Complications of crotaline antivenom therapy in the United States

• Published in: Clinical toxicology (Philadelphia, Pa.) Pa.), 2005-10, Vol.43 (6), p.708-708
• Main Authors: Stanford, C F, Olsen, D, Bogdan, G M, Dart, R C
• Format: Article
• Language: English
• ISSN: 1556-3650

Complications of therapy with CroFab and Antivenin Crotalidae Polyvalent (ACP) include recurrent venom effects and acute hypersensitivity reactions (AHRs). Reports on their incidences vary widely, due to limited samples and methodological differences. This study was undertaken to identify rates of recurrence (REC) and AHRs using treatment records from multiple poison centers (PC). Treatment and outcome data were systematically abstracted from PC cases involving Crotaline AV therapy in human patients during 2004. Initial control (IC) was defined as a trend toward normalization of all local and systemic venom effects. REC was defined as re-emergence of either swelling (SREC) or coagulopathy (CREC: PLT24 hrs post-AV were considered for REC. Of 344 cases of Crotaline envenomation from 24 states, 243 (71%) patients were treated with AV. Over 90% (222) were given CroFab, 4% (9) received ACP, and 5% (12) received both AVs or unreported AV. IC was achieved in 83% of patients, after a median of one dose of CroFab or ACP. Rate of AHRs was significantly greater for ACP (33%) than for CroFab (7%, p = .03). All AHRs responded to antihistamines and steroids. A total of 99 records qualified for REC. Despite 2 REC after ACP, there were insufficient data in this preliminary analysis to calculate REC rate for ACP (n = 4). REC rate for CroFab was 22% (21/95): SREC was present in 14 of these patients and CREC in 9. One SREC/CREC was accompanied by abnormal bleeding. Median REC onset was 72 hours after IC. Of all cases, one patient developed persistent dysfunction (hemodialysis, no REC). IC of venom effects was often achieved with only one dose of AV. AHRs were more common with ACP than with CroFab. REC was observed with both AVs. REC after CroFab was less common than in pre marketing trials (27-50%), more common than in other post-marketing studies (8-19%), and often with earlier onset (with or without maintenance doses). Medical risk associated with REC remains questionable.