H istory of Scorpion Sting Treatment in North America and Rationale for the Use in the United States of a Mexican Scorpion-Derived Antivenom
Boyer, Leslie and McNally, Jude
Arizona Poison and Drug Information Center, University of Arizona Health Sciences Center, Tucson, Arizona, USA
Background: Techniques of management for Centruroides scorpion envenomation have been developed separately in Mexico and in the United States in the past century. In Mexico, where 250,000 stings are reported annually, historic treatment with a variety of pharmaceutical agents has gradually given way to the use of antivenom. In the United States, where 8000 stings are reported annually, a similar historic pattern has lead to two schools of thought, one favoring the relative efficacy of antivenom and the other favoring the relative safety of intensive observation and sedation. Notable differences between the Mexican and U.S. thresholds for use of antivenom derive from differences in the available agents (highly refined F(ab)2 in Mexico, whole IgG in the U. S.) and from the difference in availability of hospital intensive care units.
Rationale: North American Centruroides species of importance to human health range from northern Arizona through southern Mexico. The venoms of all medically important species contain analogous ion-channel toxins. The F(ab)2 product produced using the venoms of southern Mexican species shows strong affinity for venom of the Arizona/Sonora scorpion species. Highly refined F(ab)2 antivenoms should provoke considerable fewer adverse effects than do whole IgG antivenoms. The currently available Mexican product, in theory, should be safer than the current Arizona antivenom and more effective than hospitalization and sedation, in victims of stings by the Arizona species.
Discussion: Debate in Arizona over the local approach to scorpion sting treatment has seldom taken into consideration the potential advantages of "fabotherapy," in part because no F(ab)2 product has been submitted for FDA consideration and in part because past cultural, economic, and language barriers have separated the U.S. and Mexican scientific and medical communities. Because of the low incidence of severe envenomation in the United States, it is prohibitively costly to develop a distinct local F(ab)2 product. Collaboration between the two countries would facilitate validation of safety and efficacy data necessary for US FDA approval.
Conclusions: Victims of Centruroides envenomation in the United States would benefit from the use of F(ab)2 antivenom developed for use in Mexico.
Publication Dates
-
Publication in this collection
08 Oct 2002 -
Date of issue
Dec 2001
