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.
Prospective, double blind, randomised, placebo controlled trial.
District general hospital in Sri Lanka.
105 patients with signs of envenomation after snake bite, randomised to receive either adrenaline (cases) or placebo (controls) immediately before infusion of antivenom serum.
Adrenaline 0.25ml (1:1000).
Main outcome measures
Development of acute adverse reactions to serum and side effects attributable to adrenaline.
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.
Use of 0.25ml 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.
- Antivenom serum is the only effective treatment for envenomation after snake bite
- Acute adverse reactions to the serum are common and include anaphylactic shock
- The prophylactic use of 1:1000 adrenaline in a dose of 0.25ml given subcutaneously immediately before infusion of antivenom serum significantly reduces the risk of acute adverse reactions