NEUTRALIZATION OF AMAZONIAN CROTALINE SNAKE VENOMS BY BRAZILIAN ANTIVENOMS

MUNIZ E. G. (1), NORONHA M. D. N. (1), NASCIMENTO S. P. (2), SILVA-HAAD J. J (3), LÓPEZ-LOZANO J. L. (1)

(1) Fundação de Medicina Tropical do Amazonas, Amazonas, Brazil, (2) Instituto Nacional de Pesquisas da Amazônia, Boa Vista, Roraima, Brazil, (3) Hospital Regional de Letícia, Colômbia.

Efficacy of brazilian antivenoms to neutralized the several toxic effects induced by Bothrops atrox and Crotalus durissus ruruima venoms from Amazonas and Roraima State – Brazil, were studied. Antivenoms (AV) used were antibothropic (AB) or anticrotalic (AC) from Fundação Ezequiel Dias (FUNED), Instituto Butantan (IB), Instituto Vital Brazil (IVB) and polyvalent - IB/IBEX to neutralized B. atrox or C.d.ruruima venom activities. Potency of antivenoms against lethal activity of B. atrox venom was 2.4 to 3.5 mg venom/ml AV, but the minimum potency of AB recommended is 1ml neutralizing 5 mg of B. jararaca venom. B. atrox (Manaus region) defibrinating venom activity was neutralized by all antivenoms tested ED100 <125 µlAV/mg venom, but to B. atrox venom from Letícia region was <125 to 500 µlAV/mg venom. All antivenoms neutralized coagulant activity of B. atrox venoms ED < 25 µlAV/mg venom and 125 lAV/mg venom from Manaus and Letícia regions, respectively. Hemorrhagic effect was neutralized by all antivenoms ED100 ranging 375 to 750 µlAV/mg venom. Antivenoms showed neutralizing ability against phospholipase activity ED100 375 to 750 µlAV/mg venom. C. d. ruruima venoms showed qualitative and quantitative differences in the biological activities with presence or absence of hemorrhagic and crotamine activities. Lethal activity was efficiently neutralized by AC and polyvalent antivenoms, 3.1 to 5.0 mg venom/mlAV, but AC antivenoms in 5µlAC/µg venom rations, showed low neutralization efficiency of hemorrhagic activity (3 to 50%). Our results showed that brazilian antivenoms have neutralizing activity on B. atrox or C.d. ruruima venoms but with quantitative variations on the biological venom activities studied. Clinical trials are required as the better criterion for the efficacy evaluation of antivenoms.

KEY WORDS: snake venoms, antivenoms.

FINANCIAL SUPPORT: FAPEAM, FINEP, FMT-AM.

CORRESPONDENCE TO: EMIRO MUNIZ, Centro de Ofidismo Prof. Paulo Friedrich Buhrnheim, FMTAM. E-mail: emiromuniz28@hotmail.com