20.500.12556/DiRROS-29037 Clinical efficacy and pharmacokinetics of antivenom Viperfav® in Vipera ammodytes ammodytes envenomation Background: In Europe, Vipera ammodytes ammodytes (Vaa, nose-horned viper) is considered the most venomous of the European vipers. The antivenom Viperfav®, composed of polyvalent equine F(ab′)2 fragments, is effective against Vipera aspis, Vipera berus and Vaa. Objectives: This study aimed to evaluate the clinical efficacy and pharmacokinetics of Viperfav in Vaa envenomations. Methods: Patients presenting with Vaa snakebite and treated with intravenous Viperfav were included. Clinical manifestations and laboratory findings were assessed on admission to the Emergency Department, prior to antivenom therapy, and monitored throughout hospitalization. Blood samples were collected on arrival and at defined intervals after Viperfav administration. Venom and antivenom concentrations in serum were determined by ELISA and subjected to pharmacokinetic analysis. Results: Twenty-one patients bitten by Vaa and classified with a severity score of 2b on the modified Audebert clinical severity scale received a single intravenous dose of Viperfav within 4 h of the bite. Viperfav attenuated the progression of local symptoms and prevented the development of new systemic manifestations. The serum concentrations of F(ab′)2 fragments reached 196 µg/mL, far exceeding the venom concentration at admission (35 ng/mL). The prolonged elimination half-life of Viperfav (49 h) corresponded with the absence of recurrent symptoms after a single dose. Bradycardia or hypotension occurred in 10% of patients; no cases of anaphylaxis or serum sickness were observed. Conclusions: A single intravenous dose of Viperfav demonstrated clinical efficacy and a favourable pharmacokinetic profile in Vaa envenomed patients when administered within hours of the bite. snake venom antivenom Viperfav kačji strup protistrup Viperfav true false true Angleški jezik Slovenski jezik Neznano 2026-04-17 15:12:28 2026-04-17 15:12:28 2026-04-18 03:52:07 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Opis vira z dne 12. 11. 2025; str. 1-12 iss. 11, [article no.] 1431 Vol. 17 Nov. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 577 1999-4923 10.3390/pharmaceutics17111431 256886275 RAZ_Kurtovic_Tihana_2025.pdf RAZ_Kurtovic_Tihana_2025.pdf 1 32BB9324D6D8C9F9536B3327846B455B ed5192f8d4c0af47fc183413e52f14bb1280ecf73b6fcda4c635333b05fcc16c 317a05d3-3a5f-11f1-a7d2-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=43357 https://www.mdpi.com/1999-4923/17/11/1431 1 17b51fd6-3a5f-11f1-a7d2-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=43356 Univerzitetni klinični center Ljubljana 0 0 0