resolution of the clinical syndrome within 4 hours after administration of the study drug. Secondary end points included the total dose of concomitant midazolam for sedation and quantitative plasma venom levels, before and after treatment.


RESULTS
The clinical syndrome resolved more rapidly among recipients of the antivenom than among recipients of placebo, with a resolution of symptoms in all eight antivenom recipients versus one of seven placebo recipients within 4 hours after treatment (P=0.001). More midazolam was administered in the placebo recipients than in the antivenom recipients (mean cumulative dose, 4.61 vs. 0.07 mg per kilogram of body weight; P=0.01). Plasma venom concentrations were undetectable in all eight antivenom recipients but in only one placebo recipient 1 hour after treatment (P=0.001).


CONCLUSIONS
Among critically ill children with neurotoxic effects of scorpion envenomation, intravenous administration of scorpion-specific F(ab')(2) antivenom resolved the clinical syndrome within 4 hours, reduced the need for concomitant sedation with midazolam, and reduced the levels of circulating unbound venom. (ClinicalTrials.gov number, NCT00685230.)
VIPER Institute, University of Arizona Health Sciences Center, 1295 N. Martin Ave., Tucson, AZ 85721-0202, USA. boyer@pharmacy.arizona.edu
Leslie V
LV
Boyer
Andreas A
AA
Theodorou
Robert A
RA
Berg
Joanne
J
Mallie
Ariana
A
Chávez-Méndez
Walter
W
García-Ubbelohde
Stephen
S
Hardiman
Alejandro
A
Alagón
D000293:Adolescent; D000818:Animals; D000941:Antigens / Q000097:blood; D000997:Antivenins / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000627:therapeutic use; D007223:Infant; D007262:Infusions, Intravenous; D008297:Male; D009468:Neuromuscular Diseases / Q000188:drug therapy* / Q000209:etiology; D011446:Prospective Studies; D065008:Scorpion Stings / Q000150:complications / Q000188:drug therapy*; D012604:Scorpion Venoms / Q000276:immunology*; D012605:Scorpions
D000941:Antigens; D000997:Antivenins; D007140:Immunoglobulin Fab Fragments; D012604:Scorpion Venoms