Use an As-Needed Antivenom Dosing Strategy for Rattlesnake Bites

CroFab antivenom is the treatment for rattlesnake envenomation, but it is expensive (~$2,300 per vial). After initial control of the envenomation, additional antivenom may be required to treat late recurrence. One approach, recommended by the manufacturer, is to give two vials at three timepoints: 6, 12, and 18 hours after initial control (maintenance strategy). Another approach is to observe the patient for 18 hours and give additional antivenom as needed (PRN) with signs of worsening tissue injury, thrombocytopenia, coagulopathy, or systemic illness.

These authors retrospectively compared outcomes of these two approaches at a single regional toxicology referral center in Arizona. They reviewed outcomes in 310 patients age 14 years or older…