Antivenoms

Schwartz HJ, Squillace DL, Sher TH, Teigland JD, Yunginger JW Studies in stinging insect hypersensitivity postmortem demonstration of antivenom IgE antibody in possible sting-related sudden death. Am J Clin Pathol 1986 85 607-610. 

The Indian folk medicine, called Ayurvedic medicine, can be traced back 3000-5000 years and was practiced by the Brahmin sages of ancient times. The treatments were set out in sacred writings called Vedas. The material medica are extensive and most are based on herbal formulations. Some of the herbs have appeared in Western medicines, such as cardamom and cinnamon. Susruta, a physician in the fourth century ad, described the use of henbane as antivenom for snakebites. 

Antivenom—Protein produced by the body s immune system that binds to a poisonous substance from a snake or insect. 

Animals are used for the manufacture of a number of biological products, e.g. polio vaccine (monkeys), snake antivenoms (horses and goats), rabies vaccine (rabbits, mice and... 

Patients with systemic symptoms should be considered for treatment with antivenoms. Clinicians are not in agreement as to the exact criteria, and few randomized controlled trials have been conducted. 

Where the snake has been identified and specific antivenom is available, then this should be used. However, since treatment is urgent, and identification of snakes is difficult, in many Asian countries polyvalent antivenom is used. The Indian anti-snake venom (ASV), manufactured by Serum Institute India, Pune, and Haffkine Bio Pharmaceutical Corporation, Mumbai, consists of hyperimmune horse serum against four common snakes - cobra, common krait, Russell s viper and saw-scale viper. 

More sophisticated antivenoms, containing antibody binding fragments, are less immunogenic than whole antibody antivenoms, and seem safe and effective. 

Offerman SR, Bush SP, Moynihan JA, Clark RF. Cro-taline Fab antivenom for the treatment of children with rattlesnake envenomation. Pediatrics 2002 110(5) 968-71. 

Antivenom is the only specific antidote to snake venom. Antivenom is immunoglo-... 

Theakston RD, Phillips RE, Warrell DA, Galagedera Y, Abeysekera DT et al. (1990) Envenoming by the common krait (bungarus caeruleus) and sri lankan cobra (naja naja naja) efficacy and complications of therapy with haffkine antivenom. Trans R Soc Trap Med Hyg 84 301-8 Thesleff S (1960) Supersensitivity of skeletal muscle produced by botulinum toxin. J Physiol 151 598-607... 

McClain, C., Snake bites rise antivenom supply remains spotty, Arizona Daily Star, Sept. 9, 2001, p. Al. 

Allergenic extracts Antitoxins, antivenoms, venoms Blood, blood components, plasma-derived products (e.g., albumin, immunoglobulins, clotting factors, fibrin sealants, proteinase inhibitors), recombinant and transgenic versions of plasma derivatives... 

Although treatment is possible using antivenins (antivenom), the combinations of toxins in a particular snake venom can vary, which means that they need to be as specific as possible. Antidotes to the effects can sometimes also be used, for example anticholinesterase substances which are used in treatment of the death adder bite. The antidote stops the... 

A drug that reduces body temperature in fever, antivenins (antivenom)... 

Clinically, mamba bites may not provoke a major local reaction. If neurotoxins are injected by the bite, clinical symptoms appear within minutes to hours. Clinical signs of impairment of neuromuscular transmission (ptosis, ophthalmoplegia, bulbar symptoms, or generalized weakness) dictate administration of antivenom (Ludolfph, 2000). For Elapidae (coral snakes) venom is known that is a potential neurotoxin and may cause paresthesias, weakness, cranial nerve dysfunction, confusion, fasciculations, and lethargy. Often mild local findings, diplopia, ptosis, and dysarthria are common early symptoms. Patients die because of respiratory paralysis. In these cases, early and aggressive... 

Acconci C, Legallais C, Vijayalakshmi M, and Bueno SMA. Depyrogenation of snake antivenom serum solutions by hollow fiber-based pseudobioaffinity filtration. J. Membr. Sci. 2000 173 235-245. 

Subcutaneous adrenaline has been used to prevent the immediate adverse effects of snake antivenom, although evidence of its efficacy is scanty (2). A large chnical trial is under way in Sri Lanka. 

Nuchpraryoon I, Garner P. Interventions for preventing reactions to snake antivenom. Cochrane Database Syst Rev 2000 (2) CD002153. http //www.update-software.com/ abstracts/ab002153.htm. 

Antivenom is most effective by intravenous injection. The range of venoms neutralized by an antivenom is usually stated in the package insert. If the biting species of snake is known, the appropriate monospecific antivenom should be used. In countries where several species produce similar signs, snakebite victims are treated with polyspecific antivenom, which contains a lower concentration of specific antibody to each species than the monospecific antivenom. 

Antivenom treatment can be complicated by early reactions (anaphylaxis), pyrogenic reactions, or late reactions (serum sickness-type). The incidence and severity of early reactions is proportional to the dose of antivenom and the speed with which it enters the blood stream (1,2). These reactions usually develop within 10-180 minutes of starting antivenom therapy. The reported incidence of early reactions after intravenous antivenom in snakebite patients, which ranges from 43% (3) to 81% (4), appears to increase with the dose and decrease when refined antivenom is used and administration is by intramuscular rather than intravenous injection. Unless patients are watched carefully for 3 hours after treatment, mild reactions can be missed and deaths misattributed to the envenoming itself. In most cases symptoms are mild urticaria, nausea, vomiting, diarrhea, headache, and fever however, in up to 40% of cases severe systemic anaphylaxis develops, with bronchospasm, hypotension, or angioedema. However, deaths are rare (5). 

Pyrogenic reactions result from contamination of antivenom by endotoxin-like compounds. High fever develops 1-2 hours after treatment and is associated with rigors, followed by vasodilatation and a fall in blood pressure. Febrile convulsions can occur in children. Patients should be cooled and given antipyretic drugs by mouth, powdered and washed down a nasogastric tube, or by suppository. 

Premawardhena AP, de Silva CE, Fonseka MM, Gunatilake SB, de Silva HJ. Low dose subcutaneous adrenaline to prevent acute adverse reactions to antivenom serum in people bitten by snakes randomised, placebo controlled trial. BMJ 1999 318(7190) 1041-3. 

Ariaratnam CA, Sjostrom L, Raziek Z, Kularatne SA, Arachchi RW, Sheriff MH, Theakston RD, Warrell DA. An open, randomized comparative trial of two antivenoms... 

Malasit P, Warrell DA, Chanthavanich P, Viravan C, Mongkolsapaya J, Singhthong B, Supich C. Prediction, prevention, and mechanism of early (anaphylactic) antivenom reactions in victims of snake bites. BMJ (Clin Res Ed) 1986 292(6512) 17-20. 

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