DRUGS AND PLANTS WHICH ANTAGONIZE VENOM O R POTENTIATE ANTIVENOM

Dendroaspis jamesoni (Elapidae) and Echis ocellatus (Viperidae) are re sponsible for most of severe envenomation in Cameroon. Toxicity of ven oms of these two species has been measured using mice according to the method of SPEARMAN, & KARBER. The effect on experimental envenomation of various drugs (atropine promethazine, neostigmine, hydrocortisone, pentosane sulfuric polyester; heparin, tranexamic acid and aminocapro ic acid) and plant extracts (Schumanniophyton magnificum, Bidens pilos a, Securidaca longepedunculata and Garcinia lucida) has been observed associated or not with the antivenom lpser Afrique(R) (SAV). The venom of D. jamesoni contains neurotoxins agonising and antagonising acetyl choline. The toxicity of the venom did not depend on the route of inje ction. Atropine, promethazine, neostigmine and hydrocortisone protecte d animals against a venom dose up to 2 LD50. Moreover atropine and pro methazine potentiated the SAV. Similar results have been obtained with extracts from S. magnificum and B. pilosa. The venom of E. ocellatus induces haemorrhage and necrosis. The toxicity increased by 3-fold whe n the venom was injected through intravenous or intraperitoneal route, compared to intramuscular route. Pentosane sulfuric polyester and tra nexamic acid protected mice against doses up to 3 LD50. Pentosane sulf uric polyester, hydrocortisone, heparin and aminocaproic acid increase d the SAV protective titre by 50 %. However tried plant extracts weakl y antagonised the venom and did not potentiate the SAV.