Levels of therapeutic antivenin and venom in a human snakebite victim.

An enzyme-linked immunosorbent assay was used to measure the levels of therapeutic antivenin (Antivenin [Crotalidae] Polyvalent, Wyeth-Ayerst) in serum and the levels of venom in the urine of a patient bitten by a western diamondback rattlesnake (Crotalus atrox). Serum and urine samples were taken on admission, during hospitalization, and during follow-up until 5 months after the bite. Photographs were taken of the bite site on admission to the hospital and during follow-up. Serum levels of therapeutic antivenin were highest between 1 and 3 days after the bite but were still detectable 46 days as well as 4 months after the bite. Crotalus atrox venom was detectable in the urine 4 days after the bite and was still measurable 6 days after the bite.