1) Anti-Cobra Venom Serum: SPECIES: Naja kaouthia (Manufacturer: Myanma Pharmaceutical Industries, Burma)
2) Anti-Viper Venom: SPECIES: No species identified (Manufacturer: Myanma Pharmaceutical Industries, Burma)
3) Bivalent Venom Serum: SPECIES: Naja kaouthia (Manufacturer: Myanma Pharmaceutical Industries, Burma)

a) CHINA
b) INDONESIA
c) JAPAN
d) PHILIPPINES
e) TAIWAN
f) THAILAND
g) AUSTRALIA
h) CENTRAL AMERICA

1) Hypotension has been reported with the following antivenoms: SAIMR polyvalent snake antivenom, Haffkine Indian polyspecific antivenom, and Antivenom (Crotalidae) Wyeth Polyvalent (Moran et al, 1998; Heard et al, 1999; Ariaratnam et al, 2001), and is theoretically possible with any antivenom therapy.

1) Antivenom therapy can be associated with the development of an early anaphylactoid reaction (EAR), which occurs within minutes (10 to 60 minutes) of receiving therapy. It is usually due to complement activation by the antivenom, and not IgE mediated hypersensitivity (Warrell, 1995; Singh et al, 2001).
2) COMMON SYMPTOMS: Generalized urticaria, fever, itching, palpitation, nausea and vomiting can develop with an early anaphylactoid reaction, and usually responds to epinephrine, antihistamines and steroids (Isbister et al, 2006; Singh et al, 2001).
3) INCIDENCE: The incidence and severity of early reactions may be dose and rate related, but this has not been proven in prospective studies (Malasit et al, 1986).
4) PRODUCT VARIATION: Manufacturers have attempted to reduce adverse reactions by developing methods to purify antivenoms using pepsin or papain digestion and chromatographic techniques to obtain F(ab')2 or Fab' preparations (Otero-Patino et al, 1998).

1) SKIN TESTING: Skin or conjunctival sensitivity testing has been shown to be unpredictable in detecting early reactions to antivenom therapy or to late serum sickness effects (Malasit et al, 1986; Chippaux & Goyffon, 1998; Singh et al, 2001).

1) CROTALIDAE POLYVALENT IMMUNE FAB ANTIVENOM: An observational study was conducted to determine the incidence of possible hypersensitivity reactions in adults and children treated with Crotalidae polyvalent immune Fab (ovine) (CroFab; FabAV) following envenomation by a North American rattlesnake. A total of 93 patients with a mean age of 34.5 years (range: 16 months to 91 years) received a mean dose of 12 vials of antivenom (range: 4 to 32 vials). Five (5.4%) patients developed acute hypersensitivity reactions. Of those 5 patients, only one patient developed a severe reaction requiring treatment with epinephrine, antihistamines and steroids with discontinuation of antivenom therapy. The remaining 4 patients developed relatively minor symptoms (treated effectively with antihistamine and/or steroid therapy), and were able to complete a full course of antivenom therapy (Cannon et al, 2008).
2) SRI LANKA RUSSELL VIPER/COMPARATIVE TRIAL: Ariaratnam et al (2001) reported fewer adverse events among patients receiving an ovine Fab fragment antivenom (PolongaTAb{TM}) than an equine IgG antivenom purified with pepsin to produce F(ab')2 fragments to treat daboia russelii russelii (Russell's viper) envenomations (Ariaratnam et al, 2001).
3) OVINE FAB: In one study, 4 (57%) of 7 patients developed early anaphylactoid reaction (EAR) after receiving ovine Fab antivenom (Meyer et al, 1997).
4) EQUINE POLYVALENT: Fourteen (35.9%) of 39 patients developed EAR, with 9 patients developing effects within 2 hours of antivenom therapy. Urticaria was the most common symptom reported, followed by fever, chills, mild hypotension, generalized rash and nausea (Otero et al, 1996).
5) TIGER SNAKE ANTIVENOM: During a 2 month multicenter study of snake bites in Australia, a high rate of early anaphylactoid reaction (EAR) were observed following the administration of tiger snake antivenom. Of the 14 patients that received tiger snake antivenom, 11 patients developed immediate hypersensitivity reaction which were mild in 5 patients, moderate in 3, and severe in 3 cases. Symptoms of anaphylaxis occurred in 6 patients and 9 patients were treated with epinephrine. In all patients, antivenom was restarted with 4 patients requiring a concomitant epinephrine infusion to complete antivenom therapy (Isbister et al, 2006).
6) BOTHROP ANTIVENOMS: A randomized, blinded, comparative trial of one pepsin digested {F(ab')2} and two whole IgG antivenoms was conducted to determine overall safety and efficacy of each product. It was found that the whole IgG antivenom obtained by caprylic acid fractionation resulted in less early anaphylactoid reactions (11.1%) than the F(ab')2 product (36.7%) or the monovalent whole IgG antivenom (81.8%). The authors concluded that pepsin digested antivenoms do NOT produce the lowest incidence of EARs; further study of this method was suggested (Otero-Patino et al, 1998).

1) In two trials, the overall rate was 16% (6/38 patients) for the sheep derived antivenom. Due to limited experience with FabAV, further studies are indicated (Dart & McNally, 2001).
2) INCIDENCE RATE