A Randomized Controlled Trial of Trypsin to Treat Brown Recluse Spider Bites in Guinea Pigs

• Published in: Journal of medical toxicology Vol. 10; no. 3; pp. 266 - 268
• Main Authors: Cabaniss, Wyman W., Bush, Sean, O’Rourke, Dorcas P., Fletcher, Paul F., Brewer, Kori L., Lertpiriyapong, Kvin, Punja, Mohan, Miller, Susan N., Meggs, William J.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.09.2014; Springer Nature B.V
• Subjects: Analgesia; Anesthesia; Animals; Antidotes; Biomedical and Life Sciences; Biomedicine; Bites; Brown Recluse Spider; Buprenorphine; Enzymes; Female; Guinea Pigs; Insect bites; Isoflurane; Lesions; Pain perception; Pharmacology/Toxicology; Placebo effect; Proteolysis; Randomization; Rodents; Skin diseases; Skin lesions; Spider Bites - drug therapy; Spiders; Statistical analysis; Toxicity; Toxicology Investigation; Toxins; Trypsin; Trypsin - therapeutic use; Variance analysis; Venom; Venom toxins; Spider bites; Trypsin
• ISSN: 1556-9039; 1937-6995; 1937-6995
• DOI: 10.1007/s13181-014-0405-4

Brown recluse spider bites result in necrotic skin lesions for which there is no known antidote. Since venom toxins are proteins, a proteolytic enzyme like trypsin might be effective in reducing toxicity. The aim of this study was to conduct a randomized controlled trial of trypsin to treat brown recluse spider bites in guinea pigs. Subjects were 18 female guinea pigs. Anesthesia for injections was inhaled isoflurane. Analgesia was 0.05 mg/kg of buprenorphine twice a day as needed. Intervention was intradermal injection of 30 μg of brown recluse venom (Spider Pharm, Yarnell, AZ). Immediately after envenomation, subjects were randomized to two groups of nine: trypsin 10 μg in 1 mL normal saline and 1 mL of normal saline. The primary outcome was lesion area over a 10-day time period. Statistical analysis was performed with repeated measures ANOVA. Mean lesion area was smaller but not statistically different in the placebo group. Maximum lesion size occurred at day 4 in both groups, when lesion area was 76.1 ± 108.2 mm 2 in the placebo group and 149.7 ± 127.3 mm 2 in the treatment group. P value was 0.15 for placebo vs. treatment. This study did not establish a role for trypsin as a treatment for brown recluse spider bites in a guinea pig model.