Medical studies of poisonous land and sea snakes.

The comparative toxicity and pathophysiology of thirteen (13) of poisonous snakes indigenous to the area in and around Saudi Arabia were determined. Four snakes from the Viperidae family, six from the Elapidae family, and three representative sea snakes from the family Hydrophiodae were included. Anesthetized adult Beagle dogs and anesthetized monkeys were used in the study. Vital physiologic functions were recorded continuously as were changes in the blood coagulation system and any tissue damage produced by the venom at the site of envenomation. Venom was administered intravenously or by an actual bite. Venom from the snakes of the family Viperidae produced death in an average of 3 hours. The average lethal dose was 1.13 mg/kg. Depression of 1st and 2nd stage clotting factors and a decrease in fibrinogen levels and in platelet counts were observed with these venoms. Findings suggestive of intravascular coagulation also were observed with moderate hemolysis of the formed elements. Some local hemorrhage was seen at the site of envenomation. Venom from the Elapidae family of snakes produced death at an average of 1.7 hours. The average lethal dose was 0.70 mg/kg. Death appeared to be primarily due to respiratory paralysis after blockade at the neuromuscular junction. Only moderate hemolysis was seen with these venoms. No intravascular coagulation or tissue damage was seen. The venom of the family Hydrophiodae consistently produced death in less than 30 minutes at an average dose of 0.06 mg/kg. Tissue damage was not observed, and changes were not observed in the hematologic parameters monitored.(ABSTRACT TRUNCATED AT 250 WORDS)