Low dose subcutaneous adrenaline to prevent acute adverse reactions to antivenom serum in people bitten by snakes: randomised, placebo controlled trial. (1/204)

OBJECTIVE: To assess the efficacy and safety of low dose adrenaline injected subcutaneously to prevent acute adverse reactions to polyspecific antivenom serum in patients admitted to hospital after snake bite. DESIGN: Prospective, double blind, randomised, placebo controlled trial. SETTING: District general hospital in Sri Lanka. SUBJECTS: 105 patients with signs of envenomation after snake bite, randomised to receive either adrenaline (cases) or placebo (controls) immediately before infusion of antivenom serum. INTERVENTIONS: Adrenaline 0.25 ml (1:1000). MAIN OUTCOME MEASURES: Development of acute adverse reactions to serum and side effects attributable to adrenaline. RESULTS: 56 patients (cases) received adrenaline and 49 (controls) received placebo as pretreatment. Six (11%) adrenaline patients and 21 (43%) control patients developed acute adverse reactions to antivenom serum (P=0.0002). Significant reductions in acute adverse reactions to serum were also seen in the adrenaline patients for each category of mild, moderate, and severe reactions. There were no significant adverse effects attributable to adrenaline. CONCLUSIONS: Use of 0.25 ml of 1:1000 adrenaline given subcutaneously immediately before administration of antivenom serum to patients with envenomation after snake bite reduces the incidence of acute adverse reactions to serum.  (+info)

Sequential randomised and double blind trial of promethazine prophylaxis against early anaphylactic reactions to antivenom for bothrops snake bites. (2/204)

OBJECTIVE: To investigate the efficacy of the H1 antihistamine promethazine against early anaphylactic reactions to antivenom. DESIGN: Sequential randomised, double blind, placebo controlled trial. SETTING: Public hospital in a venom research institute, Sao Paulo, Brazil. PARTICIPANTS: 101 patients requiring antivenom treatment after being bitten by bothrops snakes. INTERVENTION: Intramuscular injection of promethazine (25 mg for adults and 0.5/kg for children) or placebo given 15-20 min before starting intravenous infusion of antivenom. MAIN OUTCOME MEASURES: Incidence and severity of anaphylactic reactions occurring within 24 hours after antivenom. RESULTS: Reactions occurred in 12 of 49 patients treated with promethazine (24%) and in 13 of 52 given placebo (25%); most were mild or moderate. Continuous sequential analysis indicated that the study could be interrupted at the 22nd untied pair, without preference for promethazine or placebo. CONCLUSION: Prophylaxis with promethazine does not prevent early reactions. Patients should be observed carefully during antivenom infusion and the subsequent few hours.  (+info)

Comparative characterisation of Russell's viper (Daboia/Vipera russelli) venoms from different regions of the Indian peninsula. (3/204)

Russell's viper (Daboia/Vipera russelli) venom from different regions of India was subjected to chromatographic, electrophoretic, biochemical and immunological analysis. The elution profiles from ion-exchange chromatography and protein banding pattern from SDS-PAGE showed a significant variation in the constituents of venoms. The acidic proteins are found to be predominant in the venoms of eastern and western regions while basic proteins are the major contributors of the northern and southern regional venoms. The major variation of phospholipases A(2) in the venom samples of India may be described as: southern regional venom is rich in basic, toxic PLA(2) while this activity showed a dramatic decrease as one moves towards west, north and eastern regions of India. In addition, the caseinolytic, TAME-hydrolytic, anticoagulant, oedema-inducing and haemorrhagic activities of the venoms have also varied from one region to another. The muscle specimens of mice injected with venoms of different regions showed variable change in the muscle fibre damage and cell morphology. The eastern regional venom is most lethal among all the venoms. The lethal potencies for four regional venoms vary as: eastern>western>southern>northern. The polyclonal antibodies prepared against the venom of southern region showed cross-reaction with the venoms of other regions, but the extent of cross-reaction and diffusion patterns are different. However, the polyclonal antibodies prepared against southern regional venom showed no protection against lethal toxicity of other regional venoms.  (+info)

A new monospecific ovine Fab fragment antivenom for treatment of envenoming by the Sri Lankan Russell's viper (Daboia Russelii Russelii): a preliminary dose-finding and pharmacokinetic study. (4/204)

Russell's viper is the most important cause of life-threatening snake bite and acute renal failure in Sri Lanka. Only equine polyspecific antivenoms imported from India are available. They have not proved effective clinically or in clearing venom antigenemia and they frequently cause reactions. In an attempt to reduce mortality and morbidity, a new monospecific ovine Fab fragment antivenom (PolongaTab; Therapeutic Antibodies, Inc., London, United Kingdom) was raised against Sri Lankan Russell's viper venom. In a preliminary dose-finding study in 35 patients, an initial dose of 3-4 g restored blood coagulability permanently and stopped systemic bleeding, even in severely envenomed patients. Venom antigenemia disappeared within 1 hr of antivenom treatment but recurred, probably as a result of continued absorption of venom from the site of the bite, after the rapid clearance of therapeutic antibody. Twelve patients (34%) experienced early reactions that were usually mild and always responded to epinephrine.  (+info)

