A Single Dose of Viperfav(TM) May Be Inadequate for Vipera ammodytes Snake Bite: A Case Report and Pharmacokinetic Evaluation

Toxins (Basel). 2016 Aug 19;8(8):244. doi: 10.3390/toxins8080244.


Viperfav(TM) is a commercial F(ab')₂ antivenom prepared against European vipers venom. It is safe and effective for treating envenomation caused by Vipera aspis and Vipera berus. Therapeutic efficacy for treating Vipera ammodytes ammodytes (V. a. ammodytes) envenoming has not been yet described, although protective efficacy has been demonstrated in preclinical studies. We report on a 32-year-old man bitten by V. a. ammodytes who was treated with Viperfav™. Viperfav™ promptly reduced local extension and improved systemic pathological signs, but 24 h after the incident a recurrence of thrombocytopenia occurred despite a favorable pharmacokinetic profile with systemic clearance (1.64 (mL·h(-1))·kg(-1)) and elimination half-life (97 h) among the highest ever reported. The recommended dose of Viperfav™ for V. aspis and V. berus bites may be inadequate for serious V. a. ammodytes envenomations. Following V. a. ammodytes bite, serial blood counts and coagulation profiles should be performed to help guide Viperfav™ treatment, along with supplemental administration as indicated.

Keywords: F(ab’)2 antivenom pharmacokinetics; Vipera ammodytes ammodytes envenomation; Viperfav™ antivenom treatment.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Antivenins / administration & dosage*
  • Antivenins / blood
  • Blood Cell Count
  • Blood Coagulation / drug effects
  • Blood Coagulation Tests
  • Drug Monitoring / methods
  • Half-Life
  • Humans
  • Immunoglobulin Fab Fragments / administration & dosage*
  • Immunoglobulin Fab Fragments / blood
  • Male
  • Metabolic Clearance Rate
  • Snake Bites / blood
  • Snake Bites / diagnosis
  • Snake Bites / drug therapy*
  • Time Factors
  • Treatment Outcome
  • Viper Venoms*
  • Viperidae*


  • Antivenins
  • Immunoglobulin Fab Fragments
  • Viper Venoms
  • Viperfav