Comparative study on the ability of IgG and F(ab')2 antivenoms to neutralize lethal and myotoxic effects induced by Micrurus nigrocinctus (coral snake) venom. (5/204)

A comparative study was performed on the ability of IgG and F(ab')2 antivenoms to neutralize lethal and myotoxic activities of Micrurus nigrocinctus venom. Both antivenoms were adjusted to a similar neutralizing potency in experiments where venom and antivenoms were preincubated prior to injection. No significant differences were observed between IgG and F(ab')2 antivenoms concerning neutralization of lethal effect in rescue experiments, i.e., when antivenom was administered intravenously after envenomation. However, F(ab')2 antivenom was more effective in prolonging the time of death when subneutralizing doses were administered immediately after venom injection. Both products partially reversed the binding of M. nigrocinctus alpha-neurotoxins to acetylcholine receptor in vitro. The IgG and F(ab')2 antivenoms effectively neutralized venom-induced myotoxicity when administered intravenously immediately after envenomation, although neutralization was poor if antivenom injections were delayed. Intramuscular injection of venom promoted diffusion of antivenom antibodies throughout muscle tissue, and F(ab')2 diffused to a higher extent than IgG molecules. Thus, despite the observation that F(ab')2 antivenom was more effective than IgG antivenom in prolonging the time of death when subneutralizing doses were administered immediately after envenomation, no major differences were observed in antivenom neutralization of lethal and myotoxic effects or in their capacity to reverse neurotoxin binding to the acetylcholine receptor.  (+info)

A novel Fab-based antivenom for the treatment of mass bee attacks. (6/204)

The frequency of mass bee attacks has dramatically increased in the Americas following the introduction and spread of the aggressive Africanized 'killer' bee (Apis mellifera scutellata). As yet no specific therapy is available, which led us to develop an ovine Fab-based antivenom as a potential new treatment. Sera from sheep immunized against the venom contained high levels of specific antibodies, as demonstrated by ELISA and by small-scale affinity chromatography, against both whole (A. m. mellifera) venom and purified melittin. A nerve muscle preparation was used to show the myotoxic effects of the venom and neutralization by the antivenom. Antivenom neutralizing ability was also demonstrated using assays for venom phospholipase A2 and in vivo activities. Venom from both European and Africanized bees appeared identical when analyzed by acid-urea gel electrophoresis. This antivenom may therefore provide the first specific therapy for the treatment of mass envenomation by either European or Africanized 'killer' bees.  (+info)

Short report: treatment of snake envenomations by a new polyvalent antivenom composed of highly purified F(ab)2: results of a clinical trial in northern Cameroon. (7/204)

A clinical trial was conducted in 2 health centers in northern Cameroon to assess the safety and efficacy of a new polyvalent antivenom composed of highly purified and pasteurized F(ab')2 (FAV-Africa). Forty-six patients with objective signs of envenomation, including 67% with hemorrhage, were included in the study. Each patient received at least 20 ml of FAV-Africa by direct, slow intravenous injection; 172 10-ml ampules were administered. All patients were clinically cured after treatment. Two patients (4.3%) showed minor immediate adverse events that may have been related to FAV-Africa (induration, light-headedness); no other treatment-related adverse event occurred. No patient had serum sickness. This trial confirms the safety of FAV-Africa administered by intravenous injection and its efficacy in the treatment of snake envenomations in sub-Saharan Africa.  (+info)

Preparation of a potent anti-scorpion-venom-serum against the venom of red scorpion (Buthus tamalus). (8/204)

A number of children and adults, especially pregnant women succumb to the sting by red Scorpion (Buthus tamalus) in Konkan region--particularly on the coastal line. No specific antiserum or any other antidote is available to treat a victim of scorpion bite and hence the need to prepare a potent antiserum. Red Scorpion (B. tamalus) venom is a mixture of a number of protein moieties and neurotoxins of low molecular weight. Therefore, the venom is poor in antigenic composition and it is difficult to get antibodies specific to neutralise lethal factor/factors. Using Bentonite as an adjuvant and extending the period of immunization a potent antiserum has been prepared capable of neutralising the lethal factor/factors. In vivo testing carried out in albino mice, guinea pigs, dogs and langurs confirms this finding and shows that the antiserum is quite effective in neutralising the scorpion venom to save the life of envenomated animals.  (+info)

